Abstract： 1-Methyl-3-phenylpiperazine was prepared by using ethyl α-Bromophenylacetate and ethylenediamine as the starting materials in the cyclization.Then with N4 protection of the Boc group,N1 methylation,N4 deprotection and reduction of amide group,1-Methyl-3-phenylpiperazine was synthesised.The total yield is 29%.On the basis of previously reported procedure,we further modified the work-up procedure in the first step of cyclization to increase the production quality and efficiency.The modification included dissolution of the crude product obtained in CH2Cl2,and subsequent reactions with a limited amount of di-tert-butyldicarbonate followed by precipitation in THF at low temperature.Our modification improved the quality of the intermediate 3-phenyl-2-piperazinone and is easily repeatable.Moreover,in the steps of N4 protection with Boc group and reduction of amide group,some changes were also made for easy application to industrial manufacturing.
2012, Vol. 36 
