Synthesis and Characterization of Substituted 4-Methoxy-1H-quinolin-2-ones

An efficient method for the synthesis of various substituted 4-methoxy-1H-quinolin-2-ones from various substituted aniline with malonic acid, phosphorous oxychloride, sodium methoxide and glacial acetic acid under different conditions is described. The title compounds were synthesized from three steps; the first step involved the synthesis of substituted 2, 4-dichloro quinoline from aniline (substituted), with malonic acid and phosphorous-oxychloride. In the second step, the substituted 2, 4 dichloro compounds was heated with freshly prepared methanolic sodium methoxide solution to give 2, 4-dimethoxy quinoline compounds, it was then refluxed with glacial acetic acid and hydrochloric acid to give the titled compounds in the final step. The purity of the synthesized compounds was confirmed by their C, H and N analysis and the structure was analyzed on the basics of Mass, FT-IR and 1H NMR.