反应详情

Trifluoroacetic acid (40 ml) was added slowly to a stirred solution of 4-(2-tert-butoxycarbonyl-ethyl)-3-methyl-benzoic acid methyl ester from Example E30.2 (4.9 g, 17.6 mmol) in dichloromethane (80 ml) at room temperature. The mixture was stirred for 2 h then concentrated in vacuo and azeotroped with dichloromethane. The residue was recrystallised in EtOAc to yield the title compound (2.77 g, 71%).

1. concentrationthen concentrated in vacuo
2. customazeotroped with dichloromethane
3. customThe residue was recrystallised in EtOAc