Electrophilic substitution reactions of esters of 4,5-substituted 1,3-dithiol-2-ylideneacetic and 1,3-dithiol-2-ylidenemalonic acids

The electrophilic substitution reactions (with halogens, POCl3 + DMF, diazonium salts, iodoso compounds) of both esters of 4,5-substituted 1,3-dithiol-2-ylideneacetic acids and sodium salts of monoethyl esters of the corresponding malonic acids can be used for the synthesis of 2-methylene-1,3-dithiole derivatives.