Analgesic and antipyretic activities of 4-hydroxyisophthalic acid.

Abstract

4-HYDROXYisoPHTHALIC acid is a by-product of the manufacture of salicylic acid by the Kolbe–Schmitt reaction and has been found to be a major constituent of the ‘brown dust’ residues from the sublimation process for the purification of salicylic acid1. Analysis of a typical sample of ‘brown dust’ showed it to contain 10 per cent of salicylic, 82 per cent of 4-hydroxyisophthalic and 3 per cent of 2-hydroxyisophthalic acids, together with some inorganic material. From this source there is thus potentially available a considerable quantity of 4-hydroxyisophthalic acid, the chemistry of which is being investigated as part of a research programme on the Kolbe–Schmitt reaction at the Chemical Research Laboratory2. From a consideration of its structural similarity to salicylic acid, it was suggested at the Chemical Research Laboratory that 4-hydroxyisophthalic acid might also possess similar pharmacological properties. Accordingly, in February 1954, a pharmacological investigation was initiated at Ware and, since the findings were favourable, biochemical studies were also undertaken.