反应详情

温度

0 °C

15 parts by volume of an 0.5 molar solution of diazomethane in ether are added in the course of about 10 minutes to a solution, cooled to 0° C., of 1.6 parts of 3-oxo-tetrahydrothiophene-4-carboxylic acid methyl ester in 10 parts by volume of dry chloroform. The solution is stirred for 21 hours at 0° C., flushed with nitrogen to remove excess diazomethane and concentrated under reduced pressure. The residue is recrystallized from methylene chloride/petroleum ether. 1.5 parts (86% of theory) of 3-methoxy-dihydrothiophene-4-carboxylic acid methyl ester of melting point 79°-81° C. are obtained.

1. customflushed with nitrogen
2. customto remove excess diazomethane
3. concentrationconcentrated under reduced pressure
4. customThe residue is recrystallized from methylene chloride/petroleum ether