反应详情

7.5 g (0.023 mol) of N-benzyloxycarbonyl-L-alanyl-L-alanine ethylamide were stirred for 1 hour in 50 ml of 4-N hydrobromic acid in acetic acid. To the solution were added 300 ml of dry ether and, after stirring for a few minutes, the oil was allowed to settle and the ether decanted from the oil and discarded. The oil was then dissolved in methanol, the desired L-alanyl-L-alanine ethylamide hydrobromide crystallising out on the addition of ethyl acetate. The yield was 6.0 g (83%) and the melting point was 229°-231° C.; [α]D20 =-28.0° (c=1% in water).

1. customthe ether decanted from the oil
2. dissolutionThe oil was then dissolved in methanol
3. additionthe desired L-alanyl-L-alanine ethylamide hydrobromide crystallising out on the addition of ethyl acetate
4. custom[α]D20 =-28.0° (c=1% in water)