p-Toluenesulfonic acid monohydrate → HCID 18364140, compound

Participants

Reaction Steps

A stirred suspension of 4-(4′-chloro-biphenyl-4-yl)-4-hydroxyimino-butyric acid (2.126 g, 0.00700 mol) and (4-methylphenyl)sulfonic acid monohydrate (0.067 g, 0.00035 mol) in toluene (22 mL) was heated under nitrogen at reflux over a Dean-Stark trap for 7 hours, and allowed to cool. The volatiles were rotary evaporated. The residue was dissolved/suspended in dichloromethane and chromatographed on silica gel (221 g, 230-400 mesh), eluting with dichloromethane (20×200 mL) to give 0.63 g of 3-(4′-chloro-biphenyl-4-yl)-4,5-dihydro-6-oxo-6H-1,2-oxazine as a light purple solid; mp 190-192° C.

Provenance & Evidence