反应详情

12.4 g (0.084 mol) of dichloroacetyl chloride was added dropwise to a mixture of 12 g (0.084 mol) of piperid-4-one ethylene ketal and 12.8 g (0.084 mol) of 1,8-diazobicyclo[5.4.0]undec-7-ene in 100 ml of toluene, whilst stirring, at a rate such that the temperature of the reaction mixture did not exceed 40° C. Thereafter, the mixture was subsequently stirred at 20° C. for 2 hours. Working up was then effected by a procedure in which the reaction mixture was filtered, the filtrate was concentrated under reduced pressure and the residue was recrystallized from a mixture of toluene and petroleum ether. 10.5 g (49% of theory) of N-dichloroacetylpiperid-4-one ethylene ketal were obtained in this manner in the form of colorless crystals of melting point 102° C.

1. customdid not exceed 40° C
2. stirringThereafter, the mixture was subsequently stirred at 20° C. for 2 hours
3. filtrationwas filtered
4. concentrationthe filtrate was concentrated under reduced pressure
5. customthe residue was recrystallized from a mixture of toluene and petroleum ether