Key intermediates for the synthesis of organic semiconductors: a direct dithiocarbamate route to unsubstituted 1,3-dithiol-2-one derivatives
Abstract
Acid-catalyzed cyclization of formylmethyl piperidine-1-carbodithioate dimethyl or diethyl acetals (2a,b) at elevated temperatures is a key step in a convenient route to 1,3-dithiole-2-thione (1b) and 1,3-dithiole-2-selone (1c)via the unsaturated dithiolium salt (4); attempted cyclizations of (2a) and (2b) at lower temperatures led to alkoxy-substituted dithiolium salts (3a) and (3b).