反应详情

温度

0 °C

5-Bromopyridine-2-carboxylic acid (20 g, 100 mmol, Frontier Scientific catalog# B1704) was stirred in methylene chloride (30 mL) and cooled to 0° C. 2.0 M Oxalyl chloride in methylene chloride (100 mL) was added slowly followed by DMF (0.8 mL). Vigorous degassing occurred. The mixture was stirred at 0° C. for 30 min and at rt overnight. The mixture was evaporated and redissolved in methylene chloride (130 mL). Dimethylamine hydrochloride (9.8 g, 120 mmol) was added and the mixture was cooled to 0° C. Triethylamine (56.1 mL, 400 mmol) was added slowly (over 5 minutes) which caused significant exotherm and precipitation of a brown/orange solid. The mixture was stirred at rt for 2 h. The mixture was diluted with methylene chloride and washed with saturated sodium bicarbonate, brine, dried over sodium sulfate, filtered and evaporated. Purification on silica gel using ethyl acetate in hexanes (0-60%) gave the desired compound, (22.0 g, 100%). LCMS calculated for C8H10BrN2O (M+H)+: m/z=229.0, 231.0. found: 228.9, 230.9.

1. customVigorous degassing
2. customThe mixture was evaporated
3. dissolutionredissolved in methylene chloride (130 mL)
4. temperaturethe mixture was cooled to 0° C
5. customexotherm and precipitation of a brown/orange solid
6. stirringThe mixture was stirred at rt for 2 h
7. additionThe mixture was diluted with methylene chloride
8. washwashed with saturated sodium bicarbonate, brine
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. customevaporated
12. customPurification on silica gel