1,3-Dibromopropane → 9-(5-Chloro-2-methoxy-benzenesulfonyl)-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocycloheptene-2-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Potassium carbonate (818 mg, 5.92 mmol) was added to a solution of 3-(5-chloro-2-methoxy-benzenesulfonylamino)-4-hydroxy-benzoic acid methyl ester (example 30, step 1; 1.00 g, 2.69 mmol) and 1,3-dibromopropane (597 mg, 2.96 mmol) in N,N-dimethylformamide (17 mL), and the suspension was heated at 60° C. for 5 h, then the reaction mixture was partitioned between water and ethyl acetate. The organic layer was washed with brine, dried (MgSO4), and evaporated. Chromatography (SiO2, heptane-ethyl acetate gradient) produced 9-(5-chloro-2-methoxy-benzenesulfonyl)-6,7,8,9-tetrahydro-5-oxa-9-aza-benzocycloheptene-2-carboxylic acid methyl ester (996 mg, 90%). White solid, MS (ISP)=412.1 (M+H)+.

Provenance & Evidence