反应详情

14.0 g (50 mmol) of 5-amino-4-(2-chlorobenzoyl)-thiophene-2-carboxylic acid [the synthesis is carried out analogously to Hromatka et al., Monatsh. Chem. 104, 973 (1973)] are suspended in 250 ml of anhydrous dichloromethane, 8 ml of thionyl chloride are added dropwise, and the mixture is stirred at room temperature for 2.5 hours. It is then evaporated in vacuo, the residue is taken up in dichloromethane, and the solution is added dropwise to a mixture of 7 g (50 mmol) of glycine ethyl ester hydrochloride and 16 ml of triethylamine in 100 ml of anhydrous dichloromethane. After 1 our at room temperature the mixture is extracted with water. The residue from the concentrated organic phase is worked up by chromatography on silica gel. 8.1 g (44% of theory) of the title compound of melting point 216°-218° C. are obtained.

1. customIt is then evaporated in vacuo
2. extractionAfter 1 our at room temperature the mixture is extracted with water