Benzothiazol-2-ylcarboxylic acids with diverse spacers: A novel class of potent, orally active aldose reductase inhibitors

The benzothiazol-2-ylcarboxylic acids, with diverse spacers between the carboxy group and the benzothiazole ring, were synthesized and evaluated for their ability to inhibit aldose reductase (AR). The phenylacetic acids 6 which have a less complex structure than that of existing AR inhibitors were found to be highly potent, orally active AR inhibitors.