the chloroheterocycle of procedure ii was accomplished with n formylpiperazine n t butyloxycarbonylpiperazine piperazine 1 methylpiperazine or several other appropriate amines a solution 1 mmole 3 ml of chloroheterocycle from procedure ii in benzene was stirred while 4 equivalents of piperazine 1 carboxyaldehyde was added the mixture was stirred and heated under reflux for about six to eight hours after the mixture had cooled to room temperature it was filtered and the benzene phase was concentrated to dryness the residue was purified by chromatography on silica gel using 2 4 methanol in chloroform for elution concentration of product containing fractions to dryness under reduced pressure yields product that usually will crystallize on standing deformylation of the product is carried out according to procedure iv alternatively the displacement reaction was run in isoamyl alcohol at 100 u00b0 c for 12 18 hours when the reaction was complete the mixture was concentrated to dryness under reduced pressure and the residue was partitioned between the components of a chloroform water system at ph 10 11 the product was purified by chromatography on silica gel using 2 methanol in chloroform for elution a solution 1 mmole 4 ml of chloroheterocycle from procedure ii in isoamyl alcohol was added dropwise in the course of about one hour to a solution 1 mmole 4 ml of n t butyloxycarbonylpiperazine in isoamyl alcohol at 100 u00b0 120 u00b0 c the reaction mixture is monitored for disappearance of chloroheterocycle by thin layer chromatography.