反应详情

2.00 g (5.34 mmol) of 2,2-bis(4-nitrobenzyl)malonic acid and 2.07 g (5.35 mmol) 5-cholesten-3β-ol and 65 mg (0.53 mmol) 4-dimethylaminopyridine in 40 ml of dichloromethane were cooled to 0° C. and 1.16 g (5.62 mmol) N,N′-dicyclohexylcarbodiimde were added. The mixture was subsequently allowed to react for 2 hours at 0° C. and 19 hours at 25° C., filtered and concentrated by rotary evaporation. Chromatography of the residue on 50 g silica gel using toluene as eluant and recrystallisation form ethyl acetate yielded 3.09 g (83%) Cholest-5-en-3-yl 2-(4-nitrobenzyl)-3-(4-nitrophenyl)propanoate as a white powder.

1. addition1.16 g (5.62 mmol) N,N′-dicyclohexylcarbodiimde were added
2. customto react for 2 hours at 0° C. and 19 hours at 25° C.
3. filtrationfiltered
4. concentrationconcentrated by rotary evaporation
5. customrecrystallisation form ethyl acetate