反应详情

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.

1. customevaporated to dryness
2. dissolutionredissolved in dichloromethane (20 ml)
3. temperatureThe solution was cooled at −78° C.
4. customto bubble through the solution for 5 minutes
5. temperatureto warm up
6. stirringfurther stirred at ambient temperature for 15 minutes
7. customAfter evaporation to dryness
8. customThe organic phase was separated
9. customevaporated
10. custompurified by flash chromatography
11. washeluting with ethyl acetate/methanol (95/5)