Sodium 4-toluate

Fife and Xin (35) found that, under PTC conditions, the reaction between benzoyl chloride and a mixture of 1.0 equivalent of sodium p-toluate and 1.0 equivalent of sodium isobutyrate in the presence of 0,1 equivalent of pyridine 1-oxide gave an anhydride product mixture that contained approximately twice as much benzoic p-toluic anhydride as benzoic isobutyric anhydride on a molar basis (equation 7). Therefore, the process must include an important component that selects for the more lipophilic p-toluate ion. The differential partitioning of the competing carboxylate ions at the di-chloromethane-water interface is a reasonable explanation for this observed selectivity, because product composition correlates with the Hansch (39) hydrophobicity parameters for competing carboxylate ions (40). 

The free energy of transfer of alkylphenols and alkylphenoxides to cationic micelles has been measured. For the neutral parent compound SAGq = -5.680 kcal mol and for its anion 8AGo =-6.870 kcal moP. Incremental methyl substitution changes this value by —0.300 kcal moP in both cases and it was concluded that the environment of solubilized molecule and anion are very similar. The size of micelles can be quite subtly dependent on counterion however, since sodium p-toluenesulphonate and sodium p-toluate increase the viscosity of cetyltrimethylammonium bromide solutions sharply but sodium benzenesulphonate and disodium phenylphosphate do not. The anthra-quinone sulphonate (9) is absorbed very slowly ki = 0.37s by cationic micelles, the process being accelerated by added KBr. ... 

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