Synthesis of novel trans-4-(phthalimidomethyl)- and 4-(imidazol-1-ylmethyl)-3-indolyl-tetrahydroisoquinolinones as possible aromatase inhibitors

Abstract

The reaction of homophthalic anhydride with 1H-indol-3-carbaldimines was used for the preparation of trans- and cis-2-alkyl-3-indolyl-1-oxotetrahydroisoquinolin-4-carboxylic acids 3a–d. The stereochemistry of the reaction was investigated by means of 1H NMR spectroscopy. The carboxylic group of trans-3a–d was transformed stereoselectively via 4-hydroxymethyltetrahydroisoquinolin-1-ones into 4-(phthalimidomethyl)-derivatives trans-6a,b and 4-(imidazolylmethyl)-derivatives trans-8b–d. Compounds trans-6a,b and 8b–d were tested for antiaromatase activity, and the preliminary results showed that the phthalimidomethylisoquinolinone trans-6b at 50 μM concentration decreased the aromatase enzyme activity with 40%.