反应详情

The (R)-(−)-1-tert-butylcarbonylmethyl-2-oxo-3-amino-5-cyclohexyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepine thus obtained was dissolved in 550 ml of ethyl acetate. To the resulting solution was added 16.31 g of oxalic acid dihydrate to dissolve the latter in the former. Then, 367 ml of n-hexane was added and the mixture was stirred overnight. Crystals so precipitated were collected by filtration with suction, washed with a mixed solvent of ethyl acetate and n-hexane (1:1), and then dried, whereby 55 g of (R)-(−)-1-tert-butylcarbonylmethyl-2-oxo-3-amino-5-cyclohexyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepine oxalate monohydrate was obtained.

1. dissolutionto dissolve the latter in the former
2. customCrystals so precipitated
3. filtrationwere collected by filtration with suction
4. washwashed with a mixed solvent of ethyl acetate and n-hexane (1:1)
5. customdried