1,4-Dithiino 2,3-c; 6,5-c'!diisothiazole and related compounds

摘要

The compound 3,7-dicyano-1,4-dithiino 2,3-c; 6,5- c'!diisothiazole is prepared by reacting either tetracyano-1,4-dithiin or 4,5-dicyano-1,3- dithiolen-2-one with sulfur in 1,2-dimethoxyethane at a temperature of 50. degree.-280° C in the presence of a basic catalyst. The diisothiazole can be converted to derivatives with various utilities, e.g. , as fluorescent brighteners.