A Facile Synthesis of 2-Chloro-1,8-naphthyridine-3-carbaldehyde; their Transformation into Different Functionalities and Antimicrobial ActivityAuthor(s): M. Ranadheer Kumar, E. Laxminarayana, D. Ramesh, B. Sreenivasulu and M. Thirumala Chary
2-Chloro-1,8-naphthyridines-3-carbaldehyde (10-18) has been synthesized by treating various substituted N-(pyridin-2-yl) acetamides (1-9) with POCl3 in dimethyl formamide. It proceeds through Vilsmeier-Haack cyclization. The cyclization was facilitated by N-(pyridin-2-yl)acetamides bearing electron donating groups at meta position. The condensation of compound (10-18) with hydrazine hydrate and sodium acetate in methanol led to the formation of compound (19-27). The 2-chloro-1,8- naphthyridine-3-carbaldehyde was treated with sodium azide in ethanol underwent cyclization to afford tetrazolo (1,5-a)(1,8) naphthyridine-4-carbaldehyde (28-36) via unstable 2-azido compound. The reaction of compound (10-18) with sodium sulphide in DMF yielded 2-mercapto-1,8-naphthyridines-3- carbaldehyde (37-45). The synthesized new compounds have been screened for their antimicrobial activity.