反应详情

Trifluoroacetic acid (80 ml) was added to N-(tert-butoxycarbonyl)-3-(4-thiazolyl)-L-alanine (42, 21.79 g, 80 mmol) which was synthesized in accordance with the method described in the literature (Synth. Commun., 20, 3507 (1990)) and the resulting mixture was stirred for 2 h under ice-cooling, Subsequently, to the mixture was added p-toluenesulfonic acid hydrate (15.22 g, 80 mmol) and the resulting mixture was stirred for 30 min. at room temperature. The reaction mixture was concentrated in vacuo. To the residue was added water and methanol, and excess trifluoroacetic acid was removed by concentrating in vacuo. To the residue was added diethyl ether and the precipitation which appeared was filtered off to give 29.8 g (quantitative) of the compound (43).

1. customwas synthesized in accordance with the method
2. temperaturecooling
3. stirringthe resulting mixture was stirred for 30 min. at room temperature
4. concentrationThe reaction mixture was concentrated in vacuo
5. additionTo the residue was added water and methanol, and excess trifluoroacetic acid
6. customwas removed
7. concentrationby concentrating in vacuo
8. additionTo the residue was added diethyl ether
9. customthe precipitation which
10. filtrationappeared was filtered off