Studies on Uricosuric Diuretics. II. Substituted 7, 8-Dihydrofuro[2, 3-g]-1, 2-benzisoxazole-7-carboxylic Acids and 7, 8-Dihydrofuro[2, 3-g]benzoxazole-7-carboxylic Acids

Abstract

A series of substituted 7, 8-dihydrofuro[2, 3-g]-1, 2-benzisoxazole-7-carboxylic acids 9 and 7, 8-dihydrofuro[2, 3-g]benzoxazole-7-carboxylic acids 12 were synthesized and evaluated for uricosuric and diuretic activities in rats. Many of the benzisoxazole derivatives 9 showed uricosuric and only weak diuretic activities, whereas the benzoxazoles 12 exhibited potent diuretic activities with little affecting urate excretion. Among these compounds, 5-chloro-7, 8-dihydro-3-phenylfuro[2, 3-g]-1, 2-benzisoxazole 7-carboxylic acid (9b, AA-193) was found to be a potent uricosuric agent without diuretic activity and was selected for further development.