Dimethylformamide → N-[(55)-3-carbamoyl-9,10,11-trimethoxy-6,7-dihydro-5H-dibenzo[a,c]cyclohepten-5yl]acetamide

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Reaction Steps

Oxalyl chloride (0.44 g; 3.4 mmol) and DMF (50 μl) were added to a suspension of N-[(5S)-3-carboxy-9,10,11-trimethoxy-6,7-dihydro-5H-dibenzo[a,c]cyclohepten-5-yl]acetamide (1) under argon atmosphere (1.15 g; 3 mmol) in dichloromethane (10 ml). The mixture was stirred at ambient temperature for 2 hours, evaporated to dryness and redissolved in dichloromethane (20 ml). The solution was cooled at −78° C. and ammonia gas was allowed to bubble through the solution for 5 minutes. The mixture was allowed to warm up and further stirred at ambient temperature for 15 minutes. After evaporation to dryness, the residue was taken up in aqueous sodium hydrogen carbonate/ethyl acetate. The organic phase was separated, evaporated and purified by flash chromatography eluting with ethyl acetate/methanol (95/5) to give N-[(5S)-3-carbamoyl-9,10,11-trimethoxy-6,7-dihydro-5H-dibenzo[a,c]cyclohepten-5-yl]acetamide.

Provenance & Evidence