反应详情

25 g. Diethyl N-(6-methoxybenzthiazol-2-yl)-aminomethylenemalonate are introduced into a solution of 36 g. sodium hydroxide, 360 ml. water and 120 ml. ethanol which has been heated to 70° C. and the reaction mixture is heated under reflux for 30 minutes. A part of the ethanol is then removed in vacuo, filtered and, after cooling, the filtrate is acidified with 2 N hydrochloric acid. 1-(2-Mercapto-4-methoxyphenyl)-5-carboxypyrimidine-2,6-dione is obtained in a yield of 14.7 g. (70% of theory). According to the melting point and the IR, UV and NMR spectra, the product is identical with the compound prepared according to Variant I.

1. temperaturethe reaction mixture is heated
2. temperatureunder reflux for 30 minutes
3. customA part of the ethanol is then removed in vacuo
4. filtrationfiltered
5. temperatureafter cooling