Pyrocatechoic acid

On the assumption that 2,3-dihydroxybenzoic acid (pyrocatechoic acid, V, = R2 = H) is formed in humans after salicylate ingestion and that it may be the antirheumatic agent, clinical studies were carried out with this compound in rheumatic fever in which it appears to be superior to sodium salicylate although of lower toxicity, but ineffective in rheumatoid arthritis i > i. Other workers found the drug to be twice as active as salicylate in rheumatic fever and less toxic in therapeutic doses . Trials with diacetyl-pyrocatechol-3-carboxylic acid (Movirene, V, R = R = COMe) in various rheumatic conditions were also favourable > . 

Michotte has suggested that biolt ical oxidation processes in mesenchymal tissues require a balance of C -hydroxysteroids and adrenergic substances, and this is disturbed in rheumatic diseases owing to the failure of the adrenergic component. It is alleged that pyrocatechoic acid (V) may replace this component, restore the physiological imbalance and, consequently, suppress the inflammatory reaction. Adams and Cobb found that neither pyrocatechoic acid nor its diacetyl derivative administered orally inhibits ultra-violet erythema in the guinea-pig. The former compound, administered subcutaneously, reduces vascular permeability in the mouse peritoneum, but the effect is less than that of salicylic acid . Other dihydroxybenzoic acids tested are not active in this system . 

Slightly bitter, cryst scales or powder, mp 134-135. One gram dissolves In 1310 ml cold water, 82 ml boiling water 15 ml cold alcohol, 2.8 m] boiling alcohol 14 ml chloroform, 90 ml ether sol in glycerol. Gives a pasty mass with phenol, chloral hydrate or pyrocatecho], strong acids or alkalies, salicylic acid, oxidizers, iodine, spirit nitrous ether. LDjq orally in rats 1.65 g/kg (Boyd). 

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