反应详情

A suspension of 12.2 g (0.063 mol) of 3-carbomethoxy-4-aminothiophene hydrochloride in 100 ml of methylene chloride is treated with 10 ml (0.126 mol) of chloroacetyl chloride and subsequently dropwise with 17.6 ml (0.126 mol) of triethylamine, the temperature being held below 25° C. The solution is poured into water and extracted twice with 50 ml of methylene chloride each time. The combined methylene chloride extracts are washed three times with 50 ml of water each time, dried over magnesium sulphate and evaporated. After chromatography on silica gel using methylene chloride for the elution, there is obtained crystalline 3-carbomethoxy-4-[(chloroacetyl)amino]thiophene of melting point 98°-100° C.

1. custombeing held below 25° C
2. extractionextracted twice with 50 ml of methylene chloride each time
3. washThe combined methylene chloride extracts are washed three times with 50 ml of water each time
4. dry with materialdried over magnesium sulphate
5. customevaporated
6. washfor the elution