反应详情

A mixture of 23.7 g of 2-amino-4,5-dimethoxybenzoic acid, 19.5 g of 1,1'-carbonyldiimidazole and 600 ml of tetrahydrofuran Was stirred for 2 hours at room temperature and then saturated with anhydrous ammonia with ice bath cooling. After 24 hours, the reaction mixture was diluted with 50 ml of water, heated at reflux for 2 hours and then concentrated under reduced pressure to about 50 ml. This liquid was mixed with 100 ml of 0.1N sodium hydroxide and then extracted with three 200 ml portions of dichloromethane. The extracts were combined, dried and evaporated. The residue was crystallized from acetonitrile, giving 5.5 g of 2-amino-4,5-dimethoxybenzamide as light grey crystals, mp 135°-138° C.

1. waitAfter 24 hours
2. temperatureheated
3. temperatureat reflux for 2 hours
4. concentrationconcentrated under reduced pressure to about 50 ml
5. additionThis liquid was mixed with 100 ml of 0.1N sodium hydroxide
6. extractionextracted with three 200 ml portions of dichloromethane
7. customdried
8. customevaporated
9. customThe residue was crystallized from acetonitrile