Synthesis and Analgesic and Anti-Inflammatory Activities of (3,3-Dipropyl-6,7-Dimethoxy-3,4-Dihydroisoquinolin-1(2H)-Ylidene)-Acetamide Hydrochlorides

Abstract

Cyclocondensation of 4-(3,4-dimethoxybenzyl)heptan-4-ol with N-substituted cyanoacetamide was used to synthesize (3,3-dipropyl-6,7-dimethoxy-3,4-dihydroisoquinolin-2(2H)-ylidene)acetamides. The hydrochlorides of the resulting enaminoamides exist in the imino form. All hydrochlorides displayed analgesic effects in the hotplate test at the level of sodium metamizole, and the most active were the amide with the N-substituted 2-(3,4-dimethyoxyphenyl)ethyl radical, which had greater levels of analgesic activity than metamizole and nimesulide. Many of the resulting amides displayed anti-inflammatory effects in a carragheenan model which were comparable in magnitude to those of sodium metamizole.