反应详情

A mixture of 3-t-butoxycarbonylaminothiophene-2-carboxylic acid (10.0 g, 41.1 mmol), diphenylphosphoryl azide (14.14 g, 51.37 mmol) and triethylamine (5.85 ml, 42.2 mmol) in t-butyl alcohol (1000 ml) was stirred under reflux for 10 hours. The mixture was evaporated and the residue was dissolved in methylene chloride (300 ml). The solution was washed successively with 5% aqueous citric acid, water, saturated aqueous NAHCO3, followed by evaporation to give 5.9 g of a substance which was purified by recrystallization from heptane-methylene chloride to afford di-t-butyl thiophene-2,3-dicarbamate. M.p. 168°-170° C. Litt. m.p.: 165°-167° C. (J. Chem. Res. (S), 296, 1985).

1. temperatureunder reflux for 10 hours
2. customThe mixture was evaporated
3. dissolutionthe residue was dissolved in methylene chloride (300 ml)
4. washThe solution was washed successively with 5% aqueous citric acid, water, saturated aqueous NAHCO3
5. customfollowed by evaporation
6. customto give 5.9 g of a substance which
7. customwas purified by recrystallization from heptane-methylene chloride