反応 #2467959
ord-b8422c6e9b4748fc896b3462859076a5
反応方程式
反応条件
実験手順
Diazotization of methyl 4-aminothiophene-3-carboxylate with sodium nitrite followed by treatment with dimethylamine provides methyl 4-[(dimethylamino)diazenyl]thiophene-3-carboxylate. Treatment of the ester with ammonia gave the required 4-[dimethylamino)diazenyl]thiophene-3-carboxamide (compd. No. 13). The methyl 4-aminothiophene-3-carboxylate is produced using known procedures in the prior art (33, 34, 35). Thus addition of methyl acrylate to methyl thioglycolate provided methyl 3-[(methoxycarbonyl)methylthio]propanoate in quantitative yield, which on cyclization in presence of sodium methoxide gave methyl 4-oxo-2,3,5-trihydrothiophene-3-carboxylate. Treatment of methyl 4-oxo-2,3,5-trihydrothiophene-3-carboxylate with hydroxylamine followed by basification with ammonia gave methyl 4-aminothiophene-3-carboxylate.