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Kinetic data are reported for the decarboxylation of gallic acid in pyragallol, rzsorcinol and catechol. This is the first study of i t s kind i n these solvents. The reaction i s first order and non-stoichiometric. INTRQDUCTIOKThe kinetics of the decarboxylation of P-resorcylic acid have been reported by Brown et al.'). The decarboxylation of B-resorcylic acid in severa1 amines and glycols showing a bimolecular mechanism has been reported by Clarkz'. It has been shown in our earlier findings') that the decomposition of benzoic acid and B-resorcylic acid in catechol proceeds via an intermediate complex between the soIute and the solvent. It has been estabIished that benzoic acid decarboxylates at a faster rate than substituted benzoic acids. Similar results have also been reported for the decomposition of ochlorobenzoic acid and 2,4-dichIarobenzoic acid'' in resorcinol and catechol. In catechuric acid') (solute) and the solvent catechol both have two adjacent hydroxyl groups, gave the slow rates of reaction.In continuation of above study the decarboxylation of gallic acid was made in pyrogallol. The solute and the soIvent both have three adjacent hydroxyI groups.This study was also made in resorcinoI and catechol for comparison. The results suggest that the decomposition mechanism is &-similar to the mechanism observed for several carboxylic acids reported earlier'~''. However, secondary reaction among the molecules of galIic acid resulted before the effective. Chemicals main reaction could become EXPERIMENTALGallic acid (BDH) (3,4,5-trihydroxy benzoic acid), rn. p. 235*, was used without purification. It was heated in an eIectric oven at 100' for ten to twelve hours and then was stored over concentrated sulphuric acid, melted at 234.5'. PyrogalIol was Kochlight Laboratories Limited, Coinbrook Buck., England, white crystalline solid m.p. 133'. Resorcinol and catechol were white crystalIine solids, chernicaiIy pure BDH anaIytical reagent grade. Apparatus and TechniqueThe reaction was usualIy folhwed by measuring the volume of CO, evolved.The apparatus and technique are similar to those described in our previous articLe~'*~). About 20.0 grams of each solvent under study were separately taken in each experimental run. 0.3036 g of gallic acid was weighed in a sampIe tube and placed on the moveable probe inside the reactor. The set up was then placed in a constant temperature oil-bath (a0.08") and when thermal equilibrium was established,

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Kinetic data are reported for the decarboxylation of catechuric acid in four hydroxy solvents in the temperature range 150-180°0 The parameters of the absolute reaction rate equation are calculated. The reaction is first order. The observations support the view that all the decompositions proceed through an intermediate complex mechanism.The kinetics of the decomposition of benzoic acid? have been reported in our earlier investigations. It has been shown that benzoic acid decarboxylates at a faster rate in resorcinol than in catechol. Similar findings were also reported for

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