Synthesis of alkoxyphthalimide derivatized oxoimidazolidinyl oxazolo/thiazolo dihydropyrimidine and oxoimidazolidinyl tetrahydropyrimidine via common Schiff base intermediate and evaluation of their antibacterial activity

摘要

Synthesis of N-(2-(4-substituted phenyl)-3-(2-(1,3-dioxoisoindolin-2-yloxy)ethyl)-5-oxoimidazolidin-1-yl)-3-(2-(1,3dioxoisoindolin-2-yloxy)ethyl)-6-methyl-2-oxo/thioxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxamides and N-(2-(4-substituted phenyl)-3-(2-(1,3-dioxo-2,3-dihydro-1H-inden-2-yloxy)ethyl)-5-oxoimidazolidin-l-yl)-7-methyl-3-oxo-5-phenyl-3,5-dihydro-2H-oxazolo/thiazolo[3,2-a]pyrimidine-6-carboxamides are described in the present investigation by multistep reactions via common intermediate. 6-methyl-2-oxo/thioxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate have been prepared by three component Beginelli reaction between benzaldeyde, urea/thiourea and ethyl acetoacetate which is further converted to carbohydrazide derivatives by treating it with hydrazine hydrate. Condensation of with various araldehydes produces the key intermediate N-(4-substituted benzylidene)-6-methyl-2-oxo/thioxo-4-phenyl-1,2,3,4-tetrahydropyrimidine-5-carbohydrazides. Reactions towards route (A) have been carried out by treating it with glycine to afford its imidazolidinone derivatives. Condensation of two replaceable hydrogens with bromoethoxyphthalimide gives the final products. Route (B) have been propagated by reaction of with chloroacetic acid which yields substituted benzylidene)-7-methyl-3-oxo/thioxo-5-phenyl-3,5-dihydro-2H-oxazolo/thiozolo [3,2-a]pyrimidine-6-carbohydrazides. Cyclisation of this with glycine produces imidazolidenone ring derivatives N-(2-(4-substituted phenyl)-5-oxoimidazolidin-1-yl)-7-methyl-3-oxo/thioxo-5-phenyl-3,5-dihydro-2H-oxazolo[3,2-a]pyrimidine-6-carboxamides. Acidic hydrogen of this ring is replaced by ethoxyphthalimide group to give targeted compounds. Structures of synthesized compounds have been confirmed on the basis of chemical tests and spectral studies. Eight compounds have been screened for antibacterial evaluation.