Synthesis of new piperazine derivatives containing 1,3,4-oxadiazole or 1,2,4-triazole ring.

number: 
333
English
department: 
Degree: 
Imprint: 
Chemistry
Author: 
Yasmeen Asaad Mohammed Salih Al-Dhaeif
Supervisor: 
Dr. Amir T. Atto
Dr.Yousif A. Al-Fattahi
year: 
1999

Abstract:

This work describes the synthesis of new N, N-bis [(substituted-4H-l,2,4-traizole-5-yl) methyl] piperazine and N,N-bis [(substituted-1,3,4-oxadiazole-5-yl) methyl] piprazine derivatives of possible biological activity. To obtain the tagret compounds, the following reaction steps shown in scheme [I] were of a feasible strategy. The synthon N,N-bis (acetic hydrazide) piperazine [2], prepared from N,N-bis- (carbethoxy methyl) piperazine [1], was used for the preparation of three types of heterocyclic derivatives: i- Series one : Containing compounds [3a-f]. ii- Series two : Containing compounds [6a-h], [7]. iii- Series three : Containing compounds [10a-f]. N,N'-bis-[(5-(4- alkoxyphenyl)-13,4-oxadiazole-2-yl)methyl]piperazine [3a-f] were formed form the reaction of synthon [2] with p-alkoxybenzoic-acids- in presence of phosphorous oxychloride. N,N'-bis- [(3-mercapto-4-phenyl-4H-l,2,4-traizole-5-yl)methyl]piperazine [5] was synthesized from basic cyclization of the intermediate product [4] obtained from the reaction between compound [2] and phenyl isothiocyanate. Alkylation of compound [5] under SN2 reaction conditions give compounds [6a-h] and [7]. The compound N,N' -bis- [(3-mercapto-4-amino-4H-l,2,4-traizoIe-5-yl) methyl] piperazine [9], which was obtained from cyclization of xanthate salt [8] using hydrazine hydrate, was then reacted with a number of substituted benzaldehydes which gave the corresponding Schiffbases [10a-f].