反应详情

A solution of 1.5 g of 2-(4-carboxybenzamido)-4-aminobenzoic acid in 50 ml of pyridine was mixed with 3.2 g of isobutyroyl chloride and the mixture was heated at 50° to 60° C. for a period of 2 hours. The reaction mixture was further mixed with a solution of 4 g of sodium hydroxide in 20 ml of water and concentrated under vacuum. The residue was diluted with water and hydrochloric acid was used to adjust the pH of the dilution between 1 and 2. The precipitating crystal was filtered, washed with water and recrystallized from a solvent mixture of methanol and water to thereby produce 1.1 g of 2-(4-carboxybenzamido)-4-isobutyramidobenzoic acid having a melting point in the range of from 312° to 314° C. (decompose).

1. temperaturethe mixture was heated at 50° to 60° C. for a period of 2 hours
2. concentrationconcentrated under vacuum
3. additionThe residue was diluted with water and hydrochloric acid
4. filtrationThe precipitating crystal was filtered
5. washwashed with water
6. customrecrystallized from a solvent mixture of methanol and water