反应详情

N-(Benzoyl)-D,L-norleucine (40 g., 170 mmole) is taken into 300 ml. of tetrahydrofuran with stirring in an ice bath. To this is added dropwise dicyclohexylcarbodiimide (38.52 g., 187 mmole) in tetrahydrofuran (195 ml.). After 15 minutes the bath is removed and the reaction is allowed to run overnight. The dicyclohexylurea is filtered off and the filtrate is concentrated to dryness. The crude product (31.7 g.) is purified on silica gel in hexane:ether (2:1) to give 2-phenyl-4-butyl-5(4H)-oxazolone. This product crystallizes neat when refrigerated.

1. customAfter 15 minutes the bath is removed
2. filtrationThe dicyclohexylurea is filtered off
3. concentrationthe filtrate is concentrated to dryness
4. customThe crude product (31.7 g.) is purified on silica gel in hexane:ether (2:1)