Benzoquinolizine誘導体の合成 (第2報)

2-Dimethylaminoethyl-3-methyl-9,10-dimethoxy-1,2,3,4,6,7-hexahydro-11bH-benzo [a] quinolizineの合成

抄録

In order to obtain amebacidal agent, 2-dimethylaminoethyl-3-methyl-9, 10-dimethoxy-1, 2, 3, 4, 6, 7-hexahydro-11bH-benzo [a] quinolizine (IX) was prepared. Dieckmann con-densation of ethyl N-(3, 4-dimethoxyphenethyl)-N-(ethoxycarbonylpropyl) malonamate (I) afforded a β-ketoester (II), soluble in dilute sodium hydroxide solution and giving positive reaction to ferric chloride. Ketonic decomposition of (II) with 10% acetic acid followed by dehydrative condensation with ethyl cyanoacetate, and subsequent esterification, decarboxylation, and reduction afforded the carboxylic acid (VI). Cyclization and reduction of (VI) gave the quinolizine ester which was further derived to the amine (IX). The condensate (Xa) obtained from 3, 4-dimethoxyphenethylamine, 1, 1, 2-ethanetricarboxylic acid, and formaldehyde underwent automatic decarboxylation to form an aminodicarboxylic acid (XIa). Its esterification and condensation with ethoxycarbonylacetyl chloride gave the amide (XII) which was derived to the ketoester (XIV) as above, converted to the thioketal, and desulfurized and reduced to the homo acid (XVI). The use of 1, 1, 3-propanetricarboxylic acid gave an aminotricarboxylic acid (Xb) which was boiled with 60% acetic acid to effect decarboxylation and cyclization to form the lactam (XVIII) and its Arndt reaction gave the homo acid amide (XX). The compounds (XVI) and (XX) are intermediate for the preparation of the objective amine (A).