反应详情

A mixture of 26 g of dimethyl thiodiacetate and 32 g of butyl 2-(fur-3-yl)-2-oxo-acetate is added dropwise, over 30 minutes at 64°-68° C., to a mixture of 100 ml of methyl alcohol and 39.9 g of potassium tert.-butanolate. The reaction mixture is kept at this temperature for a further 3 hours, and then poured into a mixture of 179 g of ice and 58 g of concentrated hydrochloric acid. The resultant crystals are separated off, washed with ice water until free of chloride, and dried at 60 C./0.1 mbar. Yield: 27.9 g. The product is recrystallized from 250 ml of methyl alcohol, and 22 g of 2,5-bis-(methoxycarbonyl)-3-fur-3-yl-4-hydroxythiophene having a melting point of 102° C. are obtained.

1. customThe resultant crystals are separated off
2. washwashed with ice water until free of chloride
3. customdried at 60 C
4. customThe product is recrystallized from 250 ml of methyl alcohol, and 22 g of 2,5-bis-(methoxycarbonyl)-3-fur-3-yl-4-hydroxythiophene having a melting point of 102° C.
5. customare obtained