イソヒノリン誘導体の合成研究 (第17報)

パパベリン類似化合物の研究 その2 1-(2´,4´-Dihydroxyphenyl)-及び1-(3´,4´-Dihydroxyphenyl)-3-methyl-6,7-methyienedioxyisoquinolineの合成 (附記β-Resorcylic Acidのbenzyl化反応)

抄録

As an example of water-soluble papaverine-like compounds possessing two hydroxyls in the phenyl ring in 1-position, two out of six theoretically possible derivatives were prepared as 1-(2′, 4′-dihydroxyphenyl)- and 1-(3′, 4′-dihydroxyphenyl)-3-methyl-6, 7-methylenedioxyisoquinoline. Benzylation was attempted in order to protect the hydroxyl in the β-resorcylic acid, but the objective 2, 4-dibenzyloxybenzoic acid could not be obtained and in its stead, a mixture of several compounds were obtained. Acetylation was then carried out, followed in the ordinary manner to chloride, amide and the isoquinoline cyclization which was attended by deacetylation by which the first compound was obtained. For the preparation of the latter, dibenzylprotocatechualdehyde was oxidized with hydrogen peroxide, followed through carboxylic acid, chloride and amide to 1-(3′, 4′-dibenzyloxyphenyl) derivative which was catalytically reduced to a phenolic base but this compound was very unstable and became resinous.