反应详情

3-chloro-4-(cyanomethyl)-N-(3-hydroxypyridin-2-yl)benzamide (550 mg, 1.9 mmol) was refluxed in POCl3 (15 mL) for 2.5 h. Excess POCl3 was removed by distillation and the mixture was cooled to rt. The crude mixture was diluted with H2O. The aqueous layer was made basic (pH 14) with 1N NaOH and extracted with CH2Cl2 (3×20 mL). The residue was adsorbed onto silica gel and purified by automated flash chromatography using an EtOAc/hexane gradient to afford (2-chloro-4-[1,3]oxazolo[4,5-b]pyridin-2-ylphenyl)acetonitrile as a colorless solid: 1H NMR (CDCl3, 300 MHz) δ 8.65–8.63 (d, 1H), 8.41 (s, 1H), 8.30–8.27 (d, 1H), 7.93–7.90 (d, 2H), 7.77–7.74 (d, 2H), 7.38–7.34 (m, 2H) 3.95 (s, 2H). MS (ESI) 270 (M+H)+.

1. customExcess POCl3 was removed by distillation
2. additionThe crude mixture was diluted with H2O
3. extractionextracted with CH2Cl2 (3×20 mL)
4. custompurified by automated flash chromatography