反应详情

37 ml of a 4 N solution of hydrochloric acid in dioxane were added to the carbamate from Example 61A (5.30 g, 7.33 mmol), and the mixture was then stirred at RT for 1 h. Another 37 ml of a 4 N hydrochloric acid solution in dioxane were added, and the mixture was stirred at 60° C. for 3 h. The reaction solution was concentrated under reduced pressure and the residue was taken up in 1 N aqueous hydrogen chloride solution. After washing of the aqueous phase with diethyl ether, the aqueous phase was concentrated under reduced pressure. The crude product obtained in this manner was used further without further purification. Yield: 3.20 g (92% of theory)

1. stirringthe mixture was stirred at 60° C. for 3 h
2. concentrationThe reaction solution was concentrated under reduced pressure
3. washAfter washing of the aqueous phase with diethyl ether
4. concentrationthe aqueous phase was concentrated under reduced pressure