3-Pyridinecarboxaldehyde, 2-amino- → HCID 67388842, compound

HRID 908485Notes

Reaction equation

[NH2:1][C:2]1[C:7]([CH:8]=[O:9])=[CH:6][CH:5]=[CH:4][N:3]=1.[NH2:10][C:11]1[C:12](O)=[C:13]([CH:18]=[CH:19][CH:20]=1)[C:14]([O:16][CH3:17])=[O:15]>CO.ClCCl>[NH2:1][C:2]1[C:7]([CH:8]2[NH:10][C:11]3[CH:20]=[CH:19][CH:18]=[C:13]([C:14]([O:16][CH3:17])=[O:15])[C:12]=3[O:9]2)=[CH:6][CH:5]=[CH:4][N:3]=1

Participants

Conditions

Temperature: 50 °C

Procedure

A 2-aminopyridine-3-carbaldehyde (650 mg) was added to a stirred solution of methyl 3-amino-2-hydroxy-benzoate (890 mg) in methanol (10 ml) and dichloromethane (5 ml). The resulting solution was stirred at 50° C. for 10 hours. The crude product was purified by flash chromatography on silica gel eluting with 1 to 2% methanol in dichloromethane. The solvent was evaporated to dryness to afford methyl 2-(2-amino-3-pyridyl)-2,3-dihydro-1,3-benzoxazole-7-carboxylate (400 mg) as a pale yellow solid. Manganese(IV) oxide (4629 mg) was added to a solution of this yellow solid (400 mg) in dichloromethane (5 ml) and tetrahydrofuran (10 ml), the mixture was stirred at 25° C. for 15 hours. The mixture was filtered and the filtrate was adsorbed on silica gel and purified by flash chromatography on silica gel eluting with 30 to 50% ethyl acetate in petroleum ether. The solvent was evaporated to dryness to afford methyl 2-(2-amino-3-pyridyl)-1,3-benzoxazole-7-carboxylate (345 mg) as a pale yellow solid. NMR Spectrum: (CDCl3) 4.06 (s, 3H), 6.79 (dd, 1H), 6.89 (bs, 2H), 7.43 (dd, 1H), 7.92 (dd, 1H), 8.00 (dd, 1H), 8.26 (dd, 1H), 8.44 (dd, 1H); Mass spectrum: M+H+ 270;

Workup

customThe crude product was purified by flash chromatography on silica gel eluting with 1 to 2% methanol in dichloromethane
customThe solvent was evaporated to dryness

Sources & evidence

ORD record: ord-2671d36a104349079858758a67bc905c
Source dataset: uspto-grants-2011_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08017611B2

Reaction notes

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