3,5-Dimethoxyphenol → HCID 17748129, compound

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Reaction Steps

3,5-Dimethoxyphenol is reacted with N,N-dimethylthiocarbamoyl chloride in the presence of sodium hydride in DMF to give 1-dimethylaminothiocarbonyloxy-3,5-dimethoxybenzene of m.p. 77°-78°. This product is rearranged, by heating for half an hour at 270°, to give 1-dimethylaminocarbonylmercapto-3,5-dimethoxybenzene, which, in the crude state, by leaving to stand for 3 days with ethanolic KOH, is saponified to give 3,5-dimethoxythiophenol of b.p. 103°-109°/0.25 mm. Reaction with glutaconic acid dimethyl ester gives 3-(3,5-dimethoxyphenylmercapto)-glutaric acid dimethyl ester, which is converted, at 80° by means of polyphosphoric acid, into 5,7-dimethoxy-thiochroman-4-one-2-acetic acid methyl ester of m.p. 98°-99°. The corresponding free acid (m.p. 180°-182°) is converted, via the chloride and the amide (m.p. 199°-202°), into the corresponding nitrile (m.p. 123°-124°), which is split, by means of BBr3, into 5-hydroxy-7-methoxy-thiochroman-4-one-2-acetonitrile (m.p. 97°-98°). Analogously to Example 1, there are obtained therefrom 5-hydroxy-7-methoxy-thiochroman-4-one-2-acetaldehyde (m.p. 112°-115°), 2-phenyl-4-[2-(5-hydroxy-7-methoxy-thiochroman-4-on-2-yl)-ethylidene]-2-thiazolin-5-one (m.p. 97°-99°), 4-thiobenzamido-1,4,4a,5,5a,6,11,12-octahydro-3,10,12-trihydroxy-8-methoxy-1,11-dioxo-6-thianaphthacene-2-carboxamide (mixture of stereo-isomers), 4-de-dimethylamino-4-thiobenzamido-8-methoxy-12a-dehydroxy-6-thiatetracycline (m.p. 212°-215°) and, finally, by hydroxylation

Provenance & Evidence