反应详情

A solution of 3 g of ethyl 2-(4-carboxybenzamido)-4-aminobenzoate in 30 ml of pyridine was mixed with 3 g of propionyl chloride, and the mixture was held at 40° to 50° C. for a period of 3 hours. Subsequently, 20 ml of water was gradually added to the mixture which was held at the temperature for a period of one hour. After further addition of 100 ml of water, hydrochloric acid was used to control the pH of the reaction mixture between 1 and 2, and the precipitating crystal was filtered, washed with water, and recrystallized from a solvent mixture of ethanol and water to thereby produce 2.2 g of ethyl 2-(4-carboxybenzamido)-4-propionamidobenzoate having a melting point in the range of from 246° to 248° C.

1. waitwas held at the temperature for a period of one hour
2. filtrationthe precipitating crystal was filtered
3. washwashed with water
4. customrecrystallized from a solvent mixture of ethanol and water