Abstract: Side chain oxidation of 2, 5-bis-@-styryl and 2, 5-bis-2-furylthiazolo [5, 4-d] thiazole with permanganate furnished 2, 5-thiazolothiazoledicarboxylic acid in good yields. The dicarboxylic acid has served as starting material for a variety of thiazolothiazole derivatives that are inaccessible by direct routes. Stepwise decarboxylation led to 2- thiazolothiazolecarboxylic acid and to the parent heterocycle. Thiazolothiazole is ...
![2,5-distyrylthiazolo[5,4-d]thiazole Structure](https://image.chemsrc.com/caspic/106/27396-04-9.png)
![diethyl [1,3]thiazolo[5,4-d][1,3]thiazole-2,5-dicarboxylate Structure](https://image.chemsrc.com/caspic/129/27484-49-7.png)
![Thiazolo[5,4-d]thiazole-2,5-dicarboxylicacid Structure](https://image.chemsrc.com/caspic/299/27492-59-7.png)