Azasetron → HCID 131716241, compound

Participants

Reaction Steps

To a solution of 5.0 g of 6-chloro-3,4-dihyro-4-methyl-3-oxo-N-(3-quinuclidinyl)-2H-1,4-benzoxazine-8-carboxamide in 100 ml of chloroform with cooling at -30° C. is added 4.02 g of 80% metachloroperbenzoic acid, and the system stirred at -20° C. to -25° C. for about 30 minutes. The resultant solution is stirred at room temperature for 20 minutes and ammonia gas is bubbled into the solution at 10°-18° C. The precipitated crystals are filtered off and the filtrate is concentrated under reduced pressure. The residue is purified with column chromatography with a mixed eluent of chloroform and methanol (10:1) and to the residue is added acetonictile. The crystals are collected by filtration and recrystallized form acetonitrile to give 6-chloro-3,4-dihydro-4-methyl-3-oxo-N-(3-quinuclidinyl)-2H-1,4-benzoxazine-8-carboxamide N-oxide hemihydrate, melting at 198°-200° C. with decomposition.

Provenance & Evidence