反应详情

A solution of nitric acid/sulfuric acid (1:2.5) was added dropwise to a stirred solution (2.7 M) of ethyl 2-thiophene carboxylate in sulfuric acid at −10° C. After stirring for an additional half an hour, the reaction mixture was poured into ice-water. The resulting precipitate was filtered, washed with water and dried to give the title compound (96%) as a mixture 1:1 of 4-nitro and 5-nitro regioisomers.

1. filtrationThe resulting precipitate was filtered
2. washwashed with water
3. customdried