Synthesis and nucleophilic displacement reactions of biologically active 2,4-dichlorobenzofuro [3,2-d] pyrimidines

Abstract

1,2,3,4-Tetrahydro-2,4-dioxobenzofuro [3,2-d] pyrimidine was converted into 2,4-dichlorobenzofuro [3,2-d] pyrimidine (4) by treatment with phosphorus pentachloride. The dichloro compound 4 was subjected to nucleophilic displacement reactions with nucleophiles such as, alkoxides, amines, azides and hydrazine. The hydrazine compounds were converted into tetracyclic benzofuro [3,2-d] pyrimidine fused with triazole. Similar tetracyclic heterocyclc containing tetrazole ring system was prepared by the diazotization of compound 11 and also by the reaction of dichloro compound (4) with one equivalent of sodium azide. The reaction of 4 with two equivalents of sodium azide yielded pentacyclic heterocyclic with two fused tetrazole ring system (14). All the compounds thus prepared were screened for antibacterial activity against Gram positive and Gram negative organisms.