反应详情

6.7 g of 85% potassium hydroxide in 1130 ml of ethanol are added at room temperature to 22.1 g of 2-methoxymethyl-4-methylthiazole-5-carboxylic acid ethyl ester and the reaction mixture is then heated under reflux for 18 hours. After cooling, the ethanol is evaporated off and the residue is dissolved in 200 ml of water. After stirring with active carbon, the mixture is filtered over Hyflo and the filtrate is acidified with concentrated hydrochloric acid with vigorous stirring. The resulting yellowish crystals are filtered off, washed with water and dried. After recrystallisation from tetrahydrofuran/petroleum ether (30°-45° C.) (=10:1) the yellowish crystals melt at 168°-169.5° C.

1. temperaturethe reaction mixture is then heated
2. temperatureunder reflux for 18 hours
3. temperatureAfter cooling
4. customthe ethanol is evaporated off
5. dissolutionthe residue is dissolved in 200 ml of water
6. filtrationthe mixture is filtered over Hyflo
7. filtrationThe resulting yellowish crystals are filtered off
8. washwashed with water
9. customdried
10. customAfter recrystallisation from tetrahydrofuran/petroleum ether (30°-45° C.) (=10:1) the yellowish crystals
11. custommelt at 168°-169.5° C.