反应详情

To a suspension of (3R,5S)-7-chloro-5-(2-methoxyphenyl)-1-neopentyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-acetic acid (12 g) in methanol (200 ml) was added 1N aqueous sodium hydroxide (27.7 ml). After the acid was dissolved completely, the mixture was concentrated in vacuo. To the residue was added ethyl acetate (200 ml) and the mixture was concentrated in vacuo. The deposited crystals were collected to give sodium (3R,5S)-7-chloro-5-(2-methoxyphenyl)-1-neopentyl-2-oxo-1,2,3,5-tetrahydro-4,1-benzoxazepine-3-acetate (11.8 g) as colorless crystals (mp>300° C.).

1. dissolutionAfter the acid was dissolved completely
2. concentrationthe mixture was concentrated in vacuo
3. additionTo the residue was added ethyl acetate (200 ml)
4. concentrationthe mixture was concentrated in vacuo
5. customThe deposited crystals were collected