Diethoxymethane → 7-bromo-1-(5-chloro-2-methoxy-benzenesulfonyl)-1,4-dihydro-2H-benzo[d][1,3]oxazine

Participants

Reaction Conditions

Reaction Steps

A mixture of N-(5-bromo-2-hydroxymethyl-phenyl)-5-chloro-2-methoxy-benzenesulfonamide (2.51 g, 6.17 mmol), toluene-4-sulfonic acid monohydrate (117 mg, 0.617 mmol), and formaldehyde diethyl acetal (15.5 mL) was heated under reflux at 100° C. for 16 h. After cooling, heptane was added to the suspension, which was stirred for 15 min. The precipitate was collected by filtration and dried to afford 7-bromo-1-(5-chloro-2-methoxy-benzenesulfonyl)-1,4-dihydro-2H-benzo[d][1,3]oxazine (2.25 g, 87%). Off-white solid, MS (ISP)=418.1 (M+H)+.

Provenance & Evidence