反应详情

Methyl 3-t-butoxycarbonylaminothiophene-2-carboxylate (15.0 g, 58.3 mmol) was warmed in a mixture of 1 N sodium hydroxide (116.6 ml) and tetrahydrofuran (60 ml) at 50° C. for 16 hours. The mixture was evaporated to a volume of approximately 60 ml, and acidified (pH=2) with hydrochloric acid under cooling in an ice bath. The precipitate was filtered off, washed with water, and dried to afford 13.8 g (97%) of 3-t-butoxycarbonylaminothiophene-2-carboxylic acid. M.p. 168°-169° C. Litt. m.p. 168-169° C. (i. Chem. Res. (S) , 296, 1985). 1H-NMR (DMSO-D6, δ) : 1.49 (s, 9H), 7.76 (d, 1H), 7.85 (d, 1H), 9.45 (s, 1H), 13.45 (s, 1H) .

1. customThe mixture was evaporated to a volume of approximately 60 ml
2. temperatureunder cooling in an ice bath
3. filtrationThe precipitate was filtered off
4. washwashed with water
5. customdried