Name: 1122-17-4|2,3-Dichloromaleic anhydride|97%
Brand: Ambeed
SKU: A842166
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1
[ 108-31-6 ]
[ 1122-17-4 ]

Yield	Reaction Conditions	Operation in experiment
93%	With pyridine; thionyl chloride at 0 - 75℃; Inert atmosphere;
65.9%	With pyridine; thionyl chloride at 75℃; for 2.66667h; Cooling with ice;	1 (1) Synthesis of 2,3-dichloromaleic anhydride In a dry 250 mL round bottom flask,9.8 g (0.1 mol) of maleic anhydride,Under ice bath conditions,Thionyl chloride (100 mL, 1.38 mol)Magnetic stir,Pyridine 16.6 mL (0.2 mol) was dropwise added with a constant pressure dropping funnel,1h drops completed.After the addition is completed,Continue stirring under ice bath for 1 h.Remove the ice bath,Oil bath heated to 75 ,Reflux 40min.Vacuum distillation to remove residual thionyl chloride,A yellow waxy solid was obtained.Leaching with toluene, suction filtration, yellow filtrate, repeated several times until the solid pan white so far. The combined filtrates,The solvent was evaporated under reduced pressure to give 10.9 g of the crude product in a yield of 65.9%.
51%	With pyridine; thionyl chloride at 75℃; for 0.166667h; Cooling with ice;

	With iron(III) chloride at 180℃; Einleiten von Chlor;
	With pyridine; thionyl chloride at 75℃; for 2.66h; Cooling with ice;	1 Synthesis of 2,3-dichloromaleic anhydride A dry 250 mL round bottom flask was charged with 9.8 g (0.1 mol) of maleic anhydride, 100 mL (1.38 mol) of thionyl chloride was added under ice-cooling, and the magnetic stirring was carried out uniformly. 16.6 mL of pyridine was added dropwise with a constant pressure dropping funnel 0.2 mol), 1 h drop finished.After the dropwise addition, the mixture was stirred for 1 h under ice-cooling.Remove the ice bath, oil bath heated to 75 , reflux 40min.The residual thionyl chloride was distilled off under reduced pressure to give a yellow waxy solid.With toluene to leach, filter, the yellow filtrate, repeated several times until the solid white so far.The filtrates were combined and the solvent was evaporated under reduced pressure to give 10.9 g of crude product, yield 65.9%
	With pyridine; thionyl chloride at 75℃; for 1.66667h; Cooling with ice;	1 (1) Synthesis of 2,3-dichloromaleic anhydride In a dry 250 mL round bottom flask, 9.8 g (0.1 mol) of maleic anhydride was added,100 mL (1.38 mol) of dichlorosulfoxide was added and the magnetic stirring was carried out. 16.6 mL (0.2 mol) of pyridine was added dropwise with a constant pressure dropping funnel and the dropping was completed. After the dropwise addition, the mixture was stirred for 1 h under ice-cooling.Remove the ice bath, oil bath heated to 75 , reflux 40 min. The residual thionyl chloride was distilled off under reduced pressure,A yellow waxy solid was obtained. With toluene for leaching, filtration, the yellow filtrate,Repeated several times until the solid whitening. The filtrate was combined and the solvent was distilled off under reduced pressure to obtain a crude product of 10.9 g,Yield 65.9%.
	With pyridine; thionyl chloride at 75℃; for 1.66667h; Cooling with ice;	1 (1) Synthesis of 2,3-dichloromaleic anhydride In a dry 250-mL round-bottomed flask, 9.8 g (0.1 mol) of maleic anhydride was added, and 100 mL (1.38 mol) of thionyl chloride was added under ice-cooling. The mixture was stirred magnetically and pyridine (16.6 mL) was added dropwise using a constant-pressure dropping funnel. 0.2mol), 1h added dropwise.After the addition was complete, stirring was continued for 1 h under ice bath conditions.The ice bath was removed and the oil bath was heated to 75[deg.] C. and refluxed for 40 minutes.The residual thionyl chloride was distilled off under reduced pressure to give a yellow waxy solid.Leaching with toluene, suction filtration, the yellow filtrate was obtained, repeated several times until the solid whitening.The filtrates were combined, and the solvent was distilled off under reduced pressure to obtain 10.9 g of a crude product with a yield of 65.9%.
	With pyridine; thionyl chloride at 70 - 80℃; for 4h;	1.1; 2.1; 3.1; 4.1; 5.1; 6.1; 7.1 This embodiment adopts the process flow shown in FIG. 1, which specifically includes the following processes: (1) Feed thionyl chloride 2 and maleic anhydride 1 into the chlorination reaction unit I in a molar ratio of 8:1.The three-dimensional molar ratio of the total amount of recycled pyridine 4 and fresh pyridine 5 recovered by the pyridine recovery unit II to maleic anhydride is 1.5:1, the reaction temperature is 7080, and the chlorination reaction takes place under normal pressure. The reaction time is 4h, 2. The yield of 3-dichloromaleic anhydride was 85%.The chlorination reaction output 3 enters the pyridine recovery unit II, and the pyridine hydrochloride is filtered out first,Subsequently, pyridine hydrochloride reacts with diethylamine. The amount of base is 1.5 times the molar amount of pyridine hydrochloride. The reaction is carried out at 40°C for 2 hours and separated by ordinary distillation. The recovery rate of pyridine is 94%.

Reference： [1]Neumeyer, Markus; Brückner, Reinhard [Angewandte Chemie - International Edition, 2017, vol. 56, # 12, p. 3383 - 3388][Angew. Chem., 2017, vol. 129, # 12, p. 3432 - 3437,6]
[2]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN104710412, 2017, B Location in patent: Paragraph 0033; 0034; 0035; 0036; 0037
[3]Wang, Xiao; Zhao, Zhiyuan; Ai, Na; Pei, Jian; Liu, Yunqi; Wan, Xiaobo [European Journal of Organic Chemistry, 2016, vol. 2016, # 15, p. 2603 - 2607]
[4]Reppe et al. [Justus Liebigs Annalen der Chemie, 1955, vol. 596, p. 65]
[5]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN106432250, 2017, A Location in patent: Paragraph 0045; 0046; 0047; 0048; 0049
[6]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN104496970, 2017, B Location in patent: Paragraph 0037; 0038; 0039; 0040; 0041
[7]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN106478643, 2017, A Location in patent: Paragraph 0045; 0046; 0047; 0048; 0049
[8]Current Patent Assignee: CHINA CHEMICAL SCIENCE AND TECH RESEARCH - CN113527241, 2021, A Location in patent: Paragraph 0084-0092; 0108-0111; 0117-0120; 0126-0129; ...

2
[ 1122-17-4 ]
[ 57-13-6 ]
[ 1193-54-0 ]

Reference： [1]American Chemical Journal,1896,vol. 18,p. 336
[2]American Chemical Journal,1896,vol. 18,p. 336

3
[ 1122-17-4 ]
[ 150-78-7 ]
[ 14918-69-5 ]

Yield	Reaction Conditions	Operation in experiment
99%	Stage #1: dichloromaleic acid anhydride; 1,4-dimethoxybezene With aluminum (III) chloride; sodium chloride In neat (no solvent) at 140 - 175℃; for 0.0833333h; Stage #2: With hydrogenchloride; water at 20℃;
97%	Stage #1: dichloromaleic acid anhydride; 1,4-dimethoxybezene With aluminum (III) chloride; sodium chloride In neat (no solvent) at 180℃; for 0.0333333h; Stage #2: With hydrogenchloride; water
95%	With aluminum (III) chloride; sodium chloride at 150 - 170℃; for 0.166667h; Inert atmosphere;

93.4%	With aluminium trichloride; sodium chloride at 170 - 175℃; for 0.0833333h;
93%	With aluminum (III) chloride; sodium chloride at 175 - 180℃; for 0.05h;	Cycloacylation of Diether 11 by Anhydride 12. A melt of anhydrous AlCl3 (33.8 g, 0.253 mol) and dry NaCl(6.7 g, 0.114 mol) was stirred vigorously at 150°C and treated in portions with a mixture of dichloromaleic anhydride (9.5 g,0.057 mol) and hydroquinone dimethyl ether (3.95 g, 0.028 mol) that was ground beforehand in a mortar. The reactionmixture was placed into a metal bath heated to 175-180°C, stirred for 3 min, cooled to room temperature, treated with conc.HCl (24 mL) in H2O (360 mL), and left for 12 h. The precipitated product was separated, rinsed with hot (60°C) H2O(15 100 mL) until the filtrate was no longer colored, and dried to constant mass in a vacuum desiccator over CaCl2 to afford6.89 g (93%) of 13.
81%	With aluminium trichloride; sodium chloride at 170 - 175℃;
52%	With aluminum (III) chloride; sodium chloride at 145 - 180℃; for 0.0333333h;	1 2.2.1 Synthesis of 2,3-dichloro-5,8-dihydroxynaphthalene-1,4-dione (3) The mixture of p-dimethoxybenzene 1 (2.50 g, 18.1 mmol) and dichloromaleic anhydride 2 (6.05 g, 36.2 mmol) was added portionwise to the mixture of AlCl3 (21.35 g, 160.2 mmol) and NaCl (4.25 g, 72.6 mmol) which was melted by heating to 145 °C. After the reaction mixture was further heated to 180 °C and stirred for 2 min, the dark red melt was allowed to cool to room temperature. The mixture was hydrolyzed with water (227.5 mL) and concentrated HCl (15 mL) overnight. The pure red precipitate of 3 was collected by filtration (52% yield). 1H and 13C NMR spectral data of the isolated product matched with those reported in previous papers [ 34 ].
	With aluminium trichloride; sodium chloride at 180℃;
	With aluminium trichloride; sodium chloride at 140 - 150℃;
	With aluminium trichloride; sodium chloride
	With aluminium trichloride; sodium chloride at 180℃;
	Stage #1: dichloromaleic acid anhydride; 1,4-dimethoxybezene With aluminum (III) chloride; sodium chloride Stage #2: With hydrogenchloride; water at 145 - 185℃;

Reference： [1]Badolato, Mariateresa; Carullo, Gabriele; Caroleo, Maria Cristina; Cione, Erika; Aiello, Francesca; Manetti, Fabrizio [ACS Medicinal Chemistry Letters, 2019, vol. 10, # 4, p. 402 - 406]
[2]Guerrero-Vasquez, Guillermo A.; Andrade, Carlos Kleber Z.; Molinillo, Jose M. G.; MacIas, Francisco A. [European Journal of Organic Chemistry, 2013, # 27, p. 6175 - 6180]
[3]Neumeyer, Markus; Brückner, Reinhard [Angewandte Chemie - International Edition, 2017, vol. 56, # 12, p. 3383 - 3388][Angew. Chem., 2017, vol. 129, # 12, p. 3432 - 3437,6]
[4]Chang, He-Xi; Chou, Ting-Chao; Savaraj, Niramol; Liu, Leroy F.; Yu, Chiang; Cheng [Journal of Medicinal Chemistry, 1999, vol. 42, # 3, p. 405 - 408]
[5]Balaneva; Shestak; Anufriev; Novikov [Chemistry of Natural Compounds, 2016, vol. 52, # 2, p. 213 - 217][Khim. Prir. Soedin., 2016, # 2, p. 187 - 191]
[6]Huang, Li-Jiau; Chang, Fu-Chaio; Lee, Kuo-Hsiung; Wang, Jih-Pyang; Teng, Che-Ming; Kuo, Sheng-Chu [Bioorganic and Medicinal Chemistry, 1998, vol. 6, # 12, p. 2261 - 2269]
[7]Bao, Xia-Zhen; Wang, Qi; Ren, Xiao-Rong; Dai, Fang; Zhou, Bo [Free Radical Biology and Medicine, 2020, vol. 152, p. 597 - 608]
[8]Huot,R.; Brassard,P. [Canadian Journal of Chemistry, 1974, vol. 52, p. 838 - 842]
[9]Huot,R.; Brassard,P. [Canadian Journal of Chemistry, 1974, vol. 52, p. 838 - 842]
[10]Kawasaki, Motoji; Matsuda, Fuyuhiko; Terashima, Shiro [Tetrahedron, 1988, vol. 44, # 18, p. 5713 - 5726]
[11]Lewis, John R.; Paul, John G. [Journal of the Chemical Society. Perkin transactions I, 1981, p. 770 - 775]
[12]Zhao, Ai-Hong; Xu, De-Feng; Zhuo, Wen; Rao, Zhen; Li, Shao-Shun [Journal of Chemical Research, 2007, # 11, p. 647 - 648]
[13]Sánchez-Calvo, Juan M.; Barbero, Gara R.; Guerrero-Vásquez, Guillermo; Durán, Alexandra G.; Macías, Mariola; Rodríguez-Iglesias, Manuel A.; Molinillo, José M. G.; Macías, Francisco A. [Medicinal Chemistry Research, 2016, vol. 25, # 6, p. 1274 - 1285]

4
[ 1122-17-4 ]
[ 6641-32-3 ]

Yield	Reaction Conditions	Operation in experiment
90%	With hydrazine dihydrochloride; In water; for 0.5h;Heating / reflux;	To a round bottom flask was added water (170 ml) and hydrazine dihydrochloride salt (41.9 gm, 398.8 mmol). The solution was brought to reflux and dichloromandelic anhydride (66.6 gm, 398.9 mmol) was added portionwise. The reaction was stirred at reflux for 30 min. After this time, the solution was cooled to rt and the solid was collected by filtration to give the title compound, 4,5-dichloro-1,2-dihydropyridazine-3,6-dione (65 gm, 90% yield) as a white solid. MS(M+H)=181.0.

Reference： [1]Patent: US2006/287323,2006,A1 .Location in patent: Page/Page column 7
[2]Zhurnal Obshchei Khimii,1954,vol. 24,p. 1216,1219; engl. Ausg. S. 1205, 1206

5
[ 1122-17-4 ]
[ 571-60-8 ]
[ 29525-00-6 ]

Yield	Reaction Conditions	Operation in experiment
56%	With aluminium trichloride; sodium chloride In melt at 130℃; for 0.0166667h;

Reference： [1]Hall, Robert C.; Paul, Iain C.; Curtin, David Y. [Journal of the American Chemical Society, 1988, vol. 110, # 9, p. 2848 - 2854]

6
[ 1122-17-4 ]
[ 38442-51-2 ]
[ 30078-72-9 ]

Yield	Reaction Conditions	Operation in experiment
98%	With iodide In dimethyl sulfoxide at 40 - 45℃; Irradiation;

Reference： [1]Russell, Glen A.; Guo, Deliang; Baik, Woonphil; Herron [Heterocycles, 1989, vol. 28, # 1, p. 143 - 146]

7
[ 1122-17-4 ]
[ 2538-61-6 ]
[ 132370-86-6 ]

Reference： [1]Collection of Czechoslovak Chemical Communications,1990,vol. 55,p. 2707 - 2714

8
[ 1122-17-4 ]
[ 62-53-3 ]
[ 3876-05-9 ]

Yield	Reaction Conditions	Operation in experiment
80%	In acetic acid at 85 - 108℃; for 2h;
77%	In acetic acid for 2h; Heating;
75%	With acetic acid Reflux;

73.5%	With acetic acid
70%	In acetic acid Heating;
60%	In diethyl ether
	In acetic acid Heating; Shapiro method;
	With acetic acid for 2h; Heating;
	Stage #1: dichloromaleic acid anhydride; aniline In diethyl ether Heating; Stage #2: With sodium acetate; acetic anhydride at 95℃; for 4h;
	In acetic acid for 2h; Reflux;	3,4-Dichloro maleic anhydride 4, prepared from 2-butynedioic acid and thionyl chloride, was transformed into compounds 5a-f by treatment with appropriate arylamine in glacial acetic acid under reflux for 2h, according to the approach in Ref 16, 17.
	With acetic acid for 6h; Inert atmosphere; Schlenk technique; Reflux;

Reference： [1]Location in patent: experimental part Nagiev [Russian Journal of Organic Chemistry, 2012, vol. 48, # 3, p. 469 - 472]
[2]Andricopulo; Wlllain-Filho; Correa; Santos; Nunes; Yunes; Cechinel-Filho; Toker, Guelnur [Pharmazie, 1998, vol. 53, # 7, p. 493 - 494]
[3]Xu, Wen-Lei; Tang, Lei; Ge, Chen-Yu; Chen, Jie; Zhou, Ling [Advanced Synthesis and Catalysis, 2019, vol. 361, # 10, p. 2268 - 2273]
[4]Fan, Yongxian; Lu, Yuele; Chen, Xiaolong; Tekwani, Babu; Li, Xing-Cong; Shen, Yinchu [Molecules, 2018, vol. 23, # 11]
[5]Walter, Maria Elena; Mora, Cristiano; Mundstock, Karoline; De Souza, Marcia Ma; De Oliveira Pinheiro, Andreia; Yunes, Rosendo Augusto; Nunes, Ricardo J. [Archiv der Pharmazie, 2004, vol. 337, # 4, p. 201 - 206]
[6]Bodige, Satish G.; Mendez-Rojas, Miguel A.; Watson, William H. [Journal of Chemical Crystallography, 1999, vol. 29, # 1, p. 57 - 66]
[7]Luu-Duc; Marsura; Charlon; et al. [Farmaco, Edizione Scientifica, 1985, vol. 40, # 4, p. 253 - 258]
[8]Lopez, Silvia N.; Castelli, Maria V.; De Campos, Fatima; Correa, Rogerio; Cechinel Filho, Valdir; Yunes, Rosendo A.; Zamora, Miguel A.; Enriz, Ricardo D.; Ribas, Juan C.; Furlan, Ricardo L. E.; Zacchino, Susana A. [Arzneimittel-Forschung/Drug Research, 2005, vol. 55, # 2, p. 123 - 132]
[9]Mao, Yingqun; Maley, Iain; Watson, William H. [Journal of Chemical Crystallography, 2005, vol. 35, # 5, p. 385 - 403]
[10]Lin, Yuchen; Chen, Jing [Letters in drug design and discovery, 2013, vol. 10, # 5, p. 382 - 389]
[11]Wang, Yingxia; Eichhöfer, Andreas; Weigend, Florian; Fenske, Dieter; Fuhr, Olaf [Dalton Transactions, 2019, vol. 48, # 20, p. 6863 - 6871]

9
[ 1122-17-4 ]
[ 17154-34-6 ]
[ 51501-24-7 ]

Yield	Reaction Conditions	Operation in experiment
93%	In diethyl ether at 0℃; for 1h;

Reference： [1]Mao, Fei; Tyler, David R.; Keszler, Doug [Journal of the American Chemical Society, 1989, vol. 111, # 1, p. 130 - 134]

10
[ 1122-17-4 ]
[ 1193-54-0 ]

Yield	Reaction Conditions	Operation in experiment
	With ammonia; In acetic acid; at 108℃; for 1.5h;	General procedure: To suspension of 16.7 g (0.1 mol) of dichloromaleic anhydride in 60 g of glacial acetic acid was added dropwise 0.1 mol of the corresponding amine. The mixture was stirred for 30 min at 85 and for 90 min at 108. Then the mixture was cooled while stirred to 10, the precipitate was filtered off, washed with water, and dried in a vacuum at 60.

Reference： [1]Molecules,2018,vol. 23
[2]European Journal of Organic Chemistry,2016,vol. 2016,p. 2603 - 2607
[3]Chemistry - A European Journal,2014,vol. 20,p. 15226 - 15232
[4]Journal of the Chemical Society. Perkin transactions I,1984,p. 1165 - 1172
[5]Russian Journal of Organic Chemistry,2012,vol. 48,p. 469 - 472
[6]Journal of Agricultural and Food Chemistry,1996,vol. 44,p. 256 - 263
[7]Russian Journal of Organic Chemistry,2015,vol. 51,p. 1183 - 1186
Zh. Org. Khim.,2015,vol. 51,p. 1202 - 1205,4

11
[ 59660-63-8 ]
[ 1122-17-4 ]
[ 2949-92-0 ]
[ 75-18-3 ]
[ 1618-26-4 ]

Reference： [1]Journal of Organic Chemistry USSR (English Translation),1982,vol. 18,p. 2258 - 2260
Zhurnal Organicheskoi Khimii,1982,vol. 18,p. 2558 - 2561

12
[ 1122-17-4 ]
[ 100-66-3 ]
3-chloro-4-(phenoxymethyl)furan-2,5-dione [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
61%	With 2,2'-azobis(isobutyronitrile) In toluene at 70 - 75℃; for 30h;	3-Chloro-4-(phenoxymethyl)furan-2,5-dione(10b) 3,4-Dichloro-furan-2,5-dione3 (1.5g, 9.0 mmol), anisole (10mL) and AIBN (150 mg, 0.9 mmol) were heated at 70-75 °C for 6 h. A secondportion of AIBN (200 mg, 1.2 mmol) was added and the reaction continued for afurther 24 hours. Volatile components were removed under reduced pressure (80°Cat 15 mmHg) to leave a yellow residue. A sample of the pure product wasisolated first by chromatography on silica gel eluting with dichloromethane.This gave a pale yellow wax, which was redissolved in dichloromethane (2 mL).Addition of this solution to ether (50 mL) precipitated a solid which wasrecrystallised from ether to give the furan-2,5-dione 10b as a colourless solid (300 mg, 14%), TLC Rf = 0.9; mp 104-106 °C; Found: C, 55.37; H, 2.88. C11H7ClO4 requires C,55.37; H, 2.96%; 13CNMR (67.9 MHz; CDCl3) δ: 59.2 (OCH2), 114.8(x2)(C-2’/6’), 122.6 (C-4’), 129.9 (x2)(C3’/5’), 137.9 (C-4), 139.8 (C-3),157.4 (C-1’), 159.3 (C=O) and 161.4 (C=O); 1H NMR (270 MHz; CDCl3)δ: 4.95 (s, 2H, OCH2), 6.93 (d, JHH = 8.7 Hz, 2H,2’/6’-H), 7.04 (t, JHH = 8.7 Hz, 1H, 4’-H) and 7.32 (t, JHH = 8.7 Hz, 2H,3’/5’-H); IR (film, cm-1) ν: 1780, 1650, 1498, 1454, 1259, 1101, 1038, 940 and 737.
	With calcium carbonate; dibenzoyl peroxide In benzene at 80℃; for 5h; Yield given;

Reference： [1]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]
[2]Araneo, Silvia; Arrigoni, Riccardo; Bjorsvik, Hans-Rene; Fontana, Francesca; Liguori, Lucia; Minisci, Francesco; Recupero, Francesco [Tetrahedron Letters, 1996, vol. 37, # 38, p. 6897 - 6900]

13
[ 1122-17-4 ]
[ 108-88-3 ]
2-benzyl-3-chloromaleic anhydride [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
63%	With di-tert-butyl peroxide for 2h; Heating;
61%	With 2,2'-azobis(isobutyronitrile) In toluene at 100℃; for 24h;	3-Benzyl-4-chlorofuran-2,5-dione (10a) Thiscompound was prepared using a modification of the method outlined by Araneo et al.2 A solution of 3,4-dichlorofuran-2,5-dione3 3 (2.1g, 12.5 mmol) and AIBN (0.1 g, 0.6 mmol) in toluene (10 mL)was heated at 100 °C. After 4 h a second portion of AIBN (0.1 g, 0.6 mmol) wasadded, followed by a third portion of AIBN (0.1 g, 0.6 mmol) after a further 4h. The final mixture was then heated at 100 °C for 16 h. Volatile componentswere removed under reduced pressure (50 °C at 10 mmHg) to give a yellow oil whichwas purified by chromatography on silica gel eluting with dichloromethane. 3-Benzyl-4-chlorofuran-2,5-dione 10a (1.70 g, 61%) was initially isolated as an oil, but after storing at -35°C for 16 h it solidified to give a yellow waxwhich was recrystallised from hexane to give a colourless solid, TLC Rf = 0.9; mp 58-59 °C; Found: C, 59.64; H, 2.99. C11H7ClO3 requires C, 59.35; H, 3.17%; 13C NMR (67.9 MHz; CDCl3) δ: 30.3 (CH2), 127.7(C-4’), 129.1 (4 C, s, C-2’/3’/5’/6’), 133.8 (C-1’), 135.8 (C-4), 142.3 (C-3),159.8 (C=O) and 162.6 (C=O); 1H NMR (270 MHz; CDCl3) δ: 3.84 (s, 2H, CH2) and 7.26-7.33 (m,5H, Ar-H); IR (film, cm-1) ν: 3089, 3064, 3032, 1866,1783, 1646, 1619, 1496, 1455, 1433, 1249, 1205, 1079, 1038, 1007 and 923.
	With tert-Butyl peroxybenzoate; calcium carbonate at 110℃; for 2h; Yield given;

Reference： [1]Messorosh, Artyom V.; Trukhin, Alexey V.; Eliseenkov, Evgenii V. [Tetrahedron, 2008, vol. 64, # 48, p. 10849 - 10852]
[2]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]
[3]Araneo, Silvia; Arrigoni, Riccardo; Bjorsvik, Hans-Rene; Fontana, Francesca; Liguori, Lucia; Minisci, Francesco; Recupero, Francesco [Tetrahedron Letters, 1996, vol. 37, # 38, p. 6897 - 6900]

14
[ 1122-17-4 ]
[ 106-49-0 ]
[ 29244-55-1 ]

Yield	Reaction Conditions	Operation in experiment
90%	In acetic acid for 2h; Heating;
79.5%	With acetic acid
71%	In toluene for 4h; Reflux;

71%	In toluene for 4h; Reflux;
70%	In acetic acid at 85 - 108℃; for 2h;
	With acetic acid at 80℃; for 1h;

Reference： [1]Andricopulo; Wlllain-Filho; Correa; Santos; Nunes; Yunes; Cechinel-Filho; Toker, Guelnur [Pharmazie, 1998, vol. 53, # 7, p. 493 - 494]
[2]Fan, Yongxian; Lu, Yuele; Chen, Xiaolong; Tekwani, Babu; Li, Xing-Cong; Shen, Yinchu [Molecules, 2018, vol. 23, # 11]
[3]Imoto, Hiroaki; Kizaki, Kohei; Watase, Seiji; Matsukawa, Kimihiro; Naka, Kensuke [Chemistry - A European Journal, 2015, vol. 21, # 34, p. 12105 - 12111]
[4]Imoto, Hiroaki; Fujii, Ryosuke; Naka, Kensuke [European Journal of Organic Chemistry, 2018, vol. 2018, # 6, p. 837 - 843]
[5]Location in patent: experimental part Nagiev [Russian Journal of Organic Chemistry, 2012, vol. 48, # 3, p. 469 - 472]
[6]Cashman, John R.; MacDonald, Mary; Ghirmai, Senait; Okolotowicz, Karl J.; Sergienko, Eduard; Brown, Brock; Garcia, Xochella; Zhai, Dayong; Dahl, Russell; Reed, John C. [Bioorganic and Medicinal Chemistry Letters, 2010, vol. 20, # 22, p. 6560 - 6564]

15
[ 1122-17-4 ]
[ 106-47-8 ]
[ 29236-09-7 ]

Yield	Reaction Conditions	Operation in experiment
83.5%	With acetic acid
78%	In acetic acid for 2h; Heating;
	With acetic acid for 2h; Heating;

In acetic acid for 2h; Reflux;

3,4-Dichloro maleic anhydride 4, prepared from 2-butynedioic acid and thionyl chloride, was transformed into compounds 5a-f by treatment with appropriate arylamine in glacial acetic acid under reflux for 2h, according to the approach in Ref 16, 17.

Reference： [1]Fan, Yongxian; Lu, Yuele; Chen, Xiaolong; Tekwani, Babu; Li, Xing-Cong; Shen, Yinchu [Molecules, 2018, vol. 23, # 11]
[2]Andricopulo; Wlllain-Filho; Correa; Santos; Nunes; Yunes; Cechinel-Filho; Toker, Guelnur [Pharmazie, 1998, vol. 53, # 7, p. 493 - 494]
[3]Lopez, Silvia N.; Castelli, Maria V.; De Campos, Fatima; Correa, Rogerio; Cechinel Filho, Valdir; Yunes, Rosendo A.; Zamora, Miguel A.; Enriz, Ricardo D.; Ribas, Juan C.; Furlan, Ricardo L. E.; Zacchino, Susana A. [Arzneimittel-Forschung/Drug Research, 2005, vol. 55, # 2, p. 123 - 132]
[4]Lin, Yuchen; Chen, Jing [Letters in drug design and discovery, 2013, vol. 10, # 5, p. 382 - 389]

16
[ 1122-17-4 ]
[ 104-94-9 ]
[ 34379-53-8 ]

Yield	Reaction Conditions	Operation in experiment
86%	In acetic acid for 2h; Heating;
77%	In acetic acid at 85 - 108℃; for 2h;
77%	In toluene for 4h; Reflux;

75%	With toluene-4-sulfonic acid In toluene at 110℃;
63%	Heating;
	With acetic acid for 2h; Heating;
	In acetic acid for 2h; Reflux;	3,4-Dichloro maleic anhydride 4, prepared from 2-butynedioic acid and thionyl chloride, was transformed into compounds 5a-f by treatment with appropriate arylamine in glacial acetic acid under reflux for 2h, according to the approach in Ref 16, 17.

Reference： [1]Andricopulo; Wlllain-Filho; Correa; Santos; Nunes; Yunes; Cechinel-Filho; Toker, Guelnur [Pharmazie, 1998, vol. 53, # 7, p. 493 - 494]
[2]Location in patent: experimental part Nagiev [Russian Journal of Organic Chemistry, 2012, vol. 48, # 3, p. 469 - 472]
[3]Imoto, Hiroaki; Kizaki, Kohei; Watase, Seiji; Matsukawa, Kimihiro; Naka, Kensuke [Chemistry - A European Journal, 2015, vol. 21, # 34, p. 12105 - 12111]
[4]Watson, William H.; Chen, Tao; Richmond, Michael G. [Journal of Chemical Crystallography, 2004, vol. 34, # 11, p. 765 - 771]
[5]Hanaineh-Abdelnour, Leila; Salameh, Badr A. [Heterocycles, 1999, vol. 51, # 12, p. 2931 - 2940]
[6]Lopez, Silvia N.; Castelli, Maria V.; De Campos, Fatima; Correa, Rogerio; Cechinel Filho, Valdir; Yunes, Rosendo A.; Zamora, Miguel A.; Enriz, Ricardo D.; Ribas, Juan C.; Furlan, Ricardo L. E.; Zacchino, Susana A. [Arzneimittel-Forschung/Drug Research, 2005, vol. 55, # 2, p. 123 - 132]
[7]Lin, Yuchen; Chen, Jing [Letters in drug design and discovery, 2013, vol. 10, # 5, p. 382 - 389]

17
[ 1122-17-4 ]
[ 100-01-6 ]
[ 29236-11-1 ]

Yield	Reaction Conditions	Operation in experiment
92%	In acetic acid at 85 - 108℃; for 2h;
52%	Heating;
16%	In toluene for 4h; Reflux;

	Stage #1: dichloromaleic acid anhydride; 4-nitro-aniline In diethyl ether Heating; Stage #2: With sodium acetate; acetic anhydride at 95℃; for 4h;
	With acetic acid at 80℃; for 1h;
	In acetic acid for 2h; Reflux;	3,4-Dichloro maleic anhydride 4, prepared from 2-butynedioic acid and thionyl chloride, was transformed into compounds 5a-f by treatment with appropriate arylamine in glacial acetic acid under reflux for 2h, according to the approach in Ref 16, 17.

Reference： [1]Location in patent: experimental part Nagiev [Russian Journal of Organic Chemistry, 2012, vol. 48, # 3, p. 469 - 472]
[2]Hanaineh-Abdelnour, Leila; Salameh, Badr A. [Heterocycles, 1999, vol. 51, # 12, p. 2931 - 2940]
[3]Imoto, Hiroaki; Kizaki, Kohei; Watase, Seiji; Matsukawa, Kimihiro; Naka, Kensuke [Chemistry - A European Journal, 2015, vol. 21, # 34, p. 12105 - 12111]
[4]Mao, Yingqun; Maley, Iain; Watson, William H. [Journal of Chemical Crystallography, 2005, vol. 35, # 5, p. 385 - 403]
[5]Cashman, John R.; MacDonald, Mary; Ghirmai, Senait; Okolotowicz, Karl J.; Sergienko, Eduard; Brown, Brock; Garcia, Xochella; Zhai, Dayong; Dahl, Russell; Reed, John C. [Bioorganic and Medicinal Chemistry Letters, 2010, vol. 20, # 22, p. 6560 - 6564]
[6]Lin, Yuchen; Chen, Jing [Letters in drug design and discovery, 2013, vol. 10, # 5, p. 382 - 389]

18
[ 1122-17-4 ]
[ 1199-08-2 ]
[ 610311-09-6 ]

Yield	Reaction Conditions	Operation in experiment
88%	With aluminium trichloride; sodium chloride at 190℃; for 0.05h;
88%	Stage #1: dichloromaleic acid anhydride; ethylhydroquinone dimethyl ether With aluminium trichloride; sodium chloride at 195℃; for 0.0833333h; Stage #2: With hydrogenchloride In water for 12h; Further stages.;

Reference： [1]Glazunov; Yakubovskaya; Pokhilo; Bochinskaya; Anufriev [Russian Chemical Bulletin, 2003, vol. 52, # 1, p. 198 - 207]
[2]Yakubovskaya; Pokhilo; Mishchenko; Anufriev [Russian Chemical Bulletin, 2007, vol. 56, # 4, p. 819 - 822]

19
[ 1122-17-4 ]
[ 100-46-9 ]
[ 16114-24-2 ]

Yield	Reaction Conditions	Operation in experiment
90%	With acetic acid at 140℃; for 1.5h;
85%	In acetic acid at 100℃; for 1h;
81%	With acetic acid at 50℃; for 16h;

81%	With acetic acid at 50℃; for 16h;
77%	In acetic acid at 55℃; for 16h; Inert atmosphere;
68.3%	With acetic acid at 100℃; for 22h;	3,4-dichloro-N-benzylmaleimide Dichloromaleic anhydride (4.17 g, 25 mmol) was dissolved in acetic acid (25 ml) with slow addition of benzylamine (2.67 g, 25 mmol); the solution was heated at 100 °C for 22 h. After removal of solvent, the crude residue was separated by column chromatography on silica gel (hexane/ethyl acetate = 15:1) to give the product (4.37 g, 68.3%).
68.3%	With acetic acid Heating;
68.3%	With acetic acid at 100℃; for 22h;	3,4-dichloro-N-benzylmaleimide (Compound 1) Dichloromaleic anhydride (4.17 g, 25 mmol) was dissolved in acetic acid (25 mL) with slow addition of benzylamine (2.67 g, 25 mmol). The solution was heated at 100 °C for 22 h. After removal of the solvent, the crude residue was separated by column chromatography on silica gel (hexane/ethyl acetate = 15 : 1) to give the compound 1 (4.37 g, 68.3 %). 1H NMR (600 MHz, Chloroform-d) δ 7.40-7.32 (m, 5H), 4.75 (s, 2H). 13C NMR (151 MHz, CDCl3) δ 162.7, 135.1, 133.4, 128.9, 128.7, 128.4, 42.9.3
55.2%	With acetic acid at 50℃; for 16h;
	With acetic acid for 2h; Heating;
	With acetic acid at 50℃; Inert atmosphere;

Reference： [1]Botes, Delbert S.; Khorasani, Sanaz; Duminy, Welni; Levendis, Demetrius C.; Fernandes, Manuel A. [Crystal Growth and Design, 2020, vol. 20, # 1, p. 291 - 299]
[2]Holz, Jens; Zayas, Odalys; Jiao, Haijun; Baumann, Wolfgang; Spannenberg, Anke; Monsees, Axel; Riermeier, Thomas H.; Almena, Juan; Kadyrov, Renat; Boerner, Armin [Chemistry - A European Journal, 2006, vol. 12, # 19, p. 5001 - 5013]
[3]Stewart, Scott G.; Polomska, Marta E.; Lim, Rou Wei [Tetrahedron Letters, 2007, vol. 48, # 13, p. 2241 - 2244]
[4]Location in patent: scheme or table Xie, Hui-Ding; Ho, Louisa A.; Truelove, Michael S.; Corry, Ben; Stewart, Scott G. [Journal of Fluorescence, 2010, vol. 20, # 5, p. 1077 - 1085]
[5]Mosquera, ngeles; Frnandez, M. Isabel; Lopez, Moiss Canle; Sestelo, Jos Prez; Sarandeses, Luis A. [Chemistry - A European Journal, 2014, vol. 20, # 44, p. 14524 - 14530]
[6]Li, Baojun; Duan, Bing; Li, Jing; Zhang, Mengsi; Yuan, Yuan; Ding, Yun; Hu, Aiguo [Tetrahedron, 2018, vol. 74, # 44, p. 6419 - 6425]
[7]Li, Baojun; Zhang, Mengsi; Lu, Haotian; Ma, Hailong; Wang, Yue; Chen, Huimin; Ding, Yun; Hu, Aiguo [Chemistry - An Asian Journal, 2019, vol. 14, # 23, p. 4352 - 4357]
[8]Chen, Huimin; Ding, Yun; Hu, Aiguo; Li, Baojun; Lu, Haotian; Wang, Wenbo; Wang, Yue; Zhang, Mengsi [Tetrahedron, 2020]
[9]Li, Jing; Wu, Yuequn; Sun, Lili; Huang, Shuai; Li, Baojun; Ding, Yun; Hu, Aiguo [Chinese Journal of Chemistry, 2019, vol. 37, # 5, p. 479 - 485]
[10]Lopez, Silvia N.; Castelli, Maria V.; De Campos, Fatima; Correa, Rogerio; Cechinel Filho, Valdir; Yunes, Rosendo A.; Zamora, Miguel A.; Enriz, Ricardo D.; Ribas, Juan C.; Furlan, Ricardo L. E.; Zacchino, Susana A. [Arzneimittel-Forschung/Drug Research, 2005, vol. 55, # 2, p. 123 - 132]
[11]Bouissane, Latifa; Sestelo, Jose Perez; Sarandeses, Luis A. [Organic Letters, 2009, vol. 11, # 6, p. 1285 - 1288]

20
[ 1122-17-4 ]
[ 20781-20-8 ]
[ 342416-30-2 ]

Yield	Reaction Conditions	Operation in experiment
87%	With acetic acid; at 80℃; for 18h;	Example 6 12,13-(2-methoxycarbonyl-but-2-en-1,4-yl)-12,13-dihydro-5,7-dioxo-6H-indolo[2,3-a]pyrrolo[3,4-c]carbazole (Compound 3) 12,13-(2-methoxycarbonyl-2,3-dihydroxy-butan-1,4-yl)-12,13-dihydro-5,7-dioxo-6H-indolo[2,3-a]pyrrolo[3,4-c]carbazole (Compound 12) 12,13-(2-carboxy-2,3-dihydroxy-butan-1,4-yl)-12,13-dihydro-5,7-dioxo-6H-indolo[2,3-a]pyrrolo[3,4-c]carbazole (Compound 13) 12,13-{2-[(pyridin-4-ylmethyl)carbamoyl]-2,3-dihydroxy-butan-1,4-yl}-12,13-dihydro-5,7-dioxo-6H-indolo[2,3-a]pyrrolo[3,4-c]carbazole (Compound 117) 3,4-dichloro-furan-2,5-dione (6.7 g, 40 mmol) was mixed with 2,4-dimethoxy-benzylamine (6.25 mL) in glacial acetic acid (120 mL). The mixture was heated to 80 C. for 18 hrs. Upon cooling, the mixture was poured over ice and the precipitate was collected by filtration, then washed with water and NaHCO3 (aq.) and dried in a vacuum oven to provide 3,4-dichloro-1-(2,4-dimethoxy-benzyl)-pyrrole-2,5-dione Compound 6a (11.08 g, 87%) as a light orange solid. 1H NMR (d6-DMSO, 300 MHz) delta 3.73 (s, 3H), 3.76 (s, 3H), 4.54 (s, 2H), 6.44 (d, 1H, J=8 Hz), 6.57 (s, 1H), 7.12 (d, H, J=8 Hz); MS m/z 340 (M+2+Na), 338 (M+Na), 318 (M+2H), 316 (M+H).

Reference： [1]Bioorganic and Medicinal Chemistry Letters,2009,vol. 19,p. 3333 - 3338
[2]Patent: US2007/249590,2007,A1 .Location in patent: Page/Page column 73; 74
[3]Tetrahedron Letters,2007,vol. 48,p. 7399 - 7403
[4]Bioorganic and Medicinal Chemistry,2004,vol. 12,p. 1239 - 1255

21
[ 1122-17-4 ]
[ 5042-30-8 ]
4,5-dichloro-1-(2,2,2-trifluoroethyl)-1,2-dihydro-pyridazine-3,6-dione [ No CAS ]

Reference： [1]Synthetic Communications,2006,vol. 36,p. 2719 - 2726

22
[ 1122-17-4 ]
[ 371-40-4 ]
[ 41205-21-4 ]

Yield	Reaction Conditions	Operation in experiment
99.2%	In water;	EXAMPLE 4 10g (0.06 mol) of 2,3-dichloromaleic anhydride was dissolved in 200 ml of water. Then to the resulting solution 5.55g (0.05 mol) of 4-fluoroaniline was added dropwise over a period of 5 min. at room temperature under agitation. The mixture was then allowed to react for 2 hours at reflux temperatures. Upon cooling the reaction mixture, precipitated crystal was separated by filtration to obtain 12.9g of N-(4-fluorophenyl)-2,3-dichloromaleimide melting at 240-243 C (not corrected) at a yield of 99.2%. An anaylsis by gas chromatography showed the product had a purity of 99.3%.
99.1%	In water;	EXAMPLE 5 5.55g (0.05 mol) of 4-fluoroaniline was emulsified in 150 ml of water. Then to the resulting emulsion 10g (0.06 mol) of 2,3-dichloromaleic anhydride in 50 ml of water was added dropwise over a period of 30 min. at room temperatures under agitation. The mixture was then allowed to react at reflux temperatures. Upon cooling the reaction mixture, a crystal was removed out, which was separated by filtration to obtain 12.9g of N-(4-fluorophenyl)-2,3-dichloromaleimide melting at 240-243 C (not corrected) at a yield of 99.1%. An analysis by gas chromatography showed the product had a purity of 98.6%.
98.4%	In water;	EXAMPLE 2 10g (0.06 mol) of 2,3-dichloromaleic anhydride was dissolved in 100 ml of water. Then, to the resulting solution 5.55g (0.05mol) of 4-fluoroaniline was added dropwise over a period of 5 min. at room temperatures under agitation. The mixture was allowed to react for 2 hours at 80 C. Upon cooling the reaction mixture, a crystal was separated out, which was then separated by filtration to obtain 12.8g of N-(4-fluorophenyl)-2,3-dichloromaleimide melting at 239-242 C (not corrected) at a yield of 98.4%. An analysis by gas chromatography showed the product had a purity of 98.7%.

91.5%

In water;

EXAMPLE 3 10g (0.06 mol) of 2,3-dichloromaleic anhydride was dissolved in 100 ml of water. Then to the resulting solution 5.55g (0.05 mol) of 4-fluoroaniline was added dropwise over a period of 5 min. at room temperatures under agitation. The mixture was then allowed to react for 15 hours at 60 C. Upon cooling the reaction mixture, precipitated crystal was separated by filtration to obtain 11.9g of N-(4-fluorophenyl)-2,3-dichloromaleimide melting at 239-242 C (not corrected) at a yield of 91.5%. An analysis by gas chromatography showed the product had a purity of 97.9%.

Reference： [1]Patent: US4010182,1977,A
[2]Patent: US4010182,1977,A
[3]Patent: US4010182,1977,A
[4]Patent: US4010182,1977,A
[5]Molecules,2018,vol. 23
[6]Journal of Chemical Crystallography,2005,vol. 35,p. 385 - 403

23
(S,S)-2,5-trans-diphenylphospholane [ No CAS ]
[ 1122-17-4 ]
3,4-bis[(S,S)-2,5-diphenylphospholan-1-yl]-furan-2,5-dione [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	With triethylamine In tetrahydrofuran at 60℃; for 18h;	4 (-?,iS)-l-hydroxy-l-oxo-2,5-frα/J5-diphenylphospholane (600 mg, 2.20 mmol) was suspended in toluene (6 ml). The mixture was degassed by evacuation and filling with nitrogen (*5) and then heated in an oil bath at 110 0C (external temperature). Phenylsilane (0.54 ml, 4.41 mmol) was added in one portion and the mixture was heated for 2h (during this time vigorous effervescence is observed and a clear solution forms). The solution was cooled to room temperature and the solvent was evaporated under reduced pressure. The crude phosphine was further dried under high vacuum (2.9 mbar, 60 0C). The residue was cooled to room temperature and dissolved in THF (3 ml) under nitrogen. Triethylamine (0.31 ml, 2.20 mmol) was added, followed by a solution of 2,3-dichloromaleic anhydride (167 mg, 1.00 mmol) in THF (2 ml). The mixture was heated in an oil bath at 60 0C (external temperature) and stirred for 18 h (dark purple solution forms). The solution was cooled to room temperature and solvent was evaporated under reduced pressure. The residue was chromatographed on silica, eluting with DCM/heptane (2:3) to give a deep red oil which solidified on standing (180 mg, 0.31 mmol, 31%).1H NMR (400 MHz, CDCl3) 5 ppm 7.51-7.34 (10 H, m), 6.90 (4 H, d, JS Hz), 6.80 (2 H, t, J 7 Hz), 6.56 (4 H, t, J 8 Hz), 4.60-4.53 (2 H, m), 4.05-3.93 (2 H, m), 2.73-2.61 (2 H. m), 2.58-2.45 (2 H. m), 2.44-2.35 (2 H, m) and 1.97-1.85 (2 H, m).13C NMR (100 MHz, CDCl3) δ ppm 161.7, 156.2 (m), 141.1 (t, J 11 Hz), 136.6, 127.1, 127.0, 126.9, 126.8, 125.0, 124.9, 124.7, 48.2 {,J l Hz), 41.1 (d, J5 Hz), 38.0 and 31.6.31P NMR (162 MHz, CDCl3) δppm 3.5.
180 mg	With triethylamine In tetrahydrofuran at 60℃; for 18h;

Reference： [1]Current Patent Assignee: DR REDDY'S LABORATORIES LIMITED; DOW INC - WO2007/123957, 2007, A2 Location in patent: Page/Page column 17; 18
[2]Fox, Martin E.; Jackson, Mark; Lennon, Ian C.; Klosin, Jerzy; Abboud, Khalil A. [Journal of Organic Chemistry, 2008, vol. 73, # 3, p. 775 - 784]

24
[ 1122-17-4 ]
[ 109-73-9 ]
[ 20198-79-2 ]

Yield	Reaction Conditions	Operation in experiment
94%	With acetic acid at 20℃; for 4.5h; Reflux;	N-n-Butyl-2,3-dichloromaleimide (1) n-Butylamine (148 µL, 1.50mmol) was added to a solutionof dichloromaleic anhydride (250 mg, 1.50 mmol) in acetic acid (1.00mL) and the mixture was stirred at room temperaturefor 30min, and then refluxed for 4h. After cooling to roomtemperature, the mixture was added saturated aq. NaHCO3. The whole was extracted with AcOEt. The combined organiclayer was dried over Na2SO4and concentrated. The residue was purified by flash silica-gel chromatography (AcOEt-nhexane=1 : 20) to afford 1(313 mg, 1.41 mmol, 94%) as a colorless oil. 1: 1H-NMR (CDCl3) δ: 0.86 (3H, t, J=7.4 Hz), 1.25 (2H, tq, J=7.4, 7.4 Hz), 1.53 (2H, tt, J=7.5, 7.5 Hz), 3.53 (2H, t, J=7.2 Hz). 13C-NMR (CDCl3) δ: 13.6, 20.0, 30.6, 39.3, 133.3, 163.2. HR-MS (electrospray ionization (ESI))m/z: 276.0170 (Calcd for C8H9Cl2NO2(M+MeOH+Na+): 276.0170).
82.5%	With acetic acid
75%	In acetic acid at 100℃; for 1h;

Reference： [1]Chiba, Kosuke; Hashimoto, Yuichi; Yamaguchi, Takao [Chemical and Pharmaceutical Bulletin, 2016, vol. 64, # 11, p. 1647 - 1653]
[2]Fan, Yongxian; Lu, Yuele; Chen, Xiaolong; Tekwani, Babu; Li, Xing-Cong; Shen, Yinchu [Molecules, 2018, vol. 23, # 11]
[3]Holz, Jens; Zayas, Odalys; Jiao, Haijun; Baumann, Wolfgang; Spannenberg, Anke; Monsees, Axel; Riermeier, Thomas H.; Almena, Juan; Kadyrov, Renat; Boerner, Armin [Chemistry - A European Journal, 2006, vol. 12, # 19, p. 5001 - 5013]

25
[ 1122-17-4 ]
[ 2393-23-9 ]
[ 64697-66-1 ]

Yield	Reaction Conditions	Operation in experiment
80.3%	Stage #1: dichloromaleic acid anhydride; 4-methoxy-benzylamine In acetic acid for 3h; Heating / reflux; Acidic conditions; Stage #2: In acetic acid at 20℃;	1.b lb) p-Methoxybenzyl amine (75.3 g, 549 mmol) was added dropwise to a stirred solution of dichloromaleic anhydride (91.6 g, 549 mmol) in ACOH (850 mL) at room temperature. The solution was refluxed for 3 hours and left overnight at room temperature. The precipitate was filtered and washed with ACOH (2x100 mL) and ice-cold ETOH (2x100 mL) to give after drying in vacuo the pure title compound (76.4 g). The filtrate was concentrated to 300 mL and cooled to-5°C for 4 hours to give a second crop of pure title compound (49.5 g, total yield 80. 3 %). IH-NMR (300 MHz, DMSO-d6) : 6 3.61 (3H, s, OCH3--H Harom), 7.20 (2H, d, Harom). MS (ESI) m/z 286 [M+H] +.

Reference： [1]Current Patent Assignee: N A D - WO2004/48384, 2004, A1 Location in patent: Page 17

26
[ 1122-17-4 ]
[ 866025-84-5 ]
[ 505092-86-4 ]

Yield	Reaction Conditions	Operation in experiment
87%	In diethyl ether at 0 - 20℃; for 0.75h;	4 4.71g of (2R,5R)-2, 5-dimethyl-l-trimethylsilylphospholane(dissolved in 5 ml of ether) are added at 0°C to a solution of 2.09 g of dichloromaleic anhydride in 20 ml of ether and the mixture is stirred at this temperature for a further 15 minutes. After a further 30 minutes at room temperature, the solution is cooled to -78°C. The product crystallizes as brown crystals. The crystals are filtered off and dried under reduced pressure.Yield: 3.56 g; 87%1H-NMR (CDC13):8 = 1.06 (dd, 6H), 1.22 (dd, 6H), 2.49-1.25 (m, 12H) , 3.32 (m, 2H) ppm. 31P-NMR (CDC13):8 = -2.2 ppm.

Reference： [1]Current Patent Assignee: EVONIK INDUSTRIES AG - WO2005/49629, 2005, A1 Location in patent: Page/Page column 14-15

27
[ 1122-17-4 ]
[ 1123-61-1 ]

Yield	Reaction Conditions	Operation in experiment
	With methylamine hydrochloride; sodium methylate; acetic acid In water	12 PREPARATION 12: PREPARATION 12: Dichloro-N-methylmaleimide A 3L-three-necked flask fitted with a magnetic stir bar, digital thermocouple/thermometer, nitrogen purge and solid addition funnel was charged with 450 g (269.5 mol) of dichloromaleic anhydride, 191 g (282.8 mol) of methylamine hydrochloride and 1.6 L of acetic acid. The reaction mixture was then cooled to 10° C., and 160 g NaOMe added from the solid addition funnel over 1 hour while keeping the temperature between 10°-12° C. The reaction mixture was allowed to stir at room temperature for 42 hours (24 hours is sufficient) then heated to 100° C. for 3 hours. HPLC analysis at this time indicated that all the starting material had disappeared. The reaction was cooled to room temperature and 2L water was added. The mixture was then cooled to 3°-10° C. for 1 hour and filtered at 4° C. The solids were then rinsed with 2L of cold deionized water. The pale yellow solid dried in an air oven overnight to afford 360 g (75%) yield of the titled compound.

Reference： [1]Current Patent Assignee: ELI LILLY & CO - US5859261, 1999, A

28
[ 96-02-6 ]
[ 1122-17-4 ]
[ 92-84-2 ]
[ 126-99-8 ]
[ 118-45-6 ]

Yield	Reaction Conditions	Operation in experiment
		EXAMPLE 4 This example shows that the entire sequence of cycloaddition, elimination and aromatization can be carried out in a single vessel with a good yield of 4-chlorophthalic anhydride. A 3-necked 50 mL flask was equipped with a pressure equalizing addition funnel, a thermocouple well with thermocouple, a water cooled condensor and a magnetic stir bar. The flask was charged with 13.2 g (0.10 mol) of a 90/10 GC area % mixture of monochloromaleic anhydride and dichloromaleic anhydride and 100 mg of phenothiazine and 0.5 g of activated carbon. The contents of the flask were heated to 80 to 130 C. and 8.8 g (0.1 mol) of chloroprene was added over 15 to 30 minutes. HCl gas was observed evolving from the reactor. After 6 hours at 130 C. the contents of the flask were sparged with oxygen for 2 hours between 130 and 150 C., filtered hot, and multiple distilled into two fractions resulting in the isolation of 13.2 g (80% of theoretical) of 4-chlorophthalic anhydride.

Reference： [1]Patent: US5322954,1994,A

29
[ 1122-17-4 ]
[ 22236-04-0 ]
[ 82673-77-6 ]

Yield	Reaction Conditions	Operation in experiment
90%	In 1,4-dioxane; water	1 Preparation of 2,3-dichloro-N-(o-difluoromethoxyphenyl)maleimide EXAMPLE 1 Preparation of 2,3-dichloro-N-(o-difluoromethoxyphenyl)maleimide 16.7 g (0.1 mole) of 2,3-dichloromaleic anhydride is dissolved in 100 ml of dioxane, and a solution of 15.9 g (0.1 mole) of o-difluoromethoxyaniline in 30 ml of dioxane is added dropwise to it at room temperature over 20 minutes with stirring. Thereafter, the resulting solution is stirred at 70°-80° C. for 2 hours and the dioxane is then distilled off under a reduced pressure. Water is added to the residue to precipitate crystals. The precipitated crystals are filtered off and recrystallized from ethanol to give 27.7 g (yield: 90%) of 2,3-dichloro-N-(o-difluoromethoxyphenyl)maleimide melting at 103.5°-104° C. in the form of light yellow crystals.

Reference： [1]Current Patent Assignee: IDEMITSU KOSAN CO LTD - US4455315, 1984, A

30
[ 1122-17-4 ]
[ 22236-08-4 ]
[ 82673-78-7 ]

Yield	Reaction Conditions	Operation in experiment
95%	In 1,4-dioxane; water;	EXAMPLE 2 Preparation of 2,3-dichloro-N-(m-difluoromethoxyphenyl)maleimide 16.7 g (0.1 mole) of 2,3-dichloromaleic anhydride is dissolved in 100 ml of dioxane, and a solution of 15.9 g (0.1 mole) of <strong>[22236-08-4]m-difluoromethoxyaniline</strong> in 30 ml of dioxane is added dropwise to it at room temperature over 20 minutes with stirring. Thereafter, the resulting solution is stirred at 70-80 C. for 2 hours and the dioxane is then distilled off under a reduced pressure. Water is added to the residue to precipitate crystals. The precipitated crystals are filtered off and recrystallized to give 29.2 g (yield: 95%) of 2,3-dichloro-N-(m-difluoromethoxyphenyl)maleimide melting at 122-124 C. in the form of light yellow plate crystals.

Reference： [1]Patent: US4455315,1984,A

31
[ 1122-17-4 ]
[ 22236-10-8 ]
3,4-dichloro-1-[4-(difluoromethoxy)-phenyl]-1H-pyrrole-2,5-dione [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	In toluene;	EXAMPLE 3 Preparation of 2,3-dichloro-N-(p-difluoromethoxyphenyl)maleimide A solution of 16.7 g (0.1 mole) of 2,3-dichloromaleic anhydride in 70 ml of toluene is heated to boiling. A solution of 15.9 g (0.1 mole) of p-difluoromethoxyaniline in 30 ml of toluene is added dropwise to it over 20 minutes with stirring. Thereafter, the resulting solution is refluxed until water is no longer distilled. This requires about 2 hours. The mixture is cooled to room temperature to precipitate crystals. The precipitated crystals are filtered off and washed with hexane to obtain 29.2 g of 2,3-dichloro-N-(p-difluoromethoxyphenyl)maleimide melting at 217.5-218 C. in the form of light yellow plate crystals.

Reference： [1]Patent: US4455315,1984,A

32
[ 1122-17-4 ]
[ 371-40-4 ]
4-fluoroanilinium 2,3-dichloromaleate [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
92%	In water	10 EXAMPLE 10 EXAMPLE 10 8.35g (0.05 mol) of 2,3-dichloromaleic anhydride was dissolved in 20 ml of water. To the resulting solution an emulsion prepared from 5.55g (0.05 mol) of 4-fluoroaniline and 10 ml of water was added dropwise over a period of 30 min. After completing the additon, the reaction mixture was stand for 10 min. and precipitated crystal was separated by filtration to obtain 13.6g of 4-fluoroanilinium 2,3-dichloromaleate at a yield of 92%. The salt was identical with that produced in Example 7 and had a melting point (decomposition point) of 207° C.

Reference： [1]Current Patent Assignee: MITSUBISHI CHEMICAL HOLDINGS CORPORATION; Mitsubishi Chemical Corp (in: MCHC Group) - US4010182, 1977, A

33
[ 1122-17-4 ]
[ 108-39-4 ]
[ 107-06-2 ]
[ 68096-18-4 ]

Yield	Reaction Conditions	Operation in experiment
	With hydrogenchloride; sodium hydroxide In water	1 EXAMPLE 1 The starting material can be prepared, for example, as follows. 250 ml of 1,2-dichloroethane and 265 g of powdered anhydrous aluminium chloride are initially introduced into a stirred flask provided with a hydrogen chloride outlet. Subsequently, in the course of about 30 minutes, with stirring, 54 g of 3-methyl-phenol and then, in the course of 1.5 hours, 87.5 g of 2,3-dichloromaleic anhydride (95% pure) are added at 20°-30°. After stirring for a further 4 hours at room temperature (about 20°-25°) the reaction mixture is discharged into a mixture of 250 ml of concentrated hydrochloric acid, water and ice; end volume about 3,000 ml. The dichloroethane solution is separated off, 500 ml of water are added and the organic solvent is removed under reduced pressure in a rotary evaporator at a heating bath temperature of about 50°. The residue is dissolved in 3,000 ml of water with the addition of 200 ml of a 30% strength solution of sodium hydroxide in water, the solution is stirred for 10 minutes at 20°-25° and is then clarified by filtration, using a silica gel filter aid. The reaction product is precipitated from the filtrate at 0°-5° by adding excess hydrochloric acid and is filtered off and washed with a little water. After drying at 60° and under reduced pressure, reddish-tinged yellow 2-carboxychloromethylene-6-methyl-coumaranone is obtained and after recrystallisation from ethyl acetate this melts at 172°-174°.

Reference： [1]Current Patent Assignee: Novartis (w/o Sandoz); NOVARTIS AG - US4185110, 1980, A

34
[ 1122-17-4 ]
[ 536-89-0 ]
[ 1035452-24-4 ]

Yield	Reaction Conditions	Operation in experiment
40%	With hydrogenchloride In water at 100℃; for 3h;	2 Preparation of 4,5-Dichloro-l-(3-methylphenyl)-1,2-dihydropyridazin -3,6-dione (19a).; 3,4-Dichloromaleic anhydride (18a) (2.0 g, 12.27 mmol) was added to a solution 3-methylphenylhydrazine (5) (1.5 g, 12.27 mmol) in 20% aqueous HCl (12 mL) at 100 °C and stirred for 3 h. The reaction mixture was cooled to room temperature and diluted with water (15 mL) and extracted with ethyl acetate (3x 20 mL). The combined extracts was dried, and concentrated in vacuo to afford a residue that was purified on silica gel column (20% EtOAc/hexaness) to afford (19a) (1.35 g, 40 %). 1HNMR (300 MHz, DMSO-D6): δ 2.36 (s, 3H), 7.22-7.25 (m, IH), 7.33-7.41 (m, 3H); ESI-MS m/z. 271.2 (M+l)+.

Reference： [1]Current Patent Assignee: MEMORIAL SLOAN-KETTERING CANCER CENTER - WO2008/80056, 2008, A2 Location in patent: Page/Page column 98

35
[ 120-72-9 ]
[ 1122-17-4 ]
[ 174574-69-7 ]

Yield	Reaction Conditions	Operation in experiment
95%	Stage #1: indole With ethylmagnesium bromide In tetrahydrofuran; diethyl ether at 40℃; for 0.25h; Stage #2: dichloromaleic acid anhydride In tetrahydrofuran; diethyl ether at 20℃; for 2.5h;

Reference： [1]Delarue-Cochin, Sandrine; McCort-Tranchepain, Isabelle [Organic and Biomolecular Chemistry, 2009, vol. 7, # 4, p. 706 - 716]

36
[ 1122-17-4 ]
[ 52031-15-9 ]
[ 1133458-18-0 ]

Reference： [1]Organic and Biomolecular Chemistry,2009,vol. 7,p. 706 - 716

37
[ 1122-17-4 ]
[ 593-51-1 ]
[ 1123-61-1 ]

Yield	Reaction Conditions	Operation in experiment
75%	Stage #1: dichloromaleic acid anhydride; methylamine hydrochloride With acetic acid Stage #2: With sodium methylate at 20℃; Reflux;
73%	With potassium acetate; acetic acid at 110℃; for 4h;	Step 1 General procedure: Methylamine hydrochloride (19.1 g, 0.30 moles) was added to a solution of acetic acid (40 ml), maleic anhydride (20 g, 0.20 moles) and potassium acetate (30.0 g, 0.30 moles) and the mass was stirred for 4 hrs at reflux temperature (110 oC). After completion of reaction, the mass was cooled to 25 - 30 oC. The reaction mass was poured, slowly, on to the chilled sodium bicarbonate solution (100 ml) and the product was extracted with diethylether (3 x 70 ml). The organic layer was washed with brine solution, dried over anhydrous sodium sulfate and solvent was removed under reduced pressure to afford 1-methyl pyrrole-2,5-dione (6.89 g, 30 %).
68%	With potassium acetate; acetic acid for 4h; Reflux;

68%	With potassium acetate In acetic acid for 4h; Reflux;
7.3 g	With acetic acid for 6h; Reflux;	2 Synthesis of 2,3-dichloro-N-methylmaleimide To the 250 mL round bottom flask was added 10.9 g (65.9 mmol) of 2,3-dichloromaleic anhydride and 4.42 g (65.9 mmol) of methylamine hydrochloride, 100 mL of glacial acetic acid was added and the magnetic stirring was carried out under reflux for 6 h. TLC To complete reaction.The solution was dark brown. After cooling to room temperature, 100 mL of water was added, extracted with ethyl acetate, washed with saturated sodium bicarbonate solution and saturated brine in that order, and the solvent was evaporated under reduced pressure to give a crude brown product. Column chromatography (volume ratio Ether: ethyl acetate = 9: 1, silica gel 200-300 mesh) to give 7.3 g of a white flake solid in 62% yield.
7.3 g	With acetic acid for 6h; Reflux;	2 (2) Synthesis of 2,3-dichloro-N-methylmaleimide. To a 250 mL round bottom flask was added 25.9 mmol (65.9 mmol) of 2,3-dichloromaleic anhydride andMethylamine hydrochloride 4.42 g (65.9 mmol), 100 mL of glacial acetic acid was added and the magnetic stirring was carried out under reflux for 6 h. TLC was tracked to complete reaction. Solution dark brown, down to room temperature, add water 100 mL,Extracted with ethyl acetate, washed with saturated sodium bicarbonate solution and saturated brine in this order,The solvent was evaporated under reduced pressure to give a crude brown product which was separated by column chromatography (petroleum ether: ethyl acetate = 9: 1,Silica gel 200-300 mesh) to give a white flake solid of 7.3 g in 62% yield.
7.3 g	With acetic acid for 6h; Reflux;	2 (2) Synthesis of 2,3-dichloro-N-methylmaleimide. A 250 mL round bottom flask was charged with 10.9 g (65.9 mmol) of 2,3-dichloromaleic anhydride,And 4.42 g (65.9 mmol) of methylamine hydrochloride,Add glacial acetic acid 100mL,Under reflux conditions magnetic stirring 6h,TLC trace detection until the reaction is complete.The solution was dark brown and then cooled to room temperature. Water (100 mL) was extracted with ethyl acetate, washed with saturated sodium bicarbonate solution and brine, and the solvent was distilled off under reduced pressure to obtain a crude brown product. The residue was separated by column chromatography (petroleum ether: Ethyl ester = 9: 1,Silica gel 200-300 mesh) to obtain a white flaky solid 7.3g, yield 62%.

Reference： [1]Delarue-Cochin, Sandrine; McCort-Tranchepain, Isabelle [Organic and Biomolecular Chemistry, 2009, vol. 7, # 4, p. 706 - 716]
[2]Nirogi, Ramakrishna; Dwarampudi, Adireddy; Kambhampati, Ramasastry; Bhatta, Venugopalarao; Kota, Laxman; Shinde, Anil; Badange, Rajesh; Jayarajan, Pradeep; Bhyrapuneni, Gopinadh; Dubey [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 15, p. 4577 - 4580]
[3]Xie, Yujie; Husband, Jonathan T.; Torrent-Sucarrat, Miquel; Yang, Huan; Liu, Weisheng; O'Reilly, Rachel K. [Chemical Communications, 2018, vol. 54, # 27, p. 3339 - 3342]
[4]Lewin, Anita H.; Brieaddy, Larry; Deschamps, Jeffrey R.; Imler, Gregory H.; Mascarella, S. Wayne; Reddy, P. Anantha; Carroll, F. Ivy [ACS Chemical Neuroscience, 2019, vol. 10, # 1, p. 246 - 251]
[5]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN106432250, 2017, A Location in patent: Paragraph 0050; 0051; 0052; 0053; 0054
[6]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN104496970, 2017, B Location in patent: Paragraph 0042; 0043; 0044; 0045; 0046
[7]Current Patent Assignee: HENAN NORMAL UNIVERSITY - CN104710412, 2017, B Location in patent: Paragraph 0038; 0039; 0040; 0041; 0042

38
[ 19798-77-7 ]
[ 1122-17-4 ]
[ 1258283-37-2 ]

Reference： [1]Bioorganic and Medicinal Chemistry Letters,2010,vol. 20,p. 6560 - 6564

39
[ 1122-17-4 ]
[ 62-53-3 ]
[ 112080-62-3 ]

Yield	Reaction Conditions	Operation in experiment
	In chloroform at 20℃; for 1h;	4.1.1. Synthesis of maleimides General procedure: The synthesis of maleimides 1-47 was performed by mixing an equimolar amount of the appropriate maleic anhydrides 68-72 in 5 mL of CHCl3 and anilines 73, 78-90, amines 91-94 or phenylalkylamines 74-77 (5 mmol) dissolved in 1 mL of CHCl3 and stirred during 1 h. The solid (maleamic acid) which precipitated out of the reaction mixture was filtered off. The whole amount of maleamic acid was dissolved in 5 mL of acetic anhydride and 100 mg of sodium acetate was added. The mixture was heated for 2 h under reflux. The reaction was cooled and quenched with water; then, the aqueous solution was extracted with Et2O, dried with Na2SO4, filtered, and the solvent was evaporated. The product was purified by silica gel column chromatography using a mixture of hexane and ethyl acetate (9:1) as eluent. Compounds 1-10, 16-26, 31-34, 36, 38-42 and 43-47 were previously reported.[3], [8], [21], [22], [23], [24], [25], [26], [27] and [28]

Reference： [1]Location in patent: experimental part Sortino; Garibotto; Cechinel Filho; Gupta; Enriz; Zacchino [Bioorganic and Medicinal Chemistry, 2011, vol. 19, # 9, p. 2823 - 2834]

40
[ 1122-17-4 ]
[ 89990-53-4 ]
[ 1340546-95-3 ]

Yield	Reaction Conditions	Operation in experiment
	In water; at 20℃; for 13h;Reflux;	An amount of 8.907 g (56 mmol) of <strong>[89990-53-4]hexahydropyridazine dihydrochloride</strong> in 25 ml of water is admixed slowly with 9.349 g (56 mmol) of dichloromaleic anhydride. The mixture is stirred at room temperature for 1 hour and then under reflux for 12 hours. After the mixture has cooled, the crystals obtained are isolated by filtration with suction. This gives 11.87 g (99% purity, 89.3% of theory) of 2,3-dichloro-6,7,8,9-tetrahydropyridazino[1,2-a]pyridazine-1,4-dione.

Reference： [1]Patent: US2011/281877,2011,A1 .Location in patent: Page/Page column 12-13

41
[ 1122-17-4 ]
[ 593-56-6 ]
[ 99120-64-6 ]

Yield	Reaction Conditions	Operation in experiment
68%	With sodium ethanolate; acetic acid at 20℃; for 16h;	3.1 Step 1 : Preparation of 3.4-dichloro-1 -methoxy-pyrrole-2.5-dioneAt room temperature 3.6 g (52.9 mmol) sodium ethanolate were added to a mixture of 5.6 g (33.5 mmol) 2.3-dichloro maleic anhydride and 4.6 g (55.1 mmol) methoxyamine hydrochloride in 50 ml of acetic acid. The reaction mixture was stirred 16 hours at room temperature and then poured into an ice/water mixture. An insoluble solid crystalized out which was filtered off and washed with water. Then this solid was redissolved in ethyl acetate, the solution was dried over magnesium sulfate and evaporated. 4.5 g (68 % of theory) of the title compound were obtained as a light colored solid. 1H-NMR (CDCI3. δ in ppm):4.0 (s. 3H).

Reference： [1]Current Patent Assignee: BASF SE - WO2012/139987, 2012, A1 Location in patent: Page/Page column 43

42
[ 142-45-0 ]
[ 1122-17-4 ]

Yield	Reaction Conditions	Operation in experiment
	With thionyl chloride at 40℃; for 8h;	3,4-Dichloro maleic anhydride 4, prepared from 2-butynedioic acid and thionyl chloride, was transformed into compounds 5a-f by treatment with appropriate arylamine in glacial acetic acid under reflux for 2h, according to the approach in Ref 16, 17.

Reference： [1]Lin, Yuchen; Chen, Jing [Letters in drug design and discovery, 2013, vol. 10, # 5, p. 382 - 389]

43
[ 1122-17-4 ]
[ 121-45-9 ]
dimethyl 3-(dimethoxyphosphoryl)-2,5-dioxo-4-(trimethoxy-λ⁵-phosphoran-ylidene)tetrahydrofuran-3-ylphosphonate [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
77%	In dichloromethane at 20℃;	Typical Procedure for the Reactions of 3,4-dichlorofuran-2,5-dione14 (3)with the Trivalent Phosphorus Ester General procedure: A solution of the phosphorus ester RRPOR (40 mmol) in dichloromethane (5 mL)was added dropwise, over a period of ca. 5 min, to a stirred solution of 3,4-dichlorofuran-2,5-dione 3 (13 mmol) in dichloromethane (15 mL) at room temperature. After stirring themixture overnight, volatile components were removed in vacuo (40C at 0.005 mmHg) togive the corresponding ylide 18 in a good state of purity. If necessary the ylide 18 can bepurified by chromatography on silica gel using dichloromethane-acetonitrile mixtures asthe eluant

Reference： [1]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]

44
[ 1122-17-4 ]
[ 122-52-1 ]
diethyl 3-(diethoxyphosphoryl)-2,5-dioxo-4-(triethoxy-λ⁵-phosphoranylidene)-tetrahydrofuran-3-ylphosphonate [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
62%	In dichloromethane at 20℃;	Typical Procedure for the Reactions of 3,4-dichlorofuran-2,5-dione14 (3)with the Trivalent Phosphorus Ester General procedure: A solution of the phosphorus ester RRPOR (40 mmol) in dichloromethane (5 mL)was added dropwise, over a period of ca. 5 min, to a stirred solution of 3,4-dichlorofuran-2,5-dione 3 (13 mmol) in dichloromethane (15 mL) at room temperature. After stirring themixture overnight, volatile components were removed in vacuo (40C at 0.005 mmHg) togive the corresponding ylide 18 in a good state of purity. If necessary the ylide 18 can bepurified by chromatography on silica gel using dichloromethane-acetonitrile mixtures asthe eluant

Reference： [1]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]

45
[ 1122-17-4 ]
[ 116-17-6 ]
diisopropyl 3-(diisopropyloxyphosphoryl)-2,5-dioxo-4-(triisopropoxy-λ⁵-phosphoranylidene)tetrahydrofuran-3-ylphosphonate [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
53%	In dichloromethane at 20℃;	Typical Procedure for the Reactions of 3,4-dichlorofuran-2,5-dione14 (3)with the Trivalent Phosphorus Ester General procedure: A solution of the phosphorus ester RRPOR (40 mmol) in dichloromethane (5 mL)was added dropwise, over a period of ca. 5 min, to a stirred solution of 3,4-dichlorofuran-2,5-dione 3 (13 mmol) in dichloromethane (15 mL) at room temperature. After stirring themixture overnight, volatile components were removed in vacuo (40C at 0.005 mmHg) togive the corresponding ylide 18 in a good state of purity. If necessary the ylide 18 can bepurified by chromatography on silica gel using dichloromethane-acetonitrile mixtures asthe eluant

Reference： [1]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]

46
[ 2946-61-4 ]
[ 1122-17-4 ]
methyl [4-(dimethoxyphenyl-λ⁵-phosphanylidene)-3-(methoxyphenylphosphinoyl)-2,5-dioxo-tetrahydrofuran-3-yl](phenyl)phosphinate [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
35%	In dichloromethane at 20℃;	Typical Procedure for the Reactions of 3,4-dichlorofuran-2,5-dione14 (3)with the Trivalent Phosphorus Ester General procedure: A solution of the phosphorus ester RRPOR (40 mmol) in dichloromethane (5 mL)was added dropwise, over a period of ca. 5 min, to a stirred solution of 3,4-dichlorofuran-2,5-dione 3 (13 mmol) in dichloromethane (15 mL) at room temperature. After stirring themixture overnight, volatile components were removed in vacuo (40C at 0.005 mmHg) togive the corresponding ylide 18 in a good state of purity. If necessary the ylide 18 can bepurified by chromatography on silica gel using dichloromethane-acetonitrile mixtures asthe eluant

Reference： [1]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]

47
[ 1122-17-4 ]
[ 4020-99-9 ]
3,3-bis-(diphenylphosphinoyl)-4-(methoxydiphenyl-λ5-phosphanylidene)-dihydrofuran-2,5-dione [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
76%	In dichloromethane at 20℃;	Typical Procedure for the Reactions of 3,4-dichlorofuran-2,5-dione14 (3)with the Trivalent Phosphorus Ester General procedure: A solution of the phosphorus ester RRPOR (40 mmol) in dichloromethane (5 mL)was added dropwise, over a period of ca. 5 min, to a stirred solution of 3,4-dichlorofuran-2,5-dione 3 (13 mmol) in dichloromethane (15 mL) at room temperature. After stirring themixture overnight, volatile components were removed in vacuo (40C at 0.005 mmHg) togive the corresponding ylide 18 in a good state of purity. If necessary the ylide 18 can bepurified by chromatography on silica gel using dichloromethane-acetonitrile mixtures asthe eluant

Reference： [1]Vaughan Griffiths; Benoit, David M.; Cheong, Yuen-Ki; Duncanson, Philip; Han, Xiao [Phosphorus, Sulfur and Silicon and the Related Elements, 2014, vol. 189, p. 1013 - 1027]

48
[ 1122-17-4 ]
[ 33902-93-1 ]
3,4-dichloro-1-(hexadecan-6-yl)-1H-pyrrole-2,5-dione [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
69%	With acetic acid at 100℃; for 3h; Inert atmosphere;	2 In a dried 3 neck round bottom flask (11) 2,3-dichloromaleic anhydride (24g, 0.144mol)) was dissolved underargon atmosphere in 400ml of acetic acid. 6-hexadecylamine (36g, 0.149mol) was added and the reaction medium wasrefluxed during 3 hours. The solvent was removed under vacuum and the product was dissolved in 500ml of ethyl acetate.After washing with 200ml of HCL 0.1N, 200ml of NaOH 0.1N and 200ml of saturated NaCl solution, the organic layerwas dried over MgSO4. After removal of the solvent, 39g of the respective dichloromaleimide (3,4-dichloro-1-(hexadecan-6-yl)-1H-pyrrole-2,5-dione) was recovered with a yield of 69%. The product was used without further purification
69%	In acetic acid for 3h; Inert atmosphere; Reflux;	2 In a dried 3 neck round bottom flask (11) 2,3-dichloromaleic anhydride (24g, 0.144mo1) ) was dissolved under argon atmosphere in 400m1 of acetic acid. 6-hexadecylamine (36g, 0.149mo1) was added and the reaction medium was refluxed during 3 hours. The solvent was removed under vacuum and the product was dissolved in 500m1 of ethyl acetate. After washing with 200m1 of HCL 0.1 N, 200m1 of NaOH 0.1 N and 200m1 of saturated NaCI solution, the organic layer was dried over MgSO4. After removal of the solvent, 39g of the respective dichloromaleimide (3,4- dichloro-1-(hexadecan-6-yl)-1 H-pyrrole-2,5-dione) was recovered with a yield of 69%. The product was used without further purification

Reference： [1]Current Patent Assignee: SOLVAY - EP2808327, 2014, A1 Location in patent: Paragraph 0129; 0130
[2]Current Patent Assignee: SOLVAY - WO2014/191358, 2014, A1 Location in patent: Paragraph 00147; 00148

49
[ 1122-17-4 ]
[ 655-86-7 ]
7,11-dihydrofuropyrazino[2,3-b]phenazine-8,10-dione [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
61%	With hydrogenchloride In N,N-dimethyl-formamide for 10h; Reflux;	4.1.5.2. 7,11-Dihydrofuropyrazino[2,3-b]phenazine-8,10-dione 16 To a mixture of equimolar quantities of the 2,3-diaminophenazine 1 (4 mmol, 0.84) and dichloromaleic anhydride (4 mmol, 0.50 g) in DMF, hydrochloric acid (7 ml, 4 N) was added. The mixture was refluxed for 10 h. The reaction mixture was poured onto cold water, the precipitated solid was filtered off and recrystallized from ethanol-dioxane to give (0.52 g, 61%) brown crystals; m.p. 243-245 °C. IR (KBr, ν, cm-1): 3418 (2NH), 1652 (2C=O), 1598 (2C=N). MS m/z (%): 307 (M++ 17.19), 306 (M+, 4.58), 279 (27.79), 252 (23.50), 208 (13.75), 174 (21.78), 125 (20.63), 94 (100), 76 (2.58). 1HNMR (DMSO-d6, δ ppm): 7.13 (t, J = 10 Hz, 2H, Ar-H), 7.61 (d, J = 10 Hz, 2H, Ar-H), 7.62 (s, 2H, Ar-H), 13.38 (s, 2H, 2NH). Anal. Calcd. for C16H8N4O3 (304.25): C, 63.16; H, 2.65; N, 18.40. Found: C, 63.09; H, 2.59; N, 18.43%.

Reference： [1]Mahran, Asma M.; Ragab, Sherif Sh.; Hashem, Ahmed I.; Ali, Mamdouh M.; Nada, Afaf A. [European Journal of Medicinal Chemistry, 2015, vol. 90, p. 568 - 576]

50
[ 1122-17-4 ]
[ 108-91-8 ]
2,3-dichloro-N-cyclohexylmaleamic acid [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	In acetic acid at 85℃; for 0.5h;	N-Substituted imides of dichloromaleic acid General procedure: To suspension of 16.7 g (0.1 mol) of dichloromaleic anhydride in 60 g of glacial acetic acid was added dropwise 0.1 mol of the corresponding amine. The mixture was stirred for 30 min at 85° and for 90 min at 108°. Then the mixture was cooled while stirred to 10°, the precipitate was filtered off, washed with water, and dried in a vacuum at 60°.
	In ethyl acetate

Reference： [1]Nagiev, Ya. M. [Russian Journal of Organic Chemistry, 2015, vol. 51, # 8, p. 1183 - 1186][Zh. Org. Khim., 2015, vol. 51, # 8, p. 1202 - 1205,4]
[2]Onimura, Kenjiro; Yamabuki, Kazuhiro; Yang, Xiaodong [New Journal of Chemistry, 2022, vol. 46, # 3, p. 1232 - 1237]

51
[ 1122-17-4 ]
[ 63-74-1 ]
[ 65833-21-8 ]

Yield	Reaction Conditions	Operation in experiment
90%	With acetic acid at 20℃; Reflux;	General procedure for the synthesis of 3,4-dichloromaleimidosulfonamide The sulfonamide intermediate was prepared by the condensation of the sulfanilamide (2) and the dichloromaleic anhydride (1) in glacial acetic acid solution. The procedure used to prepare the 3,4-dichloromaleimido sulfonamide (3) consisted in the additionof 0.1 mol of the sulfanilamide (2) compound in 25-30 mL of glacial acetic acid to a solution of 0.1 mol of the dichloromaleic anhydride (1) in 50-75 mL of glacial acetic acid at room temperature. The temperature was gradually increased to reflux and the refluxing was continued for 15-30 min. Dilute the cooled reaction mixture with water to obtain the 3,4-dichloromaleimido sulfonamide.Yield (%): 90%; mp (C): >300 °C; IR (KBr, cm1): 3458(NH2), 3126 (Ar, CAH), 1734 (CO), 1594 (Ar CC), 1344, 1158(SO2); 1H NMR (400 MHz, DMSO-d6) ppm: 7.92 (d, J = 8.52 Hz,2H, Ar), 7.53 (d, J = 8.52, 2H, Ar), 7.36 (br s, 2H, NH2); 13C NMR(100 MHz, DMSO-d6) ppm: 161.6 (2; CO imide), 143.6 (2;CACl), 133.63 (SO2AC), 132.93 (CAN), 126.78, 126.57 (4C;Ar); m/z 319.2 [M+H]+.

Reference： [1]Firke, Sandip D.; Bari, Sanjay B. [Bioorganic and Medicinal Chemistry, 2015, vol. 23, # 17, p. 5273 - 5281]

52
[ 1122-17-4 ]
[ 147962-41-2 ]
N-(propyl)-3,4-dichloro-2,5-dioxopyrrole-1-sulfonamide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
83%	With Dawson acid; In acetonitrile; for 1h;Inert atmosphere; Reflux; Green chemistry;	General procedure: Under nitrogen atmosphere, a mixture of sulfonamide 2a-h (1 mmol), maleic anhydride derivatives (2 mmol), and H6P2W18O62 catalyst (2 mmol%) in acetonitrile (2 mL), was stirred at reflux. Reaction was monitored by TLC. After achieving the reaction, dichloromethane (2 ×10 mL) was added and the catalyst was filtered; water (10 mL) was then added. The organic layers were combined and dried over anhydrous sodium sulfate and removed under reduced pressure. The residue obtained was purified by flash chromatography (Merck silica gel 60H, CH2Cl2/MeOH, 9:1) to afford the corresponding sulfonyl maleimide derivatives.

Reference： [1]Phosphorus, Sulfur and Silicon and the Related Elements,2016,vol. 191,p. 1344 - 1350

53
[ 1122-17-4 ]
C₃H₉BrN₂O₂S [ No CAS ]
C₇H₇BrCl₂N₂O₄S [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
78%	With Dawson acid In acetonitrile for 1h; Inert atmosphere; Reflux; Green chemistry;	General procedure for the synthesis of N-sulfonyl maleimides(3a-3j and 4a-4j) General procedure: Under nitrogen atmosphere, a mixture of sulfonamide 2a-h (1 mmol), maleic anhydride derivatives (2 mmol), and H6P2W18O62 catalyst (2 mmol%) in acetonitrile (2 mL), was stirred at reflux. Reaction was monitored by TLC. After achieving the reaction, dichloromethane (2 ×10 mL) was added and the catalyst was filtered; water (10 mL) was then added. The organic layers were combined and dried over anhydrous sodium sulfate and removed under reduced pressure. The residue obtained was purified by flash chromatography (Merck silica gel 60H, CH2Cl2/MeOH, 9:1) to afford the corresponding sulfonyl maleimide derivatives..