反应详情

A mixture of 29 g of 2-methyl-5-thiazolecarboxaldehyde, 30 ml of pyridine, 29 g of malonic acid and 30 drops of piperidine was heated at 100°-100°C for 5 hours and was then returned to room temperature and poured into 500 ml of water. The pH of the solution was adjusted to 3 by addition of N sulfuric acid and the mixture was vacuum filtered. The recovered precipitate was dried to obtain 27.8 g of 3-(2-methyl-5-thiazolyl)-2-propenoic acid which was crystallized from 800 ml of ethanol containing 10% ethanol to obtain 23.8 of the said product melting at 204°C.

1. temperaturewas heated at 100°-100°C for 5 hours
2. customwas then returned to room temperature
3. filtrationfiltered
4. customThe recovered precipitate was dried