Quinoline 5.8- dimethoxy-2,4-dimethyl

Nitropyrido[l,2-A]quinolin-6-ium-l 1-olate (6%) was isolated from a reaction mixture obtained by photoirradiation of crystalline photochromic 2-(2, 4 -dinitrobenzyl)pyridine for 10 days <2004JP0865>. Reaction of l-(3-chloropropyl)-6,7-dimethoxy-3-methylbenzo[c]pyrylium perchlorate with hydrazines and hydroxylamine in refluxing MeOH afforded 9,10-dimethoxy-6-methyl-, -4,6-dimethyl-l,2,3,4-tetrahydropyridazino[6,l-tf]isoquinoli-nium, and 9,10-dimethoxy-6-methyl-l,2,3,4-tetrahydro[l,2]oxazino[3,2- ]isoquinolinium, perchlorates, respectively <2004CHE1131>. 

Emetine has been synthesized from 6,7-dimethoxy-l-methyl-3,4-dihydroiso-quinoline by condensation with dimethyl 3-methoxyallylidenemalonate in meth-... 

At the same time an important paper (67) appeared in which essentially the same conclusions with regard to the structure of bebeerine were arrived at by a different route. Faltis, Kadiera, and Doblhammer (67) treated the inactive a, a -dimethylbebeerine methine, obtained by a one-stage Hofmann degradation of bebeerine dimethyl ether, with ozone and obtained a mixture of two dimethylamino dialdehydes. These were not isolated but were converted to the chloromethylate derivatives, oxidized with potassium permanganate to the acids, and boiled with dilute alkah to decompose the quaternary bases. Besides trimethylamine, a mixture of two vinyl carboxylic acids were obtained. One of these proved to be 4, 6-dicarboxy-2,3-dimethoxy-5-vinyldiphenyl ether (LIX). The other vinyl carboxylic acid, which was readily separated from LIX by virtue of its low solubility, was first decarboxylated by heating with quinoline and naturkupfer C and then oxidized with potassium permanganate in acetone. This yielded 4-carboxy-2,2 -dimethoxydiphenyl ether (LXIII), the structure of which was proved by direct comparison with the synthetic compound prepared by the Ullmann condensation of o-bromoanisole and vanillic acid. 

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