6-methoxy-1-methylene-3,4-dihydro-1H-isoquinoline-2-carboxylic acid benzyl ester → 7-Methoxy-2-oxo-1,2,4,5-tetrahydrobenzo[d]azepine-3-carboxylic acid benzyl ester

Participants

Reaction Steps

To a solution of 6-methoxy-1-methylene-3,4-dihydro-1H-isoquinoline-2-carboxylic acid benzyl ester (0.66 g) in 20 mL of glacial acetic acid was added lead tetraacetate (1 g). The reaction was stirred overnight, then quenched by the addition of 2 mL of glycerol. The volatile material was evaporated and the resulting residue was partitioned between 50 mL of saturated sodium chloride and 50 mL of dichloromethane. The aqueous phase was re-extracted with 50 mL more dichloromethane and the combined extracts were dried over sodium sulfate. The volatile material was evaporated and chromatography (20% ethyl acetate in hexanes) yielded 0.20 g of 7-methoxy-2-oxo-1,2,4,5-tetrahydrobenzo[d]azepine-3-carboxylic acid benzyl ester.

Provenance & Evidence