Name: 996-98-5|Oxalyl dihydrazide|98%
Brand: Ambeed
SKU: A270444
Rating: 98 (25 reviews)

1
[ 996-98-5 ]
[ 118-93-4 ]
[ 5287-29-6 ]

Yield	Reaction Conditions	Operation in experiment
	With ethanol
	In methanol; water for 3h; Reflux;	Preparation of oxaloyldihydrazone ligands General procedure: In view of the importance of oxaloyldihydrazones and their chelates, we have undertaken the synthesis of four ligand structures including bis(salicylaldehyde)oxaloyldihydrazone (L1), bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (L2), bis(2-hydroxyacetophenone)oxaloyldihydrazone (L3), bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L4). Oxalicdihydrazide(0.01 mol) dissolved first in hot water (20 cm3) followed by adding methanol (40 cm3) was mixed with the appropriate aldehydes [salicylaldehyde, 2-hydroxy-1-naphthaldehyde,2-hydroxyacetophenone and 2-methoxybenzaldehyde](0.02 mol) in absolute methanol. The resulting mixture went onr efluxing for 3 hrs under constant stirring. The product was separated out on concentrating the solution to half of its volume and cooling. The crystals of the desired ligand was collected by filtration through a Buchner funnel and dried in an electricoven at 50° C for 2 h. Afterwards the ligand was recrystallizedfrom DMF-MeOHaq mixed solvent, collected, washed thoroughly on filter paper by acetone to remove any excess of DMF and then dried in an electric oven at 50 °C for 2 h. The molecular structure of the resulting hydrazones was elucidated by elemental analyses and spectral (IR, mass and 1H NMR)measurements (Table 2, 3).

Reference： [1]Sacconi [Journal of the Chemical Society, 1954, p. 1326]
[2]Ahmed, Ayman H.; Hassan; Mohamed, Bassem H.; Gumaa, Hosni A.; Eraky, Ahmed M. [Inorganic and Nano-Metal Chemistry, 2017, vol. 47, # 12, p. 1652 - 1663]

2
[ 996-98-5 ]
[ 90-02-8 ]
[ 5287-25-2 ]

Yield	Reaction Conditions	Operation in experiment
92%	In methanol for 10h; Reflux;	Synthesis of N'¹,N'⁴-bis(2-hydroxybenzylidene)oxalohydrazide (H₄L²) Solution of oxalohydrazide (236 mg, 0.2 mmol) and salicylaldehyde(488 mg, 0.4 mmol) in methanol (10 mL) was refluxed for10 h. A milky precipitate was formed which was filtered, washedwith methanol and dried at air. Yield: 92% (60 mg).
85%	In water at 20℃; for 4h;	2.2. Synthesis of the H4L pro-ligand Synthesis of the oxalyl dihydrazide was carried out from diethyl oxalate and hydrazine hydrate according to a literature method[44]. A modification was made in the preparation of the Schiff basewith salicylaldehyde. To an aqueous solution of 236 mg (2 mmol) of oxalyl dihydrazide, 488 mg salicylaldehyde (4 mmol) were added; the obtained suspension was stirred for about 4 h at room temperature.Within this time, a yellowish white precipitate of the Schiff base H4L appeared. This was filtered off, washed with ethanol andether and left for slow evaporation at r.t.
75.4%	In methanol at 20℃; for 72h; Acidic conditions;

65%	In ethanol for 2h; Reflux;	N'¹,N'²-bis(2-hydroxy-1-naphthylmethylene)oxalohydrazide (H4L1) General procedure: A mixture of oxalyl dihydrazide(1.50 g, 12.7 mmol) and 2-hydroxy-1-naphthaldehyde (4.80 g,25.4 mmol) in anhydrous ethanol solution (600 mL) was refluxedfor 2 h under constant stirring using magnetic stirrer. The productwas filtered and washed with ethanol, then dried in vacuo. The yellowpowder product was obtained. Yield: 48%.
	With ethanol
	In ethanol; water Heating;
	In ethanol for 1h; Reflux;
	In methanol; water for 3h; Reflux;	Preparation of oxaloyldihydrazone ligands General procedure: In view of the importance of oxaloyldihydrazones and their chelates, we have undertaken the synthesis of four ligand structures including bis(salicylaldehyde)oxaloyldihydrazone (L1), bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (L2), bis(2-hydroxyacetophenone)oxaloyldihydrazone (L3), bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L4). Oxalicdihydrazide(0.01 mol) dissolved first in hot water (20 cm3) followed by adding methanol (40 cm3) was mixed with the appropriate aldehydes [salicylaldehyde, 2-hydroxy-1-naphthaldehyde,2-hydroxyacetophenone and 2-methoxybenzaldehyde](0.02 mol) in absolute methanol. The resulting mixture went onr efluxing for 3 hrs under constant stirring. The product was separated out on concentrating the solution to half of its volume and cooling. The crystals of the desired ligand was collected by filtration through a Buchner funnel and dried in an electricoven at 50° C for 2 h. Afterwards the ligand was recrystallizedfrom DMF-MeOHaq mixed solvent, collected, washed thoroughly on filter paper by acetone to remove any excess of DMF and then dried in an electric oven at 50 °C for 2 h. The molecular structure of the resulting hydrazones was elucidated by elemental analyses and spectral (IR, mass and 1H NMR)measurements (Table 2, 3).
	In methanol at 100℃; for 2h;

Reference： [1]Hosseini-Monfared, Hassan; Asghari-Lalami, Nasim; Pazio, Aleksandra; Wozniak, Krzysztof; Janiak, Christoph [Inorganica Chimica Acta, 2013, vol. 406, p. 241 - 250]
[2]Gupta, Samik; Kirillova, Marina V.; Guedes Da Silva, M. Fátima; Pombeiro, Armando J.L. [Applied Catalysis A: General, 2013, vol. 460-461, p. 82 - 89]
[3]Jo, Tae Geun; Lee, Jae Jun; Nam, Eunju; Bok, Kwon Hee; Lim, Mi Hee; Kim, Cheal [New Journal of Chemistry, 2016, vol. 40, # 10, p. 8918 - 8927]
[4]Shi, Jingnan; Wei, Yi; Zhang, Yuzhen; Tang, Jie; Bian, Hedong; Yu, Qing; Huang, Fuping [Polyhedron, 2019, vol. 162, p. 81 - 90]
[5]Sacconi [Journal of the Chemical Society, 1954, p. 1326]
[6]Chandra, R.; Sahni, S. K.; Kapoor, R. N. [Acta Chimica Hungarica, 1983, vol. 112, # 4, p. 385 - 400]
[7]Location in patent: body text Zamani, Hassan Ali [Chinese Chemical Letters, 2011, vol. 22, # 6, p. 701 - 704]
[8]Ahmed, Ayman H.; Hassan; Mohamed, Bassem H.; Gumaa, Hosni A.; Eraky, Ahmed M. [Inorganic and Nano-Metal Chemistry, 2017, vol. 47, # 12, p. 1652 - 1663]
[9]Adam, Mohamed Shaker S.; Ahmed, Mohamed S. Mohamed; El-Hady, Omar M.; Shaaban, Saad [Applied Organometallic Chemistry, 2020, vol. 34, # 5]

3
[ 996-98-5 ]
[ 110-13-4 ]
N,N'-bis(2,5-dimethylpyrrol-1-yl)oxalamide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
85%	With acetic acid for 2h; Reflux;
54%	With acetic acid at 2℃; Reflux;	4.4. Synthesis of N,N'-bis(2,5-dimethylpyrrol-1-yl)oxalamide(L3) Hexane-2,5-dione (13.7 g, 0.12 mol) was added to a suspensionof oxalyl dihydrazide (11.8 g, 0.1 mol) in acetic acid (100 mL) ina 500 mL flask equipped with a reflux condenser. The reaction mixture was refluxed for 2 h, cooled to room temperature, and the formed precipitate was filtered off, washed with water, and dried at 100°C
	With acetic acid

Reference： [1]Ray, Ritwika; Hartwig, John F. [Angewandte Chemie - International Edition, 2021, vol. 60, # 15, p. 8203 - 8211][Angew. Chem., 2021, vol. 133, # 15, p. 8284 - 8292,9]
[2]Kurandina, Daria V.; Eliseenkov, Eugene V.; Ilyin, Petr V.; Boyarskiy, Vadim P. [Tetrahedron, 2014, vol. 70, # 26, p. 4043 - 4048]
[3]Buelow [Chemische Berichte, 1905, vol. 38, p. 3917]

4
[ 553-90-2 ]
[ 996-98-5 ]

Yield	Reaction Conditions	Operation in experiment
99.4%	With hydrazine hydrate In methanol at 80℃; for 0.000833333h;	8 Preparation of oxalyldihydrazide Dissolving dimethyl oxalate in methanol, Make a 3mol/L solution for use. 80% by mass of hydrazine hydrate is dissolved in methanol, A 3 mol/L solution was prepared for use. A methanol solution of dimethyl oxalate was injected into the microchannel reactor or the pipeline reactor through a metering pump at a flow rate of 25 ml/min. The hydrazine hydrated methanol solution was injected into the microchannel reactor or pipeline reactor through another metering pump at a flow rate of 25.5 ml/min. React at 80 ° C for 3 seconds, Flow out of the microchannel reactor or pipeline reactor, Collecting reaction materials, Obtaining a white crystalline product, The yield is 99.4%. The content is 99.7%, The monoterpene content is 0.01%. The reaction mother liquid methanol was filtered and applied.
95%	With hydrazine hydrate In methanol
75%	With hydrazine hydrate for 8h; Reflux;	Synthesis of oxalohydrazide A mixture of dimethyl oxalate (0.06 g, 0.05 mmol) and hydrazinehydrate (98%, 2 mL) in methanol was refluxed for 8 h. Thewhite precipitate of oxalohydrazide was filtered, washed withmethanol and dried in air. Yield: 75% (0.045 g).

With hydrazine hydrate In methanol

Reference： [1]Current Patent Assignee: WISPO NEW MAT SUZHOU - CN109574870, 2019, A Location in patent: Paragraph 0075-0077
[2]Wu, Dehua; Song, Jintong; Qu, Lang; Zhou, Weilan; Wang, Lei; Zhou, Xiangge; Xiang, Haifeng [Chemistry - An Asian Journal, 2020, vol. 15, # 20, p. 3370 - 3378]
[3]Hosseini-Monfared, Hassan; Asghari-Lalami, Nasim; Pazio, Aleksandra; Wozniak, Krzysztof; Janiak, Christoph [Inorganica Chimica Acta, 2013, vol. 406, p. 241 - 250]
[4]Volovel'skii,L.N.; Knorozova,G.V. [Journal of general chemistry of the USSR, 1964, vol. 34, p. 341 - 344][Zhurnal Obshchei Khimii, 1964, vol. 34, p. 343 - 347]

5
[ 95-92-1 ]
[ 996-98-5 ]

Yield	Reaction Conditions	Operation in experiment
98%	With hydrazine hydrate monohydrate In methanol at 60℃; for 8h;
97%	With hydrazine hydrate monohydrate In acetonitrile at 20℃; for 4h;	1.1 (1)oxalyldihydrazide (ODH) synthesis 6 mL of 80% by mass hydrazine hydrate was added to 100 mL of acetonitrile at room temperature,A solution of 7.31 g (0.05 mol) of diethyl oxalate was added dropwise,At room temperature for 4h, the reaction solution, the filter cake by ethanol leaching,Dried with oxalic hydrazide 5.73 g, yield 97%, purity 98%;
95%	With hydrazine hydrate monohydrate for 0.5h;	2.2. Preparation of disalicyaldehyde oxaloyldihydrazone Oxaloyldihydrazine was prepared by reacting diethyloxalate (20mL) and hydrazine hydrate (13mL) in 1:2M ratios under stirring for 30min. The product thus isolated was recrystallized from H2O. (Yield: 95%). Disalicylaldehyde oxaloyldihydrazone (H4slox) was prepared by condensing oxaloyldihydrazine (3g, 25.42mmol), in hot H2O (100mL) with salicylaldehyde (6.20mL) in ethanol (20mL) over hot plate at 70°C with constant stirring for 1h. The light yellow precipitate thus obtained was washed with hot H2O-ethanol, ethanol and finally with ether and dried over anhydrous CaCl2. (Yield: 93%)

90.5%	With hydrazine hydrate monohydrate In ethanol for 3h; Reflux;	1.1 (1) Preparation of oxalyl hydrazide 6.0 mmol of diethyl oxalate and 24.0 mmol of 80% hydrazine hydrate were placed in 16 mL of ethanol for 3 h.The reaction mixture was cooled to room temperature and suction filtered.The filter cake is washed with petroleum ether and ethanol and dried to obtain oxalyl hydrazide.White solid,M.p.240~241°C,The yield was 90.5%.
60%	With hydrazine hydrate monohydrate In methanol for 8h; Reflux;	25.1 Synthesis of oxalic acid dihydrazide (VII-1) Diethyl oxalate (VI-1) (0.65 g, 25 mmol) And hydrazine monohydrate (4.86 mL, 100 mmol)Was dissolved in 50 ml of methanol,And heated under reflux for 8 hours. MeTanol was distilled off under reduced pressure,The residue was triturated with ethanol,The separated solid was collected by filtration.1.77 g (yield: 60%) of a colorless dihydrazide compound (VII-1) was obtained.
	With hydrazine hydrate monohydrate In ethanol
	With hydrazine hydrate monohydrate Heating;
	With hydrazine hydrate monohydrate In ethanol at -15℃;
	With hydrazine hydrate monohydrate
	With hydrazine hydrate monohydrate
	With hydrazine monohydrate In ethanol
	With hydrazine monohydrate In ethanol	Preparation of oxaloyldihydrazine Ethanol solution of diethyl oxalate (1 mol) was added to hydrazine hydrate (2.5 mol) accompanied by vigorous stirring. This yielded white precipitate which was filtered and washed with ethanol. The precipitate was recrystallized from hot water and dried under ambient condition.
	With hydrazine hydrate monohydrate In ethanol
	With hydrazine monohydrate In methanol Reflux;
	With hydrazine hydrate monohydrate In water monomer Cooling with ice;	Preparation of spinel based oxides Synthesis of pure and copper incorporated spinels was carried out employing a single step solution combustion method in an open muffle furnace kept in a fume hood by the combustion of the corresponding metal nitrate salts with oxalyldihydrazide (C2H6N4O2(ODH)) as the fuel. Oxalyldihydrazide was prepared by the dropwise addition of diethyl oxalate (C2H6N4O2, Sisco Research Laboratories Pvt. Ltd., 99%) to ice-cooled aqueous solution of hydrazine hydrate (N2H4·2H2O, Qualizens Fine Chemicals,99%).
	With hydrazine monohydrate In ethanol at 0℃;
	With hydrazine hydrate monohydrate
	With hydrazine hydrate monohydrate In ethanol at 0℃;
	With hydrazine monohydrate
	With hydrazine monohydrate In water monomer	100.12 g of hydrazine hydrate was taken in a 1000 mL beaker. 146.14 g of diethyl oxalate was added to it and the mixture was dissolved in 225 mL of double distilled water. The entire addition was carried out in an ice bath with vigorous stirring. The resulting white precipitate was allowed to stand overnight. It was then washed with ethanol, filteredand dried.
	With hydrazine hydrate monohydrate for 0.5h;	1.12. Preparation of bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone Oxaloyldihydrazine was prepared by reacting diethyloxalate(20 mL) and hydrazine hydrate (13 mL) in 1:2M ratios under stirringfor 30 min. The product thus isolated was recrystallized fromH2O.Bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone(H4nph) was prepared by condensing oxaloyldihydrazine (3 g,25.42 mmol), in hot H2O (100 mL) with 2-hydroxy-1-naphthaladehyde (8.75 g, 50.84 mmol) in ethanol (20 mL) overhot plate at 70 C with constant stirring for 1 h. The yellow precipitatethus obtained was washed with hot H2O-ethanol and driedover anhydrous CaCl2.
	With hydrazine monohydrate for 0.5h;	5 1.5. Preparation of bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone (H₄nph) Oxaloyldihydrazine was prepared by reacting diethyloxalate(20 mL) and hydrazine hydrate (13 mL) in 1:2M ratios under stirringfor 30 min. The product thus isolated was recrystallized fromH2O.Bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone(H4nph) was prepared by condensing oxaloyldihydrazine (3 g,25.42 mmol), in hot H2O (100 mL) with 2-hydroxy-1-naphthaladehyde (8.75 g, 50.84 mmol) in ethanol (20 mL) overhot plate at 70 C with constant stirring for 1 h. The yellow precipitatethus obtained was washed with hot H2O-ethanol and driedover anhydrous CaCl2.
	With hydrazine monohydrate for 0.5h;
	With hydrazine hydrate monohydrate In ethanol for 0.333333h; Cooling with ice;
	With hydrazine monohydrate for 0.5h;	3 3 Preparation of bis(5-bromosalicylaldehyde)oxaloyldihydrazone (H₄sloxBr) Oxaloyldihydrazine was prepared by reacting 13 diethyl oxalate (10mL) and 14 hydrazine hydrate (7mL) in a 1:2M ratio under stirring for 30min. The product thus isolated was recrystallized from H2O.
0.34 g	With hydrazine In ethanol Reflux;	2.2 Synthesis of (N01E,N02E)-N01, N02-bis ((2-hydroxynaphthalen-1-yl) methylene)oxalohydrazide (1) General procedure: Compound 1 is prepared by three steps reaction procedure(Scheme 1).56-58 In the first step, oxalic acid (2 g, 22 mmol)is dissolved in ethanol (15 mL) and refluxed for 3-4 h inpresence of 4-5 drops of concentrated sulphuric acid.Ethanol is almost completely evaporated in vacuum and the remaining viscous liquid is extracted 3-4 times by CHCl3-H2O mixture. CHCl3 phase is collected and then dried byanhydrous Na2SO4 and evaporated by rotary evaporator togenerate diethyloxalate (2.57 g, 17.6 mmol). In the secondstep, diethyloxlate (0.5 g, 3.42 mmol) is reacted with excesshydrazine hydrate (0.256 mL, 8 mmol) in ethanol (20 mL)under reflux condition for 3-4 h and progress of the reactionis assessed by thin-layer chromatography (TLC). Thereaction mixture is cooled to room temperature and filtered.Oxalyldihydrazide (0.34 g, 2.87 mmol) is obtained aswhite solid. In the final step, oxalyldihydrazide (0.34 g,2.87 mmol) and 2-hydroxy-1-napthaldehyde (0.99 g,5.74 mmol) dissolved in EtOH (50 mL) and heated underreflux for 2 h. The reaction mixture is cooled and the yellowproduct is separated through filtration and washed withethanol to afford 1 in 81% yield (0.99 g, 2.32 mmol).
1.181 g	With hydrazine hydrate monohydrate for 0.333333h; Cooling with ice;
	With hydrazine monohydrate
	With hydrazine monohydrate at 24.84℃; for 16h; Reflux;

Reference： [1]Arunachalam, Rajendran; Aswathi, Chirayil S.; Das, Anjan; Kureshy, Rukhsana I.; Subramanian, Palani S. [ChemPlusChem, 2015, vol. 80, # 1, p. 209 - 216]
[2]Current Patent Assignee: CHINA NORTH INDUSTRIES GROUP CORPORATION - CN105272929, 2016, A Location in patent: Paragraph 0021-0022
[3]Syiemlieh, Ibanphylla; Kumar, Arvind; Kurbah, Sunshine D.; De, Arjune K.; Lal, Ram A. [Journal of Molecular Structure, 2018, vol. 1151, p. 343 - 352]
[4]Current Patent Assignee: HUNAN UNIVERSITY - CN110183349, 2019, A Location in patent: Paragraph 0027-0031
[5]Current Patent Assignee: KUMAMOTO HEALTH SCIENCE UNIVERSITY; GEN ASS PHARMA VALLEY PROJECT SUPPORTING ORGANIZAT - JP6120311, 2017, B2 Location in patent: Paragraph 0202-0203
[6]Szmuszkovicz,J.; Greig,M.E. [Journal of medicinal and pharmaceutical chemistry, 1961, vol. 4, p. 259 - 296]
[7]Cremlyn,R.J.W.; Turner,J.L. [Journal of the Chemical Society C: Organic, 1970, p. 2629 - 2631]
[8]Berdinskii, I. S.; Maslivets, A. N. [Journal of Organic Chemistry USSR (English Translation), 1982, vol. 18, p. 1609 - 1612][Zhurnal Organicheskoi Khimii, 1982, vol. 18, # 9, p. 1839 - 1843]
[9]Das, S.; Lal, R. A. [Indian Journal of Chemistry, Section A: Inorganic, Physical, Theoretical and Analytical, 1988, vol. 27, # 3, p. 225 - 230]
[10]Satpathy, K. C.; Panda, A. K.; Nayak, A.; Chinda, S. [Journal of the Indian Chemical Society, 1994, vol. 71, # 2, p. 89 - 92]
[11]Location in patent: experimental part Singh, Vinod P.; Singh, Shweta; Singh, Divya P. [Journal of Enzyme Inhibition and Medicinal Chemistry, 2012, vol. 27, # 3, p. 319 - 329]
[12]Chanu; Kumar; Lemtur; Lal [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012, vol. 96, p. 854 - 861]
[13]Singh; Kumar, Amit; Tiwari; Rawat, Poonam [Journal of Molecular Structure, 2013, vol. 1037, p. 420 - 430] Singh, Vinod P.; Singh, Shweta; Singh, Divya P.; Tiwari; Mishra, Monika [Journal of Molecular Structure, 2014, vol. 1058, # 1, p. 71 - 78]
[14]Islam, Rafiqul; Koizumi, Fumiaki; Kodera, Yasuo; Inoue, Kengo; Okawara, Tadashi; Masutani, Mitsuko [Bioorganic and Medicinal Chemistry Letters, 2014, vol. 24, # 16, p. 3802 - 3806]
[15]Mistri, Rajib; Maiti, Sayantani; Llorca, Jordi; Dominguez, Montserrat; Mandal, Tapas Kumar; Mohanty, Paritosh; Ray, Bidhan Chandra; Gayen, Arup [Applied Catalysis A: General, 2014, vol. 485, p. 40 - 50]
[16]Gupta, Samik; Kirillova, Marina V.; Guedes Da Silva, M. Fátima; Pombeiro, Armando J.L. [Applied Catalysis A: General, 2013, vol. 460-461, p. 82 - 89]
[17]Rawat, Poonam; Singh [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015, vol. 140, p. 344 - 355]
[18]Ibrahim, Hany S.; Abou-Seri, Sahar M.; Ismail, Nasser S.M.; Elaasser, Mahmoud M.; Aly, Mohamed H.; Abdel-Aziz, Hatem A. [European Journal of Medicinal Chemistry, 2016, vol. 108, p. 415 - 422]
[19]Ahmed, Ayman H.; Hassan; Mohamed, Bassem H.; Gumaa, Hosni A.; Eraky, Ahmed M. [Inorganic and Nano-Metal Chemistry, 2017, vol. 47, # 12, p. 1652 - 1663]
[20]Zulfiqar Ahmed; Chandrasekhar; Jahagirdar; Nagabhushana; Nagabhushana [Asian Journal of Chemistry, 2018, vol. 30, # 3, p. 607 - 612]
[21]Syiemlieh, Ibanphylla; Kumar, Arvind; Kurbah, Sunshine D.; Lal, Ram A. [Journal of Molecular Structure, 2018, vol. 1166, p. 102 - 109]
[22]Syiemlieh, Ibanphylla; Kumar, Arvind; Kurbah, Sunshine D.; Lal, Ram A. [Journal of Molecular Structure, 2018, vol. 1166, p. 252 - 261]
[23]Syiemlieh, Ibanphylla; Asthana, Mrityunjaya; Lal, Ram A. [Applied Organometallic Chemistry, 2019, vol. 33, # 8]
[24]Abu El-Reash; Zaky; El-Gamil, Mohammed M.; El-Emam [Journal of Molecular Liquids, 2019, vol. 288]
[25]Syiemlieh, Ibanphylla; Asthana, Mrityunjaya; Kurbah, Sunshine D.; Lal, Ram A. [Polyhedron, 2019, vol. 170, p. 202 - 216]
[26]Ghosh, Tamal; Raina, Ashish; Singh, Yadvendra; Yadav, Komal Kumar [Journal of Chemical Sciences, 2020, vol. 132, # 1]
[27]Abou-Melha, Khlood S. [Inorganic Chemistry Communications, 2021, vol. 133]
[28]Barshilia, Harish C.; Bera, Parthasarathi; Dubey, Varun; Hiremath, Maheshwarayya; Kundu, Asish K.; Lakshmi, R. V. [Physical Chemistry Chemical Physics, 2022, vol. 24, # 9, p. 5462 - 5478]
[29]Chen, Qiaojie; Gan, Kaifeng; Wang, Bin; Wei, Wei; Wu, Wei; Xu, Ke; Xu, Weiling [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2022, vol. 277]

6
[ 996-98-5 ]
[ 708-06-5 ]
(N'1E,N'2E)-N'1,N'2-bis((2-hydroxynaphthalen-1-yl)methylene)oxalohydrazide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
81%	In ethanol for 2h; Reflux;	2.2 Synthesis of (N01E,N02E)-N01, N02-bis ((2-hydroxynaphthalen-1-yl) methylene)oxalohydrazide (1) General procedure: Compound 1 is prepared by three steps reaction procedure(Scheme 1).56-58 In the first step, oxalic acid (2 g, 22 mmol)is dissolved in ethanol (15 mL) and refluxed for 3-4 h inpresence of 4-5 drops of concentrated sulphuric acid.Ethanol is almost completely evaporated in vacuum and the remaining viscous liquid is extracted 3-4 times by CHCl3-H2O mixture. CHCl3 phase is collected and then dried byanhydrous Na2SO4 and evaporated by rotary evaporator togenerate diethyloxalate (2.57 g, 17.6 mmol). In the secondstep, diethyloxlate (0.5 g, 3.42 mmol) is reacted with excesshydrazine hydrate (0.256 mL, 8 mmol) in ethanol (20 mL)under reflux condition for 3-4 h and progress of the reactionis assessed by thin-layer chromatography (TLC). Thereaction mixture is cooled to room temperature and filtered.Oxalyldihydrazide (0.34 g, 2.87 mmol) is obtained aswhite solid. In the final step, oxalyldihydrazide (0.34 g,2.87 mmol) and 2-hydroxy-1-napthaldehyde (0.99 g,5.74 mmol) dissolved in EtOH (50 mL) and heated underreflux for 2 h. The reaction mixture is cooled and the yellowproduct is separated through filtration and washed withethanol to afford 1 in 81% yield (0.99 g, 2.32 mmol). FTIR(KBr pellet, cm-1): OH (3624), NH (3250), CO (1630),C=N (1536), (Figure S1, Supplementary Information).1H NMR (DMSO-d6, 400 MHz, TMS) d/ppm: 7.24 (dd, 2H,J = 8.8 Hz), 7.4 (t, 2H, J = 7.4 Hz), 7.59-7.65 (m, 2H), 7.90(t, 2H, J = 9 Hz), 7.98 (d, 1H, J = 9.2 Hz), 8.13 (d, 1H,J = 9.2 Hz), 8.22 (d, 1H, J = 8.4 Hz), 8.93 (d, 1H, J = 8.4Hz), 9.73 (s, 2H), 10.81 (s, 2H), 12.59 (s, 2H) (Figure S2,Supplementary Information). ESI-Mass (m/z): 427.2769[M?H]? (Figure S3, Supplementary Information)
	In ethanol; water Heating;
	In ethanol Heating;

Reference： [1]Ghosh, Tamal; Raina, Ashish; Singh, Yadvendra; Yadav, Komal Kumar [Journal of Chemical Sciences, 2020, vol. 132, # 1]
[2]Lal, Ram A.; Adhikari, Syamal; Pal, Asim; Siva, Alaknanda N.; Kumar, Arvind [Journal of Chemical Research, Miniprint, 1997, # 4, p. 749 - 772]
[3]Lal, Ram A.; Basumatary, Debajani; Adhikari, Syamal; Kumar, Arvind [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008, vol. 69, # 3, p. 706 - 714]

7
oxalyl-bis-glycolic acid ester [ No CAS ]
[ 996-98-5 ]
[ 3530-14-1 ]

Reference： [1]Journal fur praktische Chemie (Leipzig 1954),1895,vol. <2> 51,p. 358

8
bis(2-ethoxy-2-oxoethyl) oxalate [ No CAS ]
[ 7803-57-8 ]
[ 996-98-5 ]
[ 3530-14-1 ]

Reference： [1]Journal fur praktische Chemie (Leipzig 1954),1895,vol. <2> 51,p. 358

9
[ 996-98-5 ]
[ 124-42-5 ]
[ 51824-96-5 ]

Yield	Reaction Conditions	Operation in experiment
95%	With sodium ethanolate In ethanol at 20℃; for 24h;

Reference： [1]Bahceci, Sule; Yueksek, Haydar; Serdar, Mevlut [Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2005, vol. 44, # 3, p. 568 - 572]

10
[ 996-98-5 ]
[ 1670-14-0 ]
[ 15921-10-5 ]

Yield	Reaction Conditions	Operation in experiment
84%	With sodium ethanolate In ethanol at 20℃; for 24h;

Reference： [1]Bahceci, Sule; Yueksek, Haydar; Serdar, Mevlut [Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 2005, vol. 44, # 3, p. 568 - 572]

11
[ 996-98-5 ]
[ 495-71-6 ]
[ 404866-72-4 ]

Yield	Reaction Conditions	Operation in experiment
	With 1-methyl-pyrrolidin-2-one In toluene at 170℃;	10 A suspension of dibenzoyl ethane (8.8 g, 37 mmol) in toluene (15 ml) and 1-methyl-2-pyrrolidinone (7.5 ml) was treated with oxalic dihydrazide (2 g, 17 mmol). The flask was fitted with a Dean Stark trap, and immersed in a 170° C. oil bath. The resulting suspension was stirred under Ar, with azeotropic removal of water until all of the starting diketone was consumed (determined by TLC), then cooled to rt. The solvent was removed in vacuo. The dark oily residue was washed with MeOH and filtered to afford a mixture (4.21 g) of N,N'-bis(2,5-diphenyl-1-pyrrolyl) oxamide contaminated with an unidentified impurity (on the order of 50-65% by weight), which was used without purification.

Reference： [1]Current Patent Assignee: DUPONT DE NEMOURS INC - US2003/228978, 2003, A1 Location in patent: Page/Page column 11

12
[ 471-46-5 ]
[ 996-98-5 ]

Yield	Reaction Conditions	Operation in experiment
97.8%	With hydrazine hydrate;	EXAMPLE 2 Preparation of oxalic acid dihydrazide 99% Hydrazine hydrate (61.8 g, 1.23 mol) is charged into a 100-ml, three-necked flask equipped with a thermometer, a reflux condenser, an inlet tube for nitrogen, and a magnetic stirrer. The temperature is brought to 30 C., and oxamide (10 g, 0.11 mol) is gradually stirred in. Ammonia which forms during the reaction, is removed as soon as it forms by a nitrogen stream. After two hours, the mixture is cooled to 20 C. and filtered under vacuum washing the precipitate on filter with methyl alcohol. The precipitate is then dried in the oven at 100 C., yielding the compound of the title (13.1 g, 97.8% yield) with m.p. 244-6 C. Elemental analysis: Calculated for C2 H6 N4 O2: C 20.34%; H 5.08%; N 47.46%. Found: C 20.28%; H 5.15%; N 47.01%.
97.8%	With hydrazine hydrate;	Example 2 Preparation of oxalic acid dihydrazide 99 % Hydrazine hydrate (61.8 g, 1.23 mol) is charged into a 100-ml, three-necked flask equipped with a thermometer, a reflux condenser, an inlet tube for nitrogen, and a magnetic stirrer. The temperature is brought to 30C, and oxamide (10 g, 0.11 mol) is gradually stirred in. Ammonia which forms during the reaction, is removed as soon as it forms by a nitrogen stream. After two hours, the mixture is cooled to 20C and filtered under vacuum washing the precipitate on filter with methyl alcohol. The precipitate is then dried in the oven at 100C, yielding the compound of the title (13.1 g, 97.8 % yield) with m.p. 244-6C.
93.2%	With hydrazine hydrate;	EXAMPLE 1 Preparation of oxalic acid dihydrazide 99% Hydrazine hydrate (50 ml, 51.5 g, 1.03 mol) is charged into a 100-ml, three-necked flask equipped with a thermometer, a reflux condenser, an inlet tube for nitrogen, and a magnetic stirrer. The temperature is brought to 50 C., and oxamide (10 g, 0.11 mol) is gradually stirred in. Ammonia which forms is removed as soon as it forms by a slow nitrogen stream. After two hours, the mixture is cooled to 25 C. and filtered under vacuum washing the precipitate on filter with methyl alcohol. The precipitate is then dried in the oven at 100 C., yielding the compound of the title (12.5 g, 0.11 mol, 93.2% yield) as a highly pure product. The FTIR spectrum of the thus obtained compound (absorption maxima at 3280, 3180, 1660, and 1620 cm-1) overlaps with that of an authentic sample.

93.2%

With hydrazine hydrate;

Example 1 Preparation of oxalic acid dihydrazide 99 % Hydrazine hydrate (50 ml, 51.5 g, 1.03 mol) is charged into a 100-ml, three-necked flask equipped with a thermometer, a reflux condenser, an inlet tube for nitrogen, and a magnetic stirrer. The temperature is brought to 50C, and oxamide (10 g, 0.11 mol) is gradually stirred in. Ammonia which forms is removed as soon as it forms by a slow nitrogen stream. After two hours, the mixture is cooled to 25C and filtered under vacuum washing the precipitate on filter with methyl alcohol. The precipitate is then dried in the oven at 100C, yielding the compound of the title (12.5 g, 0.11 mol, 93.2 % yield) as a highly pure product.

Reference： [1]Patent: US5017721,1991,A
[2]Patent: EP338387,1989,A1
[3]Patent: US5017721,1991,A
[4]Patent: EP338387,1989,A1

13
[ 40227-15-4 ]
[ 996-98-5 ]

Yield	Reaction Conditions	Operation in experiment
90.5%	With hydrazine hydrate	3 Preparation of oxalic acid dihydrazide EXAMPLE 3 Preparation of oxalic acid dihydrazide 98% Hydrazine hydrate (61.8g, 1.23 mol) is charged into a multi-necked flask equipped with a thermometer, a reflux condenser, an inlet tube for nitrogen, and a magnetic stirrer. Under stirring N,N'-diacetyloxamide (20 g, 0.116 mol) is added portionwise, while keeping the temperature of the reaction mixture at 25° C. The reaction mixture is then heated to 75° C. and allow to react for about 90 minutes. The mixture is then cooled to room temperature, filtered under vacuum and the precipitate on filter is washed with methyl alcohol. The compound of the title is thus obtained (12.4 g, 0.105 mol, 90.5% yield) with m.p. 245.7° C. Elemental analysis: Calculated for C2 H6 N4 O2: C 20.34%; H 5.08%; N 47.46% Found: C 20.30%; H 5.10%; N 47.40%

Reference： [1]Current Patent Assignee: ENI SPA - US5017721, 1991, A

14
diacetyloxamide [ No CAS ]
[ 996-98-5 ]

Yield	Reaction Conditions	Operation in experiment
90.5%	With hydrazine hydrate	3 Preparation of oxalic acid dihydrazide Example 3 Preparation of oxalic acid dihydrazide 98 % Hydrazine hydrate (61.8 g, 1.23 mol) is charged into a multi-necked flask equipped with a thermometer, a reflux condenser, an inlet tube for nitrogen, and a magnetic stirrer. Under stirring N,N--diacetyloxamide (20 g, 0.116 mol) is added portionwise, while keeping the temperature of the reaction mixture at 25°C. The reaction mixture is then heated to 75°C and allow to react for about 90 minutes. The mixture is then cooled to room temperature, filtered under vacuum and the precipitate on filter is washed with methyl alcohol. The compound of the title is thus obtained (12.4 g, 0.105 mol, 90.5% yield) with m.p. 245.7°C.

Reference： [1]Current Patent Assignee: ENI SPA - EP338387, 1989, A1

15
[ 996-98-5 ]
[ 764-05-6 ]
[ 1058256-02-2 ]

Yield	Reaction Conditions	Operation in experiment
56%	In water; acetone at 0 - 20℃; for 72h;

Reference： [1]Location in patent: scheme or table Joo, Young-Hyuk; Twamley, Brendan; Garg, Sonali; Shreeve, Jean'ne M. [Angewandte Chemie - International Edition, 2008, vol. 47, # 33, p. 6236 - 6239]

16
[ 996-98-5 ]
[ 764-05-6 ]
[ 1058256-06-6 ]

Yield	Reaction Conditions	Operation in experiment
64%	In water; acetone at 0 - 20℃; for 96h;

Reference： [1]Location in patent: scheme or table Joo, Young-Hyuk; Twamley, Brendan; Garg, Sonali; Shreeve, Jean'ne M. [Angewandte Chemie - International Edition, 2008, vol. 47, # 33, p. 6236 - 6239]

17
[ 996-98-5 ]
[ 14223-48-4 ]
[ 94650-34-7 ]

Yield	Reaction Conditions	Operation in experiment
92%	In N,N-dimethyl-formamide at 90℃; for 4h;	4.3. General procedure for the synthesis of bis(1,3,4-oxadiazoles) 6. (Take 6a, for example) General procedure: Oxalyl dihydrazide 5a (0.059 g, 0.5 mmol) and 1-chloro-4-isoselenocyanatobenzene 3B (0.217 g, 1.0 mmol) were added to DMF (10 mL) with magnetic stirring. The mixture was heated to 90 °C for 4 h. When the reaction was completed as monitored by TLC, the mixture was cooled to rt. The black selenium powder was filtered off and washed with ethanol (10 mL). The combined filtrate was concentrated in vacuo. The residue was crystallized, filtered and washed by ethanol (10 mL) to give N5,N5'-bis(4-chlorophenyl)-2,2'-bi(1,3,4-oxadiazole)-5,5'-diamine 6a (0.186 g, yield 96%) as a white solid.

Reference： [1]Location in patent: experimental part Xie, Yuanyuan; Liu, Junli; Yang, Ping; Shi, Xiangjun; Li, Jianjun [Tetrahedron, 2011, vol. 67, # 30, p. 5369 - 5374]

18
[ 996-98-5 ]
[ 1122-62-9 ]
[ 29816-35-1 ]

Yield	Reaction Conditions	Operation in experiment
78%	In ethanol for 3h; Reflux;	2.2. Synthesis of 2,2-N^1',N^2'-bis(1-(pyridin-2-yl)ethylidene)oxalohydrazide (H2L) It was prepared by heating 1:2 M ratio of oxalohydrazide (1.18 g, 0.01 mol) and 2-acetylpyridine (2.24 ml, 0.02 mol) in30 ml hot ethanol. The reaction mixture was boiled under reflux for 3 h, evaporated and after cooling, white crystals of H2L (Structure 1) were formed. The precipitate was filtered off, recrystallized from ethanol and finally dried in a vacuum desiccator over anhydrous CaCl2. The purity was checked by TLC. The melting point is 261 °C (yield is 78%).

Reference： [1]Location in patent: experimental part El-Gammal; El-Shazly; El-Morsy; El-Asmy [Journal of Molecular Structure, 2011, vol. 998, # 1-3, p. 20 - 29]

19
[ 996-98-5 ]
[ 708-06-5 ]
[ 63968-59-2 ]

Yield	Reaction Conditions	Operation in experiment
98%	In ethanol; water for 3h; Reflux;
84.3%	In methanol for 6h; Reflux;	2.2. Preparation of Probe 1 Probe 1 was prepared from the condensation of oxaloyldihydrazinewith 2-hydroxy-1-naphthaldehyde as shown in Scheme 1, and furthercharacterized by MS and 1H NMR (Fig. S1). Oxaloyldihydrazine(0.6000 g, 5 mmol) was suspended first in methanol (50 mL) followedby adding 2.02 g (11.7 mmol) of 2-hydroxy-1-naphthaldehyde, then the mixture was refluxed for 6 h under stirring. After the reaction, alarge amount of yellow precipitate was produced in the system, andthen the precipitate was filtered after cooling, and washed with asmall amount of cold methanol to give a yellow powdery product.(1.7981 g, 84.3%). The resulting yellow power was crystallized fromDMSO to give yellow crystals of compound 1. 1H NMR (400 MHz,DMSO d6): 7.26 (d, J = 8.0 Hz, 2H), 7.44 (t, J = 6.0 Hz, 2H), 7.65(t, J= 6.0 Hz, 2H), 7.93 (d, J = 8.0 Hz, 2H), 7.99 (d, J = 8.0 Hz, 2H), 8.24(d, J = 8.0 Hz, 2H), 9.75 (s, 2H), 12.59 (s, 2H), 12.79 (s, 2H). MS: m/z=427.13 [1+H+].
48%	In ethanol for 2h; Reflux;	N'¹,N'²-bis(2-hydroxy-1-naphthylmethylene)oxalohydrazide (H4L1) A mixture of oxalyl dihydrazide(1.50 g, 12.7 mmol) and 2-hydroxy-1-naphthaldehyde (4.80 g,25.4 mmol) in anhydrous ethanol solution (600 mL) was refluxedfor 2 h under constant stirring using magnetic stirrer. The productwas filtered and washed with ethanol, then dried in vacuo. The yellowpowder product was obtained. Yield: 48%. Anal. Calc. (%) forC24H18N4O4 (M = 426.13 gmol1): C, 67.60; H, 4.25; N, 13.14.Found: C, 68.10; H, 4.15; N, 13.04. EIS-MS (m/z): [H3L1], 425.12.FT-IR (KBr phase, cm1): 3454(s, OAH), 3293(s, NAH), 1660(s,CO), 1622(s, CN), 1283(m, CAO), 1041(w, NAN). 1H NMR(300 MHz, DMSO-d6): d = 7.23-8.21(m, 12H, naphthyl), 9.72(s,2H, CHN), 12.58(s, 2H, OH), 12.79(s, 2H, NH).

	In methanol; water for 1.5h; Heating; Reflux;	Preparation of bis(2-hydroxy-1-naphthaldehyde) oxaloyldihydrazone Aqueous solution of oxaloyldihydrazine (3.00 g, 25.42 mmol) was mixed with methanolic solution of bis(2-hydroxy-1-naphthaldehyde) (10.93 g, 63.55 mmol) in hot condition. The reaction mixture was heated for about half an hour accompanied by stirring. This was then transferred to a round bottom flask and refluxed for 1 h. This precipitated a yellow compound which was cooled to room temperature and suction filtered. The precipitate was washed thoroughly with hot methanol and dried over anhydrous CaCl2. m.p. > 300 °C(dec). Found: C, 68.00; H, 4.25; N, 13.32; Calcd. For C24H18N4O4; C, 67.61; H, 4.25; N, 13.15.
	In methanol; water for 3h; Reflux;	Preparation of oxaloyldihydrazone ligands General procedure: In view of the importance of oxaloyldihydrazones and their chelates, we have undertaken the synthesis of four ligand structures including bis(salicylaldehyde)oxaloyldihydrazone (L1), bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone (L2), bis(2-hydroxyacetophenone)oxaloyldihydrazone (L3), bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L4). Oxalicdihydrazide(0.01 mol) dissolved first in hot water (20 cm3) followed by adding methanol (40 cm3) was mixed with the appropriate aldehydes [salicylaldehyde, 2-hydroxy-1-naphthaldehyde,2-hydroxyacetophenone and 2-methoxybenzaldehyde](0.02 mol) in absolute methanol. The resulting mixture went onr efluxing for 3 hrs under constant stirring. The product was separated out on concentrating the solution to half of its volume and cooling. The crystals of the desired ligand was collected by filtration through a Buchner funnel and dried in an electricoven at 50° C for 2 h. Afterwards the ligand was recrystallizedfrom DMF-MeOHaq mixed solvent, collected, washed thoroughly on filter paper by acetone to remove any excess of DMF and then dried in an electric oven at 50 °C for 2 h. The molecular structure of the resulting hydrazones was elucidated by elemental analyses and spectral (IR, mass and 1H NMR)measurements (Table 2, 3).
	In ethanol; water at 70℃; for 1h; Heating;	1.12. Preparation of bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone Oxaloyldihydrazine was prepared by reacting diethyloxalate(20 mL) and hydrazine hydrate (13 mL) in 1:2M ratios under stirringfor 30 min. The product thus isolated was recrystallized fromH2O.Bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone(H4nph) was prepared by condensing oxaloyldihydrazine (3 g,25.42 mmol), in hot H2O (100 mL) with 2-hydroxy-1-naphthaladehyde (8.75 g, 50.84 mmol) in ethanol (20 mL) overhot plate at 70 C with constant stirring for 1 h. The yellow precipitatethus obtained was washed with hot H2O-ethanol and driedover anhydrous CaCl2.
	In ethanol at 70℃; for 1h;	1.5. Preparation of bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone (H4nph) Oxaloyldihydrazine was prepared by reacting diethyloxalate(20 mL) and hydrazine hydrate (13 mL) in 1:2M ratios under stirringfor 30 min. The product thus isolated was recrystallized fromH2O.Bis(2-hydroxy-1-napthhaladehyde)oxaloyldihydrazone(H4nph) was prepared by condensing oxaloyldihydrazine (3 g,25.42 mmol), in hot H2O (100 mL) with 2-hydroxy-1-naphthaladehyde (8.75 g, 50.84 mmol) in ethanol (20 mL) overhot plate at 70 °C with constant stirring for 1 h. The yellow precipitatethus obtained was washed with hot H2O-ethanol and driedover anhydrous CaCl2.
	In methanol; water for 3h; Heating;	Synthesis of oxaloyldihydrazone ligands General procedure: The dihydrazone ligands; bis(2-hydroxynaphthaldehyde)oxaloyldihydrazone (L1) and bis(2-methoxybenzaldehyde)oxaloyldihydrazone(L2) were prepared using the same procedure described in Ref. 10 as follows.Aqueous methanolic solution of oxaloyldihydrazine was mixed with absolutemethanolic solution of the selected aldehydes (maintaining the molar ratioat 1:2) in hot condition. The reaction mixture was heated for about 3 hoursaccompanied by stirring. The precipitate was separated out on concentratingthe solution to half of its volume and cooling. Afterwards, the isolatedcompound was filtered, recrystallized from DMF-MeOHaq mixed solvent,washed thoroughly by acetone and then dried in an electric oven at 80 °C for2 h. The molecular structure of the resulting hydrazones was confirmed byelemental analyses, (IR, mass and 1H/13C NMR) spectroscopy (Table 1, 2).The mass spectral data of the ligands (L1, L2) are displayed in Fig. 1 and theobtained M+ values are set out in Table 1. Mass spectrum of the bis(2-hydroxy-1-naphthaldhyde)oxaloyldihydrazone (L1) revealed ion peaks at m/e = 427(20%, molecular peak, (C16H14N4O4)), 410 (25%, M+(C24H18N4O3)), 270 (21%,M+(C13H10N4O3)), 157 (21.2%, M+(C11H9O)), 257 (50%, M+(C13H10N3O3)), 242(40%, M+(C13H9N2O3)), 175 (71%, M+(C11H9NO)), 141 (4%, M+(C11H9)), 128 (37%, M+(C10H8)), 79 (40%, M+(C6H8)), 64.95 (71%, M+(C5H5)) and 50 (100%,base peak, M+(C4H4). Mass spectrum of the bis(2-methoxybenzaldehyde)oxaloyldihydrazone (L2) exhibited ion peaks at m/e = 356.45 (33%,molecular peak, (C18H18N4O4)), 247.35 (26%, M+(C11H11N4O3)), 217.2 (62%,M+(C10H9N4O2)), m/e = 50 (100%, base peak, M+(C4H4)), 234.2 (42%,M+(C10H10N4O3)), 202 (25%, M+(C10H9N2O3)), 176.5 (60%, M+(C9H9N2O2)),149 (92%, M+(C8H9N2O)), 190.6 (46%, M+(C9H8N3O2)), 175.55 (78%,M+(C9H7N2O2)), 119.4 (53%, M+(C7H7N2)), 104.2 (51%, M+(C7H6N)), 134.6(82%, M+(C8H8NO)), 107.15 (52%, M+(C7H8O)), m/e = 90.6 (75%, M+(C7H6)),77.05 (86%, M+(C6H6)) as well as 66.65 (38%) corresponds to M+(C5H6).

Reference： [1]Ahmed, Ayman H. [Open Chemistry, 2020, vol. 18, # 1, p. 426 - 437]
[2]Xing, Chunbo; Hao, Libo; Zang, Libin; Tang, Xiaodan; Zhao, Yuyan; Lu, Jilong [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2020, vol. 224]
[3]Shi, Jingnan; Wei, Yi; Zhang, Yuzhen; Tang, Jie; Bian, Hedong; Yu, Qing; Huang, Fuping [Polyhedron, 2019, vol. 162, p. 81 - 90]
[4]Chanu; Kumar; Lemtur; Lal [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2012, vol. 96, p. 854 - 861]
[5]Ahmed, Ayman H.; Hassan; Mohamed, Bassem H.; Gumaa, Hosni A.; Eraky, Ahmed M. [Inorganic and Nano-Metal Chemistry, 2017, vol. 47, # 12, p. 1652 - 1663]
[6]Syiemlieh, Ibanphylla; Kumar, Arvind; Kurbah, Sunshine D.; Lal, Ram A. [Journal of Molecular Structure, 2018, vol. 1166, p. 102 - 109]
[7]Syiemlieh, Ibanphylla; Kumar, Arvind; Kurbah, Sunshine D.; Lal, Ram A. [Journal of Molecular Structure, 2018, vol. 1166, p. 252 - 261]
[8]Ahmed, Ayman H.; Hassan; Gumaa, Hosni A.; Mohamed, Bassem H.; Eraky, Ahmed M. [Journal of the Chilean Chemical Society, 2018, vol. 63, # 4, p. 4180 - 4189]

20
[ 996-98-5 ]
[ 70582-64-8 ]
[ 1426954-91-7 ]

Yield	Reaction Conditions	Operation in experiment
41.13%	With hydrogenchloride In methanol; water for 8h; Reflux;	1 2.1 Synthesis of ethyl 2-cyano-3-[5-(hydrazinooxalyl-hydrazonomethyl)-1H-pyrrol-2-yl]-acrylate (3) Ethyl 2-cyano-3-(5-formyl-1H-pyrrol-2-yl)-acrylate (1) (0.250 g, 1.1464 mmol) was dissolved in methanol and oxalyl dihydrazide (2) (0.1354 g, 1.1464 mmol) in hot water. The solution of (2) and 0.01 ml of conc. HCl as catalyst were added drop-wise in solution of (1) and the reaction mixture was refluxed while stirring for 8 h. The formed yellow color precipitate was filtered off using vacuum filtration, washed with methanol and dried in air, afforded (0.150 g, 41.13%) of (3), as yellow color solid. Anal. calcd. for C13H14N6O4: C 49.04%, H 4.43%, N 26.41%, obs.: C 49.18%, H 4.48%, N 26.52%. MS (m/z): obs. 319.24 [M++1], calcd. 318.10765.

Reference： [1]Singh; Kumar, Amit; Tiwari; Rawat, Poonam [Journal of Molecular Structure, 2013, vol. 1037, p. 420 - 430]

21
[ 996-98-5 ]
trifluoroacetamidine [ No CAS ]
C₆H₂F₆N₆ [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
42%	In ethanol for 24h; Reflux; Inert atmosphere;	1 Synthesis Example 1 Synthesis Example 1 [0054] Oxalyl dihydrazide (1.00 g, 8.5 mmol) and trifluoroacetamidine (2.37 g, 21.2 mmol) were placed in a 150 ml reaction flask, followed by adding 100 ml ethanol to obtain a mixture. The mixture was heated under reflux under a nitrogen gas atmosphere for 24 hours. After the reaction was finished, the mixture was cooled to room temperature. A filtration process was conducted and a white filter cake was collected, followed by washing the white filter cake using deionized water. Next, the filter cake was placed in a 50 ml reaction flask, followed by heating for 2 hours at 280° C. A reduced pressure sublimation process was conducted to obtain a colorless solid (0.968 g, 3.56 mmol, 42% yield). [0055] The spectrum analysis for the colorless solid is: 19F-{1H} NMR (470 MHz, d6-dimethyl sulfoxide, 294K), δ (ppm): -65.80 (s, CF3); MS (EI): m/z 272 [M]+.
42%	In ethanol for 24h; Reflux; Inert atmosphere;	2 Synthesis Example 1 (0077) Oxalyl dihydrazide (1.00 g, 85 mmol) and trifluoroacetamidine (2.37 g, 21.2 mmol) were placed in a 150 ml reaction flask, followed by addition of 100 ml ethanol to obtain a mixture. The mixture was heated under reflux and under a nitrogen atmosphere for a period of 24 hours. After the reaction was completed and the temperature was cooled down to room temperature, the mixture was subjected to a filtration process to collect a white filter cake, which was then washed using deionized water. Next, the filter cake was placed in a 50 ml reaction flask, was heated to and maintained at 280° C. for 2 hours, and then was subjected to a reduced pressure sublimation process to obtain a white solid product (0.968 g, 3.56 mmol, 42% yield).

Reference： [1]Current Patent Assignee: TSINGHUA UNIVERSITY (TAIWAN) - US2013/296567, 2013, A1 Location in patent: Paragraph 0054; 0055
[2]Current Patent Assignee: TSINGHUA UNIVERSITY (TAIWAN) - US8957208, 2015, B1 Location in patent: Page/Page column 9; 10

22
[ 996-98-5 ]
[ 93-91-4 ]
N,N-bis(4-oxo-4-phenylbutan-2-ylidene)oxalohydrazide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
79.7%	In methanol for 5h; Reflux;	2.3.1. Synthesis of the Schiff base The ligand, N,N-bis(4-oxo-4-phenylbutan-2-ylidene)oxalohydrazide (I) has been prepared by refluxing a mixture of 1-benzoylacetone (0.922 g, 5.68 mmol) and oxalyldihydrazide (0.335 g, 2.84 mmol) in dry methanol (25 ml) for 5 h. A light-yellow crystalline solid was separated out on cooling the reaction mixture to room temperature. This was filtered, washed with methanol and dried. Yield: 0.92 g (79.7%), Anal. data (%): Found: C, 64.92; H, 5.53;N,13.66; Calc. for C22H22N4O4 (formula weight: 406.43), C, 65.01; H,5.46; N, 13.78. 1H NMR (400.15 MHz, DMSO-d6): 7.56 (s, 1H), 7.37 (t,2H), 7.28 (t, 1H), 7.15 (s, 1H), 3.07 (dd, 2H), 2.036 (s, 3H); 13C NMR (100.61 MHz, DMSO-d6): 160.22, 155.70, 142.90, 127.85, 127.29,126.87, 125.03, 92.34, 15.78. Probable molecular structure of the ligand is given in Fig. 2.

Reference： [1]Dey, Dilip Kumar; Dey, Sankar Prasad; Karan, Nirmal Kumar; Lyčka, Antonin; Rosair, Georgina M. [Journal of Organometallic Chemistry, 2014, vol. 749, p. 320 - 326]

23
[ 996-98-5 ]
[ 1122-62-9 ]
N',N'²-bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
72%	With triethylamine In methanol for 24h; Reflux;	Synthesis of Sm(III)-polytonic ligand- N',N'²-bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide -{Sm2-L₂-(CH₃COO)₂} The ligand was prepared by mixing 2.70 g of 2-acetyl pyridine (1 mmol) with 1.18 g of oxalic dihydrazide (1 mmol) in a 100.0 mL round bottom flask containing 50.0 mL methanol followed by drop wise addition of 2.0 g triethyl amine as a catalyst. The mixture was refluxed for 24 h, a white solid formed which was filtered off, washed with methanol and vacuum dried (Yield:72%), melting point = 269 °C (Fig. S2).

Reference： [1]Zaitoun; Momani; Jaradat; Qurashi [Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2013, vol. 115, p. 810 - 814]

24
[ 996-98-5 ]
[ 131543-46-9 ]
[ 90-02-8 ]
[ 7646-79-9 ]
[Co(glyoxal salicylaldehyde oxalic acid dihydrazone(-H))]Cl [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	Stage #1: Glyoxal; salicylaldehyde; cobalt(II) chloride In ethanol at 20℃; for 0.5h; Stage #2: oxalic acid hydrazide In ethanol; water at 20℃; for 2h;	Synthesis of the metal complexes General procedure: A mixture of 25 ml ethanolic solution of glyoxal (10 mmol,0.58 ml) and salicylaldehyde (10 mmol, 1.22 ml) was added into 50 ml ethanolic solutions of each metal(II) chloride (10 mmol) in a round bottom flask, separately. The above solution was stirred on a magnetic stirrer for 30 minutes at room temperature. To this reaction solution, 50 ml aqueous solution of oxalic acid dihydrazide(10 mmol, 1.18 g) and malonic acid dihydrazide (10 mmol,1.32 g) was added, separately, drop wise with stirring. The metal complexes were obtained as insoluble precipitates on stirring the reaction solutions continuously for 2 hours at room temperature. The complexes were filtered in a glass crucible by suction and washed several times with ethanol and finally with diethyl ether.

Reference： [1]Singh, Vinod P.; Singh, Shweta; Singh, Divya P.; Tiwari; Mishra, Monika [Journal of Molecular Structure, 2014, vol. 1058, # 1, p. 71 - 78]

25
[ 996-98-5 ]
[ 131543-46-9 ]
[ 90-02-8 ]
nickel dichloride [ No CAS ]
[Ni(glyoxal salicylaldehyde oxalic acid dihydrazone(-H))]Cl [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	Stage #1: Glyoxal; salicylaldehyde; nickel dichloride In ethanol at 20℃; for 0.5h; Stage #2: oxalic acid hydrazide In ethanol; water at 20℃; for 2h;	Synthesis of the metal complexes General procedure: A mixture of 25 ml ethanolic solution of glyoxal (10 mmol,0.58 ml) and salicylaldehyde (10 mmol, 1.22 ml) was added into 50 ml ethanolic solutions of each metal(II) chloride (10 mmol) in a round bottom flask, separately. The above solution was stirred on a magnetic stirrer for 30 minutes at room temperature. To this reaction solution, 50 ml aqueous solution of oxalic acid dihydrazide(10 mmol, 1.18 g) and malonic acid dihydrazide (10 mmol,1.32 g) was added, separately, drop wise with stirring. The metal complexes were obtained as insoluble precipitates on stirring the reaction solutions continuously for 2 hours at room temperature. The complexes were filtered in a glass crucible by suction and washed several times with ethanol and finally with diethyl ether.

Reference： [1]Singh, Vinod P.; Singh, Shweta; Singh, Divya P.; Tiwari; Mishra, Monika [Journal of Molecular Structure, 2014, vol. 1058, # 1, p. 71 - 78]

26
[ 996-98-5 ]
[ 131543-46-9 ]
[ 90-02-8 ]
copper dichloride [ No CAS ]
[Cu(glyoxal salicylaldehyde oxalic acid dihydrazone(-H))]Cl [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	Stage #1: Glyoxal; salicylaldehyde; copper dichloride In ethanol at 20℃; for 0.5h; Stage #2: oxalic acid hydrazide In ethanol; water at 20℃; for 2h;	Synthesis of the metal complexes General procedure: A mixture of 25 ml ethanolic solution of glyoxal (10 mmol,0.58 ml) and salicylaldehyde (10 mmol, 1.22 ml) was added into 50 ml ethanolic solutions of each metal(II) chloride (10 mmol) in a round bottom flask, separately. The above solution was stirred on a magnetic stirrer for 30 minutes at room temperature. To this reaction solution, 50 ml aqueous solution of oxalic acid dihydrazide(10 mmol, 1.18 g) and malonic acid dihydrazide (10 mmol,1.32 g) was added, separately, drop wise with stirring. The metal complexes were obtained as insoluble precipitates on stirring the reaction solutions continuously for 2 hours at room temperature. The complexes were filtered in a glass crucible by suction and washed several times with ethanol and finally with diethyl ether.

Reference： [1]Singh, Vinod P.; Singh, Shweta; Singh, Divya P.; Tiwari; Mishra, Monika [Journal of Molecular Structure, 2014, vol. 1058, # 1, p. 71 - 78]

27
[ 996-98-5 ]
[ 131543-46-9 ]
[ 90-02-8 ]
[ 7646-85-7 ]
[Zn(glyoxal salicylaldehyde oxalic acid dihydrazone(-H))]Cl [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	Stage #1: Glyoxal; salicylaldehyde; zinc(II) chloride In ethanol at 20℃; for 0.5h; Stage #2: oxalic acid hydrazide In ethanol; water at 20℃; for 2h;	Synthesis of the metal complexes General procedure: A mixture of 25 ml ethanolic solution of glyoxal (10 mmol,0.58 ml) and salicylaldehyde (10 mmol, 1.22 ml) was added into 50 ml ethanolic solutions of each metal(II) chloride (10 mmol) in a round bottom flask, separately. The above solution was stirred on a magnetic stirrer for 30 minutes at room temperature. To this reaction solution, 50 ml aqueous solution of oxalic acid dihydrazide(10 mmol, 1.18 g) and malonic acid dihydrazide (10 mmol,1.32 g) was added, separately, drop wise with stirring. The metal complexes were obtained as insoluble precipitates on stirring the reaction solutions continuously for 2 hours at room temperature. The complexes were filtered in a glass crucible by suction and washed several times with ethanol and finally with diethyl ether.

Reference： [1]Singh, Vinod P.; Singh, Shweta; Singh, Divya P.; Tiwari; Mishra, Monika [Journal of Molecular Structure, 2014, vol. 1058, # 1, p. 71 - 78]

28
[ 996-98-5 ]
[ 131543-46-9 ]
[ 90-02-8 ]
C₁₁H₁₀N₄O₄ [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
78%	In ethanol; water at 60℃; for 2h;	Synthesis of glyoxal salicylaldehyde oxalic acid dihydrazone The ligand glyoxal salicylaldehyde oxalic acid dihydrazone (gsodh) was synthesized by reacting 100 ml hot aqueous solution of oxalic acid dihydrazide (10 mmol, 1.18 g) with 50 ml aqueous ethanolic solution of a mixture containing glyoxal (10 mmol,0.58 ml) and salicylaldehyde (10 mmol, 1.22 ml) in a round bottomflask. A light yellow coloured precipitate of the product was obtained on stirring the above solution on a magnetic stirrer continuously for 2 hours at 60 °C. The precipitate was filtered on a Büchner funnel and washed several times with hot water followed by ethanol to remove any un-reacted reactants. The pure product was dried in a desiccator over anhydrous calcium chloride. Light yellow, yield (78%). M.p. >300 °C. Anal. Calc. for C11H10N4O4 (262): C, 50.38; H, 3.82; N, 21.37. Found: C, 50.55; H, 3.86; N,21.48%. IR (ν cm-1, KBr): ν(OH) 3449b; ν(NH) 3207b; ν(C=O)1665b; ν(C=N) 1628s; ν(N-N) 970w.

Reference： [1]Singh, Vinod P.; Singh, Shweta; Singh, Divya P.; Tiwari; Mishra, Monika [Journal of Molecular Structure, 2014, vol. 1058, # 1, p. 71 - 78]

29
[ 996-98-5 ]
aluminum(III) nitrate nonahydrate [ No CAS ]
calcium nitrate hexahydrate [ No CAS ]
None [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	at 500℃;	For the synthesis of Eu:CaAl2O4, Eu2O3 is first converted to Eu(NO3)3. Calculatedamounts of Eu2O3 are dissolved in 1:1 HNO3 and excess nitric acid is evaporated onsand bath at 80 C to obtain transparent europium nitrate solution. Requiredamount of ODH and aqueous mixture of calcium nitrate and aluminium nitrateare subsequently added to the europium nitrate solution while continuously stirringthe mixture, to ensure homogeneous mixing. The petri dish containing the heterogeneousredox mixture is introduced into a muffle furnace maintained at500 ± 10 C. Initially the solution boils and undergoes dehydration. Eventually the mixture undergoes decomposition, which results in the liberation of large amountsof gases (usually CO2, H2O and N2). This is followed by a spontaneous ignition whichresults in flame type combustion [30]. The swelling of the reactant mixture is verytypical of the flame type combustion. The whole process is over in less than 5 minand a highly porous white Eu:CaAl2O4 nanopowder is obtained.

Reference： [1]Hari Krishna; Nagabhushana; Nagabhushana; Chakradhar; Suriya Murthy; Sivaramakrishna; Shivakumara; Rao; Thomas, Tiju [Journal of Alloys and Compounds, 2014, vol. 589, p. 596 - 603]

30
[ 996-98-5 ]
[ 66-72-8 ]
[ 901361-93-1 ]

Yield	Reaction Conditions	Operation in experiment
0.167 g	In water at 40℃; for 0.166667h; Inert atmosphere;	2.2.1. Bis((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)oxalohydrazide (H6Pyr2oxdihyd) Pyridoxine hydrochloride (0.191 g, 1 mmol) was dissolved in 100 mL of water. In this solution 0.88 g of 85% MnO2 was suspended and 1 mL of concentrated sulfuric acid was added very slowly. Thereafter the mixture was heated in an oil-bath at 60-70 °C for ca. 4 h until whole dissolution of the manganese dioxide. The solution becomes brown however translucent due to the whole oxidation of pyridoxine to pyridoxal. The ligand H6pyr2dihyd precipitated after the addition of 0.118 g of oxalic acid hydrazide. The mixture was heated in an oil-bath at 40 °C for about 10 min and the ligand was collected on a filter, washed with distilled water and dried. Yield: 0.167 g (86%).

Reference： [1]Back, Davi Fernando; Manzoni De Oliveira, Gelson; Roman, Daiane; Ballin, Marco Aurélio; Kober, Roger; Piquini, Paulo Cesar [Inorganica Chimica Acta, 2014, vol. 412, p. 6 - 14]

31
[ 996-98-5 ]
[ 2144-08-3 ]
[ 386257-59-6 ]

Yield	Reaction Conditions	Operation in experiment
88%	With acetic acid In methanol Reflux;	General procedure for the synthesis of compounds 3a-f, 5a-f and 8a-h: General procedure: A mixture of an appropriate dihydrazide (1 mmol), an appropriate hydroxybenzaldehyde (2 mmol) and acetic acid (2/3 drops) in methanol (25 ml) was heated under reflux with stirring for 6-8 h. Then the reaction mixture was cooled with stirring. Precipitated solid was collected by filtration, and washed with little ethanol and hexane to give the target products 3a-f, 5a-f and 8a-h.

Reference： [1]Islam, Rafiqul; Koizumi, Fumiaki; Kodera, Yasuo; Inoue, Kengo; Okawara, Tadashi; Masutani, Mitsuko [Bioorganic and Medicinal Chemistry Letters, 2014, vol. 24, # 16, p. 3802 - 3806]

32
[ 996-98-5 ]
[ 13677-79-7 ]
[ 1622386-14-4 ]

Yield	Reaction Conditions	Operation in experiment
86%	With acetic acid In methanol Reflux;	General procedure for the synthesis of compounds 3a-f, 5a-f and 8a-h: General procedure: A mixture of an appropriate dihydrazide (1 mmol), an appropriate hydroxybenzaldehyde (2 mmol) and acetic acid (2/3 drops) in methanol (25 ml) was heated under reflux with stirring for 6-8 h. Then the reaction mixture was cooled with stirring. Precipitated solid was collected by filtration, and washed with little ethanol and hexane to give the target products 3a-f, 5a-f and 8a-h.

Reference： [1]Islam, Rafiqul; Koizumi, Fumiaki; Kodera, Yasuo; Inoue, Kengo; Okawara, Tadashi; Masutani, Mitsuko [Bioorganic and Medicinal Chemistry Letters, 2014, vol. 24, # 16, p. 3802 - 3806]

33
[ 996-98-5 ]
cobalt(II) nitrate hexahydrate [ No CAS ]
[ 120-46-7 ]
[ 1621608-61-4 ]