2,4-ヂオキシ-6,7-メチレンヂオキシーキノリン-3-アルデヒドの合成

抄録

6-Nitropiperonylic acid was prepared from 6-nitro-piperonal according to Mameli's method and converted by PCl₅ into the chloride, which was condensed with diethyl malonate in benzene solution at 30-40° by the Bischoff's method to diethyl 3, 4-methylenedioxy-6-nitrobenzoyl molonate (I), oily liquid. By the reduction of the crude (I) with Sn and conc. HCl in hot alcoholic solution, 2, 4-dihydroxy-6-methylenedioxyquinoline was formed as white crystals, m.p. over 320° (nitroso compound: dark reddish purple crystals, m.p. 241-242° (decomp.)). 2, 4-Dihydroxy-6, 7-methylenedioxyquionoline-3-aldehyde (III) was obtained by adding the excess of CHCl₃ slowly to (II) in 15% NaOH on a water bath. Yield, 53.7% of the theory. Almost colorless leaflets (from alcohol), m.p. 316-318° (decomp.). Phenylhydrozone of (III): yellow needles, m.p. 226°.