Synthesis, structural analysis and pharmacological effects of N2-substituted 3,4-dihydrobenzo[h]quinolin-2-amines

The introduction outlines possibilities for the design of potentially pharmacologically interesting new modifications of phenylethylamine (1) and reviews already known and nearly prepared derivatives of 1 with bridged side chains. The N2-substituted 3,4-dihydrobenzo[h]quinolin-2-amines 11a-e represent bridged beta-azanaphthylethenamines or naphthyl-formamidines. Their synthesis started from 3-chloro-N-(1-naphthyl)propionamide (14) and led via dihydrobenzoquinolinone 15, thione 19 and methylthiobenzoquinoline hydroiodide 20. HI as intermediates first to the hydroiodides of 11a-e. Treatment of 11c, d. HI with sodium hydroxide yielded the free amines 11c, d. Structure, tautomerism, (Z, E)-isomerism and conformation of the prepared benzoquinolines were studied and elucidated by one and two dimensional NMR. A synopsis of the manyfold pharmacological effects, which were found in the course of the testing of 11a-e. HI, completes the paper.