Name: 86-77-1|Dibenzo[b,d]furan-2-ol|95%
Brand: Ambeed
SKU: A703749
Price: 8.0 USD
Availability: InStock
Rating: 97 (40 reviews)

1
[ 86-77-1 ]
[ 91267-95-7 ]

Yield	Reaction Conditions	Operation in experiment
63%	With N-Bromosuccinimide In ethanol
34%	With N-Bromosuccinimide In ethanol at 20℃; for 4h;	3 Synthesis Example 3: Synthesis of Intermediate Int-03 The intermediate (Int-02) (29 g, 157.45 mmol) and N-bromosuccinimide (25.22 g, 147.70 mmol) were placed in a round bottom flask and dissolved in 150 ml of EtOH. It was then stirred at room temperature for 4 hours. When the reaction was completed, the resultant was poured into an excess of water. After the resulting mixture was stirred for 1 hour, remove the water layer from it, and obtained by column chromatography, 14.08 g (34%) intermediate (Int-03).
	With bromine; acetic acid

Reference： [1]Prado, Soizic; Janin, Yves L.; Saint-Joanis, Brigitte; Brodin, Priscille; Michel, Sylvie; Koch, Michel; Cole, Stewart T.; Tillequin, Francois; Bost, Pierre-Etienne [Bioorganic and Medicinal Chemistry, 2007, vol. 15, # 5, p. 2177 - 2186]
[2]Current Patent Assignee: SAMSUNG SDI CO.,LTD.; SAMSUNG ELECTRONICS CO.,LTD. - CN110294703, 2019, A Location in patent: Paragraph 0201; 0210-0213
[3]Gilman; Van Ess [Journal of the American Chemical Society, 1939, vol. 61, p. 1365,1369]

2
[ 3693-22-9 ]
[ 86-77-1 ]

Reference： [1]Journal of the American Chemical Society,1935,vol. 57,p. 885
[2]Patent: DE591213,1932,
Fortschr. Teerfarbenfabr. Verw. Industriezweige,vol. 20,p. 436

3
[ 5397-82-0 ]
[ 86-77-1 ]
[ 22439-48-1 ]

Yield	Reaction Conditions	Operation in experiment
1: 2% 2: 85%	With 3-chloro-benzenecarboperoxoic acid In dichloromethane for 10h; Ambient temperature;
1: 81% 2: 1%	With dihydrogen peroxide In formic acid at 20℃; for 20h; various mol ratios of H₂O₂, in various solvents;

Reference： [1]Fujishiro, Koichi; Mitamura, Shuichi [Bulletin of the Chemical Society of Japan, 1988, vol. 61, # 12, p. 4464 - 4466]
[2]Fujishiro, Koichi; Mitamura, Shuichi [Bulletin of the Chemical Society of Japan, 1988, vol. 61, # 12, p. 4464 - 4466]

4
[ 20357-70-4 ]
[ 86-77-1 ]

Yield	Reaction Conditions	Operation in experiment
98%	With L-Selectride In tetrahydrofuran at 67℃; for 48h;
95%	With 1-n-butyl-3-methylimidazolim bromide; toluene-4-sulfonic acid; 1-butyl-3-methylimidazolium Tetrafluoroborate at 115℃; for 10h;

Reference： [1]Majetich, George; Zhang, Yong; Wheless, Karen [Tetrahedron Letters, 1994, vol. 35, # 47, p. 8727 - 8730]
[2]Boovanahalli, Shanthaveerappa K.; Kim, Dong Wook; Chi, Dae Yoon [Journal of Organic Chemistry, 2004, vol. 69, # 10, p. 3340 - 3344]

5
[ 86-77-1 ]
[ 7462-74-0 ]
N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide [ No CAS ]

Reference： [1]Tetrahedron,1997,vol. 53,p. 6303 - 6312

6
[ 108-95-2 ]
[ 86-77-1 ]
[ 19261-06-4 ]
[ 2417-10-9 ]
[ 1806-29-7 ]

Reference： [1]European Journal of Organic Chemistry,2000,p. 921 - 928

7
[ 89539-54-8 ]
[ 86-77-1 ]
[ 586345-77-9 ]

Reference： [1]Helvetica Chimica Acta,2003,vol. 86,p. 778 - 786

8
[ 86-77-1 ]
[ 375-72-4 ]
1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonic acid dibenzofuran-2-yl ester [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
99%	With triethylamine In acetonitrile at 20℃; for 18h;

Reference： [1]Botman, Peter N. M.; Fraanje, Jan; Goubitz, Kees; Peschar, Rene; Verhoeven, Jan W.; Van Maarseveen, Jan H.; Hiemstra, Henk [Advanced Synthesis and Catalysis, 2004, vol. 346, # 7, p. 743 - 754]

9
[ 1111-97-3 ]
[ 86-77-1 ]
[ 905294-06-6 ]

Yield	Reaction Conditions	Operation in experiment
85%	With 1,8-diazabicyclo[5.4.0]undec-7-ene In acetonitrile at 20℃; for 5h;
85%	With 1,8-diazabicyclo[5.4.0]undec-7-ene In acetonitrile at 0℃; for 5h; Cooling with ice-salt bath;	1.2.1 1.2 Synthesis and characteristics of obtained compounds 1.2.1 Preparation of 2-(1,1-dimethyl-propargyloxy)-dibenzofuran (5). To a solution of 2-hydroxydibenzofuran (4) (16.20 mmoles, 3 g) in anhydrous acetonitrile (6 mL, dried over 4A molecular sieve) under argon and cooled using an ice-salt bath were added DBU (16.20 mmol, 1.68 mL) and copper chloride dihydrate (0.20 mol, 3 mg) followed by the addition of chlorobutyne 3 (16.20 mmol, 2.50 mL). After stirring for 5 hours at 0°C, the mixture was concentrated at reduced pressure and the residue was partitioned between water (20 mL) and toluene (20 mL). The organic fraction was washed successively with hydrochloric acid 1N (20 mL), sodium hydroxide 1N (20 mL), 1N sodium hydrogenocarbonate (20 mL) and brine (20 mL) before being dried over anhydrous magnesium sulfate. After filtration, the solvent was then evaporated to dryness under reduced pressure to give compound 5 as a pale yellow oil (3.40 g, 85 %) which was used without further purification. IR (KBr) νmax cm-1 : 3299, 2992, 2918, 2358, 2334, 1593, 1481, 1444, 1175, 1137, 747. UV. λ nm (log Σ) in methanol: 211 (4.06), 251 (3.59), 287 (3.49) 1H (CDCl3): 7.98 (dd, 1H, J = 9, 2, H-9); 7.81 (d, 1H, J = 2, H-1), 7,60 (dd, 1H, J = 9, 2, H-6); 7.50 (d, 1H, J = 9, H-3); 7.48 (td, 1H, J = 9, 2, H-7); 7.35 (td, 1H, J = 9, 2, H-8); 7.33 (d, 1H, J = 9, H-4); 2.60 (s, CH.C), 1.53 (s, 3H, 2 x CH3). 13C (400 MHz, CDCl3) :157.2 (C2); 153.1 (C5a); 151.4 (C4a); 127.5 (C7); 124.8 (C9a); 124.7 (2C, C9 + C8); 121.1 (C6); 114.6 (C4); 112.1 (C1); 111.9 (C9b); 111.7 (C3); 86.6 (HC.C), 74.3 (HC.C), 73.82 (C(CH3)3), 30.0 (2C, CH3); m/z : = 251.[MH]+.

Reference： [1]Prado, Soizic; Ledeit, Herve; Michel, Sylvie; Koch, Michel; Darbord, Jacques Christian; Cole, Stewart T.; Tillequin, Francois; Brodin, Priscille [Bioorganic and Medicinal Chemistry, 2006, vol. 14, # 15, p. 5423 - 5428]
[2]Current Patent Assignee: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE; PARIS CITE UNIVERSITY; INSTITUT PASTEUR - EP1770089, 2007, A1 Location in patent: Page/Page column 14

10
[ 86-77-1 ]
[ 1619-34-7 ]
(+/-)-3-(dibenzofuran-2-yloxy)-1-azabicyclo[2.2.2]octane [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
29%	With triphenylphosphine; diethylazodicarboxylate In tetrahydrofuran at 20 - 50℃; for 168h;	G Method G; [(+)-3-(DIBENZOFURAN-2-VLOXV)-1-AZABICYCLOF2.] 2. 21octane fumaric acid salt (Compound G1) To a mixture of [()-3-QUINUCLIDINOL] (3.0 g, 23.6 [MMOL),] 2- hydroxydibenzofuran (4.3 g, 23.6 [MMOL),] triphenylphosphine (9.29 g, 35.4 [MMOL)] and THF, was added: diethylazodicarboxylate (6.3 [ML,] 35.4 [MMOL)] over a time period of 40 min at room temperature. The mixture was stirred at [50°C] for 7 days. Aqueous sodium hydroxide (100 [ML,] 1 M) was added. The mixture was extracted with [DICHLOROMETHANE] (3 x 100 [ML).] Chromatography on silica gel with [DICHLOROMETHANE,] methanol and [CONC.] ammonia (89: 10: 1) gave the title compound. Yield 2.0 g (29%). The corresponding fumaric acid salt was obtained by addition of a diethyl ether and methanol mixture (9: 1) saturated with fumaric acid. Mp [131.] 3-133. [8°C.] The compound also may be named [()-3- (DIBENZOFURAN-2-YLOXY)-] quinuclidine.

Reference： [1]Current Patent Assignee: NEUROSEARCH A/S - WO2004/16608, 2004, A1 Location in patent: Page 24

11
triethylorthoacrylate [ No CAS ]
[ 86-77-1 ]
[ 152609-74-0 ]

Yield	Reaction Conditions	Operation in experiment
5.67 g (67%)	With Trimethylacetic acid In toluene	1 3-[2-[3-[(5-Ethyl-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-1-dibenzofuran]propanoic acid disodium salt STR5 A. Preparation of 3,3-diethoxy-2,3-dihydro-1H-benzofuro-[3,2-f][1]benzopyran A solution of 2-hydroxydibenzofuran (5.00 g, 27.2 mmol), triethylorthoacrylate (10.1 g, 54.3 mmol) and pivalic acid (1.39 g, 13.6 mmol) in toluene (100 mL) was refluxed for 18 hours. The mixture was cooled to room temperature and washed once with water and once with a saturated sodium bicarbonate solution, dried over sodium sulfate, filtered and concentrated in vacuo to provide an orange oil. This material was diluted with hexane and maintained at -20° C. for 18 hours. The resulting crystals were collected via vacuum filtration to provide 5.67 g (67%) of the desired title intermediate, mp 64° C.; NMR (CDCl3) 7.96 (d, J=7.8 Hz, 1H), 7.57 (d, J=8.0 Hz, 1H), 7.46 (t, J=8 Hz, 1H), 7.35 (m, 2H), 7.06 (d, J=8.8 Hz, 1H), 3.82 (q, J=7.2 Hz, 2H), 3.73 (q, J=6.8 Hz, 2H), 3.35 (t, J=6.9 Hz, 2H), 2.29 (t, J=7.0 Hz, 2H), 1.23 (t, J=7.1 Hz, 6H); MS-FD m/e 312 (p); IR (CHCl3, cm-1) 2982, 1494, 1476, 1451, 1434, 1251, 1090, 1054, 975. Analysis for C19 H20 O4: Calc: C, 73.06; H, 6.45; Found: C, 72.81; H, 6.72.
5.67 g (67%)	With Trimethylacetic acid In toluene	1 EXAMPLE 1 EXAMPLE 1 3-[2-[3-[(5-Ethyl-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-1-dibenzofuran]propanoic acid disodium salt STR6 A. Preparation of 3,3-diethoxy-2,3-dihydro-1H-benzofuro-[3,2-f][1]benzopyran. A solution of 2-hydroxydibenzofuran (5.00 g, 27.2 mmol), triethylorthoacrylate (10.1 g, 54.3 mmol) and pivalic acid (1.39 g, 13.6 mmol) in toluene (100 mL) was refluxed for 18 hours. The mixture was cooled to room temperature and washed once with water and once with a saturated sodium bicarbonate solution, dried over sodium sulfate, filtered and concentrated in vacuo to provide an orange oil. This material was diluted with hexane and maintained at -20° C. for 18 hours. The resulting crystals were collected via vacuum filtration to provide 5.67 g (67%) of the desired title intermediate, mp 64° C.; NMR (CDCl3) 7.96 (d, J=7.8 Hz, 1H), 7.57 (d, J=8.0 Hz, 1H), 7.46 (t, J=8 Hz, 1H), 7.35 (m, 2H), 7.06 (d, J=8.8 Hz, 1H), 3.82 (q, J=7.2 Hz, 2H), 3.73 (q, J=6.8 Hz, 2H), 3.35 (t, J=6.9 Hz, 2H), 2.29 (t, J=7.0 Hz, 2H), 1.23 (t, J=7.1 Hz, 6H); MS-FD m/e 312 (p); IR (CHCl3, cm-1) 2982, 1494, 1476, 1451, 1434, 1251, 1090, 1054, 975. Analysis for C19 H20 O4: Calc: C, 73.06; H, 6.45; Found: C, 72.81; H, 6.72.
5.67 g (67%)	With Trimethylacetic acid In toluene	1.A 3-[2-[3-[(5-Ethyl-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-1-dibenzofuran]propanoic acid disodium salt STR5 A. Preparation of 3,3-diethoxy-2,3-dihydro-1H-benzofuro-[3,2-f][1]benzopyran. A solution of 2-hydroxydibenzofuran (5.00 g, 27.2 mmol), triethylorthoacrylate (10.1 g, 54.3 mmol) and pivalic acid (1.39 g, 13.6 mmol) in toluene (100 mL) was refluxed for 18 hours. The mixture was cooled to room temperature and washed once with water and once with a saturated sodium bicarbonate solution, dried over sodium sulfate, filtered and concentrated in vacuo to provide an orange oil. This material was diluted with hexane and maintained at -20° C. for 18 hours. The resulting crystals were collected via vacuum filtration to provide 5.67 g (67%) of the desired title intermediate, mp 64° C.; NMR (CDCl3) 7.96 (d, J=7.8 Hz, 1H), 7.57 (d, J=8.0 Hz, 1H), 7.46 (t, J=8 Hz, 1H), 7.35 (m, 2H), 7.06 (d, J=8.8 Hz, 1H), 3.82 (q, J=7.2 Hz, 2H), 3.73 (q, J=6.8 Hz, 2H), 3.35 (t, J=6.9 Hz, 2H), 2.29 (t, J=7.0 Hz, 2H), 1.23 (t, J=7.1 Hz, 6H); MS-FD m/e 312 (p); IR (CHCl3, cm-1) 2982, 1494, 1476, 1451, 1434, 1251, 1090, 1054, 975. Analysis for C19 H20 O4: Calc: C, 73.06; H, 6.45; Found: C, 72.81; H, 6.72.

5.67 g (67%)

With Trimethylacetic acid In toluene

1.A 3-[2-[3-[(5-Ethyl-2-hydroxy[1,1'-biphenyl]-4-yl)oxy]propoxy]-1-dibenzofuran]propanoic acid disodium salt STR5 A. Preparation of 3,3-diethoxy-2,3-dihydro-1H-benzofuro-[3,2-f][l]benzopyran. A solution of 2-hydroxydibenzofuran (5.00 g, 27.2 mmol), triethylorthoacrylate (10.1 g, 54.3 mmol) and pivalic acid (1.39 g, 13.6 mmol) in toluene (100 mL) was refluxed for 18 hours. The mixture was cooled to room temperature and washed once with water and once with a saturated sodium bicarbonate solution, dried over sodium sulfate, filtered and concentrated in vacuo to provide an orange oil. This material was diluted with hexane and maintained at -20° C. for 18 hours. The resulting crystals were collected via vacuum filtration to provide 5.67 g (67%) of the desired title intermediate, mp 64° C.; NMR (CDCl3) 7.96 (d, J=7.8 Hz, 1H), 7.57 (d, J=8.0 Hz, 1H), 7.46 (t, J=8 Hz, 1H), 7.35 (m, 2H), 7.06 (d, J=8.8 Hz, 1H), 3.82 (q, J=7.2 Hz, 2H), 3.73 (q, J=6.8 Hz, 2H), 3.35 (t, J=6.9 Hz, 2H), 2.29 (t, J=7.0 Hz, 2H), 1.23 (t, J=7.1 Hz, 6H); MS-FD m/e 312 (p); IR (CHCl3, cm-1) 2982, 1494, 1476, 1451, 1434, 1251, 1090, 1054, 975. Analysis for C19 H20 O4: Calc: C, 73.06; H, 6.45; Found: C, 72.81; H, 6.72.

Reference： [1]Current Patent Assignee: ELI LILLY & CO - US5910505, 1999, A
[2]Current Patent Assignee: ELI LILLY & CO - US5914340, 1999, A
[3]Current Patent Assignee: ELI LILLY & CO - US5998454, 1999, A
[4]Current Patent Assignee: ELI LILLY & CO - US5817684, 1998, A

12
[ 543-82-8 ]
[ 86-77-1 ]
[ 503-38-8 ]
[ 165730-21-2 ]

Yield	Reaction Conditions	Operation in experiment
4.27 g (46%)	With pyridine; 2,3-Dimethylaniline In 1,4-dioxane; benzene	2 (1.5-Dimethylhexyl) carbamic acid 2-dibenzofuranyl ester EXAMPLE 2 (1.5-Dimethylhexyl) carbamic acid 2-dibenzofuranyl ester A solution of 2-hydroxydibenzofuran (5.0 g, 27 mmol) and dimethylaniline (3.4 mL, 27 mmol) in 35 mL of benzene plus 1.5 mL of dioxane was added dropwise under nitrogen to a solution of trichloromethyl chloroformate (1.6 mL, 14 mmol) in 30 mL of benzene at ice bath temperature. After the addition the cooling bath was removed and the stirring continued for approximately 24 hours. The reaction was cooled to ice bath temperature and a solution of 1,5-dimethylhexylamine (4.6 mL, 27 mmol) and pyridine (4.4 mL, 54 mmol) in 30 mL of benzene was added dropwise over 15 minutes. After the addition the reaction was stirred at ice bath temperature for 2 hours. The cooling bath was removed and the stirring continued for approximately 22 hours. The reaction was extracted two times with 1N HCl. The organic solution was dried over anhydrous MgSO4 and the solvent removed under reduced pressure to give 6.19 g of a yellow solid. Recrystallization from isopropanol gave 4.27 g (46%) of the title compound as a yellow crystalline solid, mp 114°-115° C. Elemental analysis for C21 H25 NO3 Calc'd: C, 74.31; H, 7.42; N, 4.13 Found: C, 74.22; H, 7.50; N, 3.98

Reference： [1]Current Patent Assignee: PFIZER INC - US5401769, 1995, A

13
[ 872-50-4 ]
[ 86-77-1 ]
Cs₂ CO₃ [ No CAS ]
[ 7462-74-0 ]
N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	With 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone; NaH; In 1,4-dioxane;	EXAMPLE 4 Preparation of N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide To a solution of 2-hydroxydibenzofuran (682 mg, 3.70 mmol) in dioxane (20 mL) was added NaH (Aldrich, dry, 300 mg, 12.2 mmol) and Cs2 CO3 (4.00 g, 12.2 mmol). The resulting mixture was stirred at room temperature for about 30 minutes, then 2-bromo-2-methyl-propanamide (2.03 g, 12.2 mmol) was added and the resulting mixture was stirred at reflux for 18 h. After the reflux period, NMP (20 mL), DMPU (2 mL), and NaH (Aldrich, dry, 100 mg, 4.07 mmol) were added. The resulting mixture was stirred at 150 C. for 72 h. The reaction was cooled to room temp., and partitioned between water (50 mL) and EtOAc (100 mL). The aqueous layer was extracted with EtOAc (100 mL) and the combined organics washed with water (2*50 mL), dried (Na2 SO4), and concentrated to about 3 g of material. The brown oil was chromatographed on silica (200 mL, 4 cm diam. column), eluding with 3:7 EtOAc/hexane to obtain N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide as an off-white solid (580 mg, 2.15 mmol, 58.1% yield). This was recrystallized from toluene for an analytical sample: mp 134-137 C. 1 H NMR (300 MHz, CDCl3) delta 8.83 (br s, 1H, N--H), 8.41 (d, 1H, C1 --H, J=2.34 Hz), 7.92 (m, 1H, Ar--H), 7.56-7.29 (om's, 5H, Ar--H), 2.46 (br s, 1H, O--H), 1.60 (s, 6H, C(CH3)2); 13 C NMR (75 MHz, CDCl3) delta 174.2, 156.8, 152.9, 132.8, 127.3, 124.6, 124.2, 122.7, 120.8, 119.5, 112.0, 111.7, 74.3, 28.0; IR (KBr pellet) 1651, 1668 (amide C=O stretches), 3364 (NH stretch), 3383 (OH stretch); MS (EI) 269; Analysis: Calculated C 71.36 H 5.61 N 5.20 Found C 71.43 H 5.58 N 5.06.

Reference： [1]Patent: US5817874,1998,A

14
[ 872-50-4 ]
[ 86-77-1 ]
[ 7462-74-0 ]
N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
	With 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone; NaH; caesium carbonate; In 1,4-dioxane;	Example 4 Preparation of N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide To a solution of 2-hydroxydibenzofuran (682 mg, 3.70 mmol) in dioxane (20 mL) was added NaH (Aldrich, dry, 300 mg, 12.2 mmol) and Cs2CO3 (4.00 g, 12.2 mmol). The resulting mixture was stirred at room temperature for about 30 minutes, then 2-bromo-2-methyl-propanamide (2.03 g, 12.2 mmol) was added and the resulting mixture was stirred at reflux for 18 h. After the reflux period, NMP (20 mL), DMPU (2 mL), and NaH (Aldrich, dry, 100 mg, 4.07 mmol) were added. The resulting mixture was stirred at 150 C for 72 h. The reaction was cooled to room temp., and partitioned between water (50 mL) and EtOAc (100 mL). The aqueous layer was extracted with EtOAc (100 mL) and the combined organics washed with water (2 x 50 mL), dried (Na2SO4), and concentrated to about 3 g of material. The brown oil was chromatographed on silica (200 mL, 4 cm diam. column), eluding with 3:7 EtOAc/hexane to obtain N-(2-dibenzofuranyl)-2-hydroxy-2-methylpropionamide as an off-white solid (580 mg, 2.15 mmol, 58.1% yield). This was recrystallized from toluene for an analytical sample: mp 134-137 C. 1H NMR (300 MHz, CDCl3) delta 8.83 (br s, 1 H, N-H), 8.41 (d, 1 H, C1-H, J = 2.34 Hz), 7.92 (m, 1 H, Ar-H), 7.56-7.29 (om's, 5 H, Ar-H), 2.46 (br s, 1 H, O-H), 1.60 (s, 6 H, C(CH3)2); 13C NMR (75 MHz, CDCl3) delta 174.2, 156.8, 152.9, 132.8, 127.3, 124.6, 124.2, 122.7, 120.8, 119.5, 112.0, 111.7, 74.3, 28.0; IR (KBr pellet) 1651, 1668 (amide C=O stretches), 3364 (NH stretch), 3383 (OH stretch); MS (EI) 269; Analysis: Calculated C 71.36 H 5.61 N 5.20 Found C 71.43 H 5.58 N 5.06.

Reference： [1]Patent: EP888380,2001,B1

15
[ 86-77-1 ]
[ 100108-01-8 ]
[ 889660-63-3 ]

Yield	Reaction Conditions	Operation in experiment
	Stage #1: 2-hydroxydibenzofuran With sodium hydride In N,N-dimethyl-formamide at 20℃; for 3.91667h; Stage #2: ethyl 2-bromo-2-methylthio-acetate In N,N-dimethyl-formamide at 20 - 47℃; for 21.8333h;	1.2 Stage 2: Preparation of ethyl 2-(dibenzofuranyl-2-oxy)-2-methylthioacetate; To a stirred suspension of sodium hydride (6.6g, 80% dispersion in mineral oil) in dry N,N-dimethylfbrmamide (25ml) under an atmosphere of nitrogen at ambient temperature was added a solution of 2-hydroxydibenzofuran (36.8g) in N,iV-dimethyl- formamide (150ml) over 40 minutes. The mixture was stirred for 3.25 hours then a solution of ethyl 2-bromo-2-methylthioacetate (54.2g, 90% purity) in N, JV-dimethyl- formamide (50ml) was added dropwise over 20 minutes during which time the reaction temperature was allowed to rise to 470C. On complete addition, the mixture was stirred for 21.5 hours, poured into water and extracted with diethyl ether (three times). The extracts were combined, washed with dilute aqueous sodium hydroxide (twice), water (three times) then dried over magnesium sulfate and evaporated under reduced pressure. The residue was fractionated by chromatography (silica; diethyl ether: hexane, 1:2 to 1:1 EPO by volume) to give an orange oil, 33g, containing the required product that was used in the next stage without further purification. A sample of the oil was further purified by chromatography to provide an analytical sample.1H NMR (CDCl3) δ ppm: 1.34-1.38 (3H,t); 2.26 (3H,s); 4.30-4.38 (2H,m); 5.64(lH,s) 7.16-7.20(lH,dd); 7.32-7.36(lH,dd); 7.44-7.60(4H,m); 7.92-7.94(lH,d).
	Stage #1: 2-hydroxydibenzofuran With sodium hydride In N,N-dimethyl-formamide at 20℃; for 3.91667h; Stage #2: ethyl 2-bromo-2-methylthio-acetate In N,N-dimethyl-formamide at 20 - 47℃; for 21.8333h;	12.1 EXAMPLE 12; This Example illustrates the preparation of 2-(dibenzofuranyl-2-oxy)-2-methylthio-N-(2- methylprop-2-yl) acetamide (Compound No. 12 of Table 50); Step 1: Preparation of ethyl 2-(dibenzofuranyl-2-oxy)-2-methylthioacetate; To a stirred suspension of sodium hydride (6.6g, 80% dispersion in mineral oil) in dry ΛζN-dimethylformamide (25ml) under an atmosphere of nitrogen at ambient temperature was added a solution of 2-hydroxydibenzofuran (36.8g) in JV,iV-diinethyl- formamide (150ml) over 40 minutes. The mixture was stirred for 3.25 hours then a solution of ethyl 2-bromo-2-methylthioacetate (54.2g, 90% purity) in ΛζiV-dimethyl- formamide (50ml) was added dropwise over 20 minutes during which time the reaction temperature was allowed to rise to 470C. On complete addition, the mixture was stirred for 21.5 hours, poured into water and extracted with diethyl ether (three times). The extracts were combined, washed with dilute aqueous sodium hydroxide (twice), water EPO (three times) then dried over magnesium sulfate and evaporated under reduced pressure. The residue was fractionated by chromatography (silica; diethyl ether: hexane, 1:2 to 1:1 by volume) to give an orange oil, 33g, containing the required product that was used in the next Stage without further purification. A sample of the oil was further purified by chromatography to provide an analytical sample.1H NMR (CDCl3) δ ppm: 1.34-1.38 (3H,t); 2.26 (3H,s); 4.30-4.38 (2H,m); 5.64(lH,s) 7.16-7.20(lH,dd); 7.32-7.36(lH,dd); 7.44-7.60(4H,m); 7.92-7.94(lH,d).

Reference： [1]Current Patent Assignee: SINOCHEM HOLDINGS CORPORATION LTD; Syngenta (in: Sinochem Holdings) - WO2006/58699, 2006, A1 Location in patent: Page/Page column 35-36
[2]Current Patent Assignee: Syngenta (in: Sinochem Holdings); SINOCHEM HOLDINGS CORPORATION LTD - WO2006/58700, 2006, A1 Location in patent: Page/Page column 93-94

16
[ 4746-97-8 ]
[ 6092-80-4 ]
[ 86-77-1 ]

Reference： [1]Synlett,2009,p. 3003 - 3006

17
[ 60-35-5 ]
[ 86-77-1 ]
[ 104-88-1 ]
[ 1228443-51-3 ]

Yield	Reaction Conditions	Operation in experiment
96%	With stannous chloride dihydrate at 125℃; for 3.5h;
96%	With tin(II) chloride dihdyrate at 125℃; for 3.5h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

18
[ 60-35-5 ]
[ 86-77-1 ]
[ 86-81-7 ]
[ 1228443-54-6 ]

Yield	Reaction Conditions	Operation in experiment
85%	With stannous chloride dihydrate at 125℃; for 6h;
78%	With polyphosphoric acid supported silica at 125℃; for 4h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

19
[ 60-35-5 ]
[ 86-77-1 ]
[ 100-52-7 ]
[ 1228443-50-2 ]

Yield	Reaction Conditions	Operation in experiment
82%	With polyphosphoric acid supported silica at 125℃; for 3h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.
80%	With stannous chloride dihydrate at 125℃; for 4.5h;

Reference： [1]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]
[2]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]

20
[ 60-35-5 ]
[ 86-77-1 ]
[ 123-11-5 ]
[ 1228443-59-1 ]

Yield	Reaction Conditions	Operation in experiment
88%	With stannous chloride dihydrate at 125℃; for 5h;
88%	With polyphosphoric acid supported silica at 125℃; for 4h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

21
[ 86-77-1 ]
[ 104-88-1 ]
[ 55-21-0 ]
[ 1228443-53-5 ]

Yield	Reaction Conditions	Operation in experiment
91%	With stannous chloride dihydrate at 125℃; for 3.5h;
88%	With polyphosphoric acid supported silica at 125℃; for 2.5h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

22
[ 86-77-1 ]
[ 104-88-1 ]
[ 57-13-6 ]
[ 1228443-64-8 ]

Yield	Reaction Conditions	Operation in experiment
95%	With stannous chloride dihydrate at 160℃; for 2.5h;
90%	With polyphosphoric acid supported silica at 160℃;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

23
[ 86-77-1 ]
[ 104-88-1 ]
[ 57-13-6 ]
[ 1228443-52-4 ]

Yield	Reaction Conditions	Operation in experiment
93%	With stannous chloride dihydrate at 125℃; for 3.5h;
85%	With polyphosphoric acid supported silica at 125℃; for 3h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

24
[ 86-77-1 ]
[ 55-21-0 ]
[ 86-81-7 ]
[ 1228443-55-7 ]

Yield	Reaction Conditions	Operation in experiment
82%	With stannous chloride dihydrate at 125℃; for 6h;
75%	With polyphosphoric acid supported silica at 125℃; for 4h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

25
[ 86-77-1 ]
[ 86-81-7 ]
[ 57-13-6 ]
[ 1228443-56-8 ]

Yield	Reaction Conditions	Operation in experiment
85%	With stannous chloride dihydrate at 125℃; for 6h;
76%	With polyphosphoric acid supported silica at 125℃; for 4h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

26
[ 86-77-1 ]
[ 86-81-7 ]
[ 57-13-6 ]
[ 1228443-68-2 ]

Yield	Reaction Conditions	Operation in experiment
85%	With stannous chloride dihydrate at 160℃; for 4h;
76%	With polyphosphoric acid supported silica at 160℃;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

27
[ 86-77-1 ]
[ 123-11-5 ]
[ 57-13-6 ]
[ 1228443-60-4 ]

Yield	Reaction Conditions	Operation in experiment
83%	With stannous chloride dihydrate at 125℃; for 5h;
80%	With polyphosphoric acid supported silica at 125℃; for 3.5h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

28
[ 86-77-1 ]
[ 123-11-5 ]
[ 57-13-6 ]
[ 1228443-67-1 ]

Yield	Reaction Conditions	Operation in experiment
89%	With stannous chloride dihydrate at 160℃; for 3h;
81%	With polyphosphoric acid supported silica at 160℃;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

29
[ 86-77-1 ]
[ 1122-91-4 ]
[ 57-13-6 ]
[ 1228443-57-9 ]

Yield	Reaction Conditions	Operation in experiment
90%	With stannous chloride dihydrate at 125℃; for 4h;
84%	With polyphosphoric acid supported silica at 125℃; for 3h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

30
[ 86-77-1 ]
[ 1122-91-4 ]
[ 57-13-6 ]
[ 1228443-65-9 ]

Yield	Reaction Conditions	Operation in experiment
92%	With stannous chloride dihydrate at 160℃; for 3h;
90%	With polyphosphoric acid supported silica at 160℃;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Location in patent: experimental part Kantevari, Srinivas; Yempala, Thirumal; Vuppalapati, Srinivasu V. N. [Synthesis, 2010, # 6, p. 959 - 966]
[2]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

31
[ 33094-66-5 ]
[ 54125-02-9 ]
[ 86-77-1 ]

Yield	Reaction Conditions	Operation in experiment
80%	In benzene at 140℃; for 72h; Cooling with liquid nitrogen; sealed;	General Procedure for the thermal reactions of nitrobenzofurans. The temperature, the length of the reaction, and the diene/dienophile ratio were dependent on the starting material and are indicated in [Table 1] and [Table 2]. An ampule containing a solution of 1.0 mmol of the dienophile and the required amount of diene in 0.5 ml of dry benzene was cooled in liquid nitrogen, sealed, and then heated in an oil bath. After the reaction time was completed, it was cooled once more in liquid nitrogen and opened. The solution was evaporated and the residue purified by column chromatography on silica gel or alumina using hexane/ethyl acetate mixtures as eluent.[Table 1] and [Table 2]. An ampule containing a solution of 1.0 mmol of the dienophile and the required amount of diene in 0.5 ml of dry benzene was cooled in liquid nitrogen, sealed, and then heated in an oil bath. After the reaction time was completed, it was cooled once more in liquid nitrogen and opened. The solution was evaporated and the residue purified by column chromatography on silica gel or alumina using hexane/ethyl acetate mixtures as eluent.

Reference： [1]Location in patent: scheme or table Della Rosa, Claudia D.; Sanchez, Juan P.; Kneeteman, María N.; Mancini, Pedro M.E. [Tetrahedron Letters, 2011, vol. 52, # 18, p. 2316 - 2319]

32
[ 60-35-5 ]
[ 86-77-1 ]
[ 1122-91-4 ]
[ 1318220-53-9 ]

Yield	Reaction Conditions	Operation in experiment
90%	With polyphosphoric acid supported silica at 125℃; for 3h;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.
70%	With barium phosphate In neat (no solvent) at 100℃; for 24h;	2.3 General procedure General procedure: To a mixture of aromatic aldehyde (1 mmol), 2-naphthol/dibenzofuran-2-ol (1 mmol) and acetamide/bezamide/urea (1.3 mmol) was added Ba3(PO4)2 nano-particles (0.1 mmol), and the mixture was heated at 100 °C in an oil bath for the appropriate time. The progress of the reaction was monitored by TLC. After completion of the reaction, mass was cooled to 25 °C and the mixture was dissolved in pure acetone. The catalyst was removed by simple filtration. The solvent was evaporated and the solid product was purified by recrystallization from ethanol.

Reference： [1]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]
[2]Taghrir, Hadi; Ghashang, Majid; Biregan, Mohammad Najafi [Chinese Chemical Letters, 2016, vol. 27, # 1, p. 119 - 126]

33
[ 86-77-1 ]
[ 100-52-7 ]
[ 57-13-6 ]
[ 1318220-59-5 ]

Yield	Reaction Conditions	Operation in experiment
85%	With polyphosphoric acid supported silica at 160℃;	General experimental procedure for the synthesis of amidoalkyl dibenzofuranols 5a-k and 1H-benzo[2,3]benzofuro[4,5-e][1,3]oxazin-3(2H)-ones 6a-e: General Procedure: A mixture of 2-dibenzofuranol 3 (1 mmol), aldehyde (1 mmol) amide or urea (1 mmol) and polyphosphoric acid supported silica (20 mol %) was heated at 125 °C with stirring for the time specified in table-2. After completion of reaction (TLC), it was cooled to room temperature and ethyl acetate (20 ml) was added. The catalyst was filtered; washed with hot ethyl acetate (3x 5 ml), the combined solvent was concentrated under reduced pressure. The gummy residue obtained was purified over silica gel column chromatography (Hexane; Ethyl acetate 1:1) to yield 5a-k as white crystalline solids.; For the synthesis of 6a-e; the reaction mixture was heated at 160 °C instead of 125 °C with stirring for the time specified in table-3. Column chromatography over silica eluting with hexane; ethyl acetate 3:2 yielded 6a-e as white or pale yellow solids.

Reference： [1]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]

34
[ 13761-32-5 ]
[ 86-77-1 ]

Yield	Reaction Conditions	Operation in experiment
79%	Stage #1: 2-acetyldibenzofuran With 3-chloro-benzenecarboperoxoic acid; trifluoroacetic acid In dichloromethane at 0 - 20℃; Stage #2: With hydrogenchloride; sodium methylate In methanol; water at 20℃;
77%	Stage #1: 2-acetyldibenzofuran With 3-chloro-benzenecarboperoxoic acid; trifluoroacetic acid In dichloromethane at 0 - 20℃; for 72h; Stage #2: With sodium methylate In methanol at 20℃; for 1h;
	Multi-step reaction with 2 steps 1: 3-chloro-benzenecarboperoxoic acid; trifluoroacetic acid / dichloromethane / 72 h / 0 - 20 °C 2: sodium methylate / methanol / 0.33 h / 20 °C

	Multi-step reaction with 2 steps 1: trifluoroacetic acid; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 72 h / 0 - 20 °C 2: methanol; sodium methylate / 0.33 h / 20 °C
	Multi-step reaction with 2 steps 1: trifluoroacetic acid; 3-chloro-benzenecarboperoxoic acid / dichloromethane / 72 h / 0 - 20 °C 2: sodium methylate / methanol / 20 °C / Inert atmosphere

Reference： [1]Chiranjeevi, Barreddi; Koyyada, Ganesh; Prabusreenivasan; Kumar, Vanaja; Sujitha, Pombala; Kumar, C. Ganesh; Sridhar; Shaik, Saida; Chandrasekharam, Malapaka [RSC Advances, 2013, vol. 3, # 37, p. 16475 - 16485]
[2]Purtsas, Alexander; Kataeva, Olga; Knölker, Hans-Joachim [Chemistry - A European Journal, 2020, vol. 26, # 11, p. 2499 - 2508]
[3]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]
[4]Current Patent Assignee: SHENZHEN CHIPSCREEN BIOSCIENCES CO LTD - CN108203438, 2018, A
[5]Chen, Weiming; Xu, Xiaoling; Sun, Mingfeng; Huang, Xuelong; Ma, Weiping; Jiang, Feng [Heterocycles, 2021, vol. 102, # 1, p. 122 - 128]

35
[ 20928-01-2 ]
[ 86-77-1 ]

Yield	Reaction Conditions	Operation in experiment
	Stage #1: dibenzo[b,d]furan-2-yl acetate With sodium methylate In methanol at 20℃; for 0.333333h; Stage #2: With hydrogenchloride In methanol; water	Experimental procedure for the synthesis of 2-dibenzofuranol 3 To a solution of dibenzofuran 1 (5.0 g, 29 mmol) in chloroform (50 mL), was added a mixture of AlCl3 (4.755 g, 35.6 mmol) and acetyl chloride (2.79 g, 35.6 mmol) in chloroform (50 mL). After stirring the reaction mixture for 45 min at room temperature, it was poured into ice water (100 mL) and 1N HCl (50 mL,). The aqueous layer was washed with chloroform (2 x 30 mL), combined organic layer was dried over anhyd. Na2SO4 and concentrated under vacuum. The crude residue was purified over silica gel column chromatography to yield 2-acetyldibezofuran 2 (5.90 g, 95%) as white solid. Compound 2 was fully characterized by IR, NMR and Mass spectral data and was compared with the authentic sample.; 2-Acetyldibezofuran 2 (1.0g, 4.7 mmol) in CH2Cl2 (20 mL) at 0 °C was added trifluoroacetic acid (1.90 mL, 14.1 mmol) and mCPBA (0.89 g, 5.2 mmol) slowly at 0 °C . After stirring at room temperature for 3 days, the reaction mixture was quenched with ferrous sulphate, washed with water; organic layer was separated, dried over anhyd. Na2SO4 and concentrated over rotary evaporator. The crude residue was dissolved in methanol (15 mL), sodium methoxide (0.76 g, 14.1 mmol) was added and stirred at RT for 20 min. The reaction mixture was quenched with 2N HCl (5 mL) and solvent was removed under vacuum. It was then treated with water, extracted with chloroform (2 x 30 mL), combined organic layers was dried over anhyd. Na2SO4 and concentrated under vacuum. Purification of residue over silica gel column chromatography yielded compound 2-dibenzofuranol 3 (0.69 g, 80%) as pale yellow solid. mp: 128 °C .IR (KBr): 3108(br), 2925, 1596, 1446, 1362, 1167,810 cm-1. 1H NMR (300 MHz, CDCl3) δ 7.84 (d, J = 7.5 Hz, 1H), 7.50 (d, J = 8.3 Hz, 1H), 7.44-7.34 (m, 2H), 7.33-7.23 (m, 2H) ,6.90 (dd, J=3.0 and 9.0 Hz, 1H), 4.60 (s, 1H). 13C NMR (75MHz,CDCl3) δ=156.9, 151.3, 127.2, 125.8, 125.0, 124.1, 122.4, 120.6, 115.2,112.0,111.6,106.2 . MS (EI-MS): m/z for C12H7O2 :184 [M+].
3.6 g	With methanol; sodium methylate at 20℃; for 0.333333h;	53 Preparation of 2-hydroxydibenzo[b,d]furan The crude dibenzo[b,d]furan-2-acetate was dissolved in methanol (100 mL) and sodium methoxide (4 g, 75 mmol) was added.The reaction was then stirred at room temperature for 20 min.The reaction mixture was quenched with EtOAc EtOAc (EtOAc) Ether/ethyl acetate = 10/1 eluent was purified by column.Obtained a grayish yellow solid2-Hydroxydibenzo[b,d]furan (3.6 g, 78%).
	With sodium methylate In methanol at 20℃; Inert atmosphere;	1 Add 130 g of the crude compound of formula V to the reaction flask, add 650 ml of methanol and stir evenly, add 46.5 g of sodium methoxide, under nitrogen protection, and stir at room temperature until the reaction is complete. 2mol/L hydrochloric acid was added dropwise to quench the temperature at 15°C, the pH of the system was adjusted to about 4, and the concentration was extracted with dichloromethane and water. The organic phase was concentrated to obtain 124g of the crude compound of formula IV, which was sent to the next step without purification.

With sodium methylate In methanol at 20℃; Inert atmosphere;

Preparation of 8-hydroxydibenzo[b,d]furan-4-carbaldehyde 14 Under nitrogen atmosphere, 100 g intermediate 18 (0.44 mol, 1.0 equiv.) and 35.8 g sodium methoxide (0.66 mol, 1.5 equiv.) were added into 500 mL MeOH. The reaction was stopped after stirred overnight and monitored by TLC. Below 15 °C, dilute hydrochloric acid (2 mol/L) was added to adjust pH value to 4. The resulting solution was concentrated and extracted with DCM and water. The organic phase was washed with water and brine, and dried over anhydrous Na2SO4. After filtration and concentration, crude 77.4 g intermediate 16 was obtained as a yellow solid, which was not stable in air atmosphere and used directly for next step.

Reference： [1]Kantevari, Srinivas; Yempala, Thirumal; Yogeeswari, Perumal; Sriram, Dharmarajan; Sridhar, Balasubramanian [Bioorganic and Medicinal Chemistry Letters, 2011, vol. 21, # 14, p. 4316 - 4319]
[2]Current Patent Assignee: SHENZHEN CHIPSCREEN BIOSCIENCES CO LTD - CN108203438, 2018, A Location in patent: Paragraph 0415-0418
[3]Current Patent Assignee: SHANGHAI AIYI TECH - CN111646961, 2020, A Location in patent: Paragraph 0033-0036; 0039
[4]Chen, Weiming; Xu, Xiaoling; Sun, Mingfeng; Huang, Xuelong; Ma, Weiping; Jiang, Feng [Heterocycles, 2021, vol. 102, # 1, p. 122 - 128]

36
[ 86-77-1 ]
[ 51079-04-0 ]

Yield	Reaction Conditions	Operation in experiment
85%	With hydrogenchloride; iodine chloride; glacial acetic acid In lithium hydroxide monohydrate at 20℃; for 24h; regioselective reaction;	13. Preparation of 1-iododibenzo[b,d]furan-2-ol 9: To a solution of dibenzo[b,d]furan-2-ol 8 (3.1 g, 16.8 mmol) in acetic acid (20 mL) was added a solution of iodine monochloride (3.23 g, 16.8 mmol) in concd HCl (4 mL) and acetic acid (7 mL) and stirred at room temperature for 24 h. After completion of reaction, water (100 mL) was poured into the reaction mixture, solid precipitate was filtered, washed twice with water (20 mL) and dried under vacuum. Recrystalization of the solid from methanol gave pure 1-iododibenzo[b,d]furan-2-ol 9 (4.4 g, 85%) as light brown solid. mp 128 C; 1H NMR (300 MHz, CDCl3) d 8.60(d, J = 7.7 Hz, 1H), 7.56-7.31(m, 4H), 7.11 (d,J = 8.8 Hz, 1H), 5.32(br s, 1H). 13C NMR (75 MHz, CDCl3+DMSO) d 155.9, 151.8, 149.2, 126.7, 126.1, 124.5, 120.7, 120.6, 113.2, 110.6, 110.6, 74.8. IR (KBr) 3262, 1852, 1620, 1571, 1450, 1418, 1385, 1210, 1051, 808, 747 cm1. MS-EI Calcd for C12H7O2 310. Found: [M]+ = 310(100%).
75%	With hydrogenchloride; iodine chloride; glacial acetic acid In lithium hydroxide monohydrate at 20℃; for 24h;	4 Synthesis of Intermediate D-1 2-Hydroxydibenzo[b,d]furan (15.0 g, 81.4 mmol) and acetic acid (100 mL) were added to a three-necked flask, to which iodine monochloride (4.5 mL, 89.6 mmol), conc. HCl (55 mL) and acetic acid solution (34 mL) were added dropwise and then stirred at room temperature for 24 hours. After completion of the reaction, H2O (300 mL) was added thereto, and the produced precipitate was filtered and washed with H2O. The filtered solid was recrystallized from MeOH to give Intermediate D-1 (18.9 g, yield: 75%).MS[M+H]+=310
72%	With iodine chloride; glacial acetic acid at 100℃; for 4h;	1.1 1. Synthesis of Compound A-1 2-dibenzo [b, d] furanol (50 g, 271.7 mmol) was dissolved in AcOH (100 ml) and monohydrate (48.4 g, 298.9 mmol) was added thereto and stirred at 100 ° C for 4 hours.After the reaction was completed, the reaction mixture was cooled to room temperature, filtered, and the organic layer was separated from the filtrate. The organic layer was dried over magnesium sulfate, distilled under reduced pressure, and recrystallized from ethanol. The resulting solid was dried to obtain Compound A-1 (60.6 g, 72% .:

72%	With iodine chloride; glacial acetic acid at 100℃; for 4h;	1.1 1) Synthesis of Intermediate A-1 After dissolving 2-dibenzo[b,d]furanol (50 g, 271.7 mmol) in AcOH (100 ml), iodine monochloride (48.4 g, 298.9 mmol) was introduced thereto, and the result was stirred for 4 hours at approximately 100° C. After the reaction was finished, the result was cooled to room temperature, filtered, and an organic layer was separated from the filtrate. The organic layer was dried with magnesium sulfate, vacuum distilled and then recrystallized with ethanol to obtain solids, and the solids were dried to obtain Intermediate A-1 (60.6 g, yield: 72%). MS[M]=309.9
70%	With iodine chloride; glacial acetic acid at 100℃; for 4h;	1.1 (1) Synthesis of Compound A-1 2-Dibenzo [b, d] furanol (50 g, 271.7 mmol) was dissolved in AcOH (100 ml), iodine monochloride (48.4 g, 298.9 mmol) was added, and the mixture was stirred at about 100 ° C for 4 hours. After the reaction was completed, cooled to room temperature, filtered, the organic layer was separated from the filtrate, the organic layer was dried over magnesium sulfate, distilled under reduced pressure, and recrystallized with ethanol to dry the obtained solid, and then Compound A-1 (58.9g, 70%) was obtained.
61%	With hydrogenchloride; iodine chloride; glacial acetic acid In lithium hydroxide monohydrate at 20℃; for 24h;	1.1 1) Preparation of Compound 2-1 Dibenzo [b, d] furan-2-ol (150 g, 814.37 mmol)Was dissolved in 900 ml of acetic acidAfter dissolving, iodine monochloride (132.22 g, 814.37 mmol),195 ml of HCl, and 345 ml of acetic acid were added, and the mixture was stirred at room temperature for 24 hours. After completion of the reaction, 3 L of water was added to the reaction solution, and the solid was filtered and recrystallized with toluene (toluene) to obtain Compound 2-1 (155 g, 61%).

Reference： [1]Yempala, Thirumal; Sridevi, Jonnalagadda Padma; Yogeeswari, Perumal; Sriram, Darmarajan; Kantevari, Srinivas [Bioorganic and Medicinal Chemistry Letters, 2013, vol. 23, # 19, p. 5393 - 5396]
[2]Current Patent Assignee: LG CHEM CO.,LTD. - US2022/56048, 2022, A1 Location in patent: Paragraph 0120-0122
[3]Current Patent Assignee: LG CHEM CO.,LTD. - KR2019/42439, 2019, A Location in patent: Paragraph 0161-0164
[4]Current Patent Assignee: LG CHEM CO.,LTD. - US11367838, 2022, B2 Location in patent: Page/Page column 81; 89-90
[5]Current Patent Assignee: LG CHEM CO.,LTD. - KR2019/140747, 2019, A Location in patent: Paragraph 0168-0171
[6]Current Patent Assignee: LT SAMBO CO LTD - KR2019/13139, 2019, A Location in patent: Paragraph 0192-0195

37
[ 5397-82-0 ]
[ 86-77-1 ]

Yield	Reaction Conditions	Operation in experiment
92%	With 3-chloro-benzenecarboperoxoic acid; potassium hydroxide In methanol; dichloromethane
	Multi-step reaction with 2 steps 1: 3-chloro-benzenecarboperoxoic acid / dichloromethane / 12 h / 0 - 20 °C 2: potassium hydroxide / methanol / 2 h / 20 °C

Reference： [1]Yempala, Thirumal; Cassels, Bruce K. [Research on Chemical Intermediates, 2017, vol. 43, # 3, p. 1291 - 1299]
[2]Yempala, Thirumal; Sridevi, Jonnalagadda Padma; Yogeeswari, Perumal; Sriram, Darmarajan; Kantevari, Srinivas [Bioorganic and Medicinal Chemistry Letters, 2013, vol. 23, # 19, p. 5393 - 5396]

38
C₁₃H₈O₃ [ No CAS ]
[ 86-77-1 ]

Yield	Reaction Conditions	Operation in experiment
2.1 g	With potassium hydroxide In methanol at 20℃; for 2h;	12. Preparation of dibenzo[b,d]furan-2-ol 8: To a solution of dibenzo[b,d]furan-2-carbaldehyde 7 (2.5 g, 12.7 mmol) in CH2Cl2 (35 mL) at 0 °C, m-CPBA (2.63 g, 15.3 mmol) was added slowly at 0 °C. After stirring at room temperature for 12 h, the reaction mixture was quenched with ferrous sulphate, washed with water (20 mL) and saturated sodium bicarbonate (20 mL), the organic layer was separated, dried over anhydrous Na2SO4 and concentrated under reduced pressure. The crude residue was dissolved in methanol (35 mL), 7 mL of 10% KOH was added and stirred at rt for 2 h. The reaction mixture was quenched with 2 N HCl (15 mL) and solvent was removed under vacuum. The residue thus obtained was treated with water, extracted with chloroform (2 30 mL), combined organic layers was dried over anhydrous Na2SO4 and concentrated nder vacuum. Purification of crude residue over silica gel column hromatography yielded dibenzofuran-2-ol 8 (2.1 g, 92%) as pale yellow solid. The product obtained was fully characterized by spectra data and compared with authentic sample. Mp 126 C (lit.11 mp 125-128 °C).

Reference： [1]Yempala, Thirumal; Sridevi, Jonnalagadda Padma; Yogeeswari, Perumal; Sriram, Darmarajan; Kantevari, Srinivas [Bioorganic and Medicinal Chemistry Letters, 2013, vol. 23, # 19, p. 5393 - 5396]

39
[ 86-77-1 ]
[ 2909-79-7 ]
1-(5-tert-butyl-2-(dimethylamino)phenyl)dibenzo[b,d]furan-2-ol [ No CAS ]

Reference： [1]RSC Advances,2013,vol. 3,p. 16475 - 16485

40
[ 86-77-1 ]
[ 618-47-3 ]
[ 100-52-7 ]
N-((2-hydroxydibenzofuran-1-yl)(phenyl)methyl)-3-methylbenzamide [ No CAS ]