EFFECT OF SUBSTITUENTS IN THE PROPYNYL FRAGMENT AND AT THE NITROGEN ATOM ON THE INTRAMOLECULAR CYCLIZATION OF (3-ARYL-2-PROPYNYL)-(4-HYDROXY-2-BUTYNYL)AMMONIUM CHLORIDES AND ALSO ON THE RECYCLIZATION OF THE PRODUCTS FORMED

Abstract

Cyclization of dialkyl(4-hydroxy-2-butynyl)[3-(α-naphthyl)-2-propynyl]ammonium chlorides using aqueous KOH solution occurs under more rigorous conditions (1:1 ratio of salt to base) than in the case of their 3-phenyl(p-chlorophenyl, alkenyl)-substituted analogs (5:1 ratio of salt to KOH). Similarly, more rigorous conditions are also needed for the cyclization of (4-hydroxy-2-butynyl)-(3-phenyl-2-propynyl)piperazinium- and dicyclohexylammonium chlorides. In addition to the cyclization products – corresponding dialkyl(7-hydroxymethyl)naphtho[1,2-f]isoindolinium or dialkyl-(4-hydroxy-methyl)benzo[f]isoindolinium chlorides, the products of recyclization of these – dialkylaminophenanthro[1,2-c]furan or dialkylaminonaphtho[1,2-c]furan are also formed. The indicated derivatives become the main products of conversion of the starting salts by a change of salt to KOH ratio, 1:2, and with an increase in the time of the reaction. The results obtained can be explained by steric effect and also the lower thermal stability of the obtained naphtho[1,2-f]isoindolinium salt system compared to the analogous benzo[f]isoindolinium systems.

Author: A. A. Khachatryan.

English translation in Chemistry of Heterocyclic Compounds, 2011, 47 (9), pp 1091-1097

http://link.springer.com/article/10.1007/s10593-011-0879-9