1,4-Dithiino[2,3-c; 6,5-c']diisothiazole and related compounds
AssigneeE. I. Du Pont de Nemours and Company
InventorSusan Anne Vladuchick
Life of this patent
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Abstract
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.degree. C in the presence of a basic catalyst. The diisothiazole can be converted to derivatives with various utilities, e.g., as fluorescent brighteners.
Claims10
A diisothiazole of the formula ##STR17## wherein both R's are the same and are -H, -CN, -COCl, -CO.sub.2 R.sup.1, -CONR.sup.2 R.sup.3 or -CO.sub.2 -(alkyl).sub.4 N.sup.+,
- R.sup.1 is -H, alkyl of 1-5 carbon atoms, phenyl, -K or benzyl;
- R.sup.2 and R.sup.3 are each selected from the group consisting of -H, alkyl of 1-5 carbon atoms, phenyl and phenyl substituted with alkyl, alkoxy, nitro, halo, or dialkylamino, in which the alkyl is from 1-5 carbon atoms.
The compound of claim 1, 3,7-dicyano-1,4-dithiino[2,3-c;6,5-c']diisothiazole.
The compound of claim 1, 1,4-dithiino[2,3-c;
- 6,5-c']diisothiazole.
The compound of claim 1, 1,4-dithiino[2,3-c;
- 6,5-c']diisothiazole-3,7-dicarboxylic acid.
Dependencies are inferred from the claim text.