The reactivity of 4′-substituted-biphenyl-2-carboxylic acids with diazodiphenylmethane in various alcohols

The reactivities of a series of 4'-substituted-biphenyl-2-carboxylic acids have been investigated in their reaction with diazodiphenylmethane, in ten alcohols at 30 degrees C, by the known spectrophotometeric method. The rate data for these acids have been correlated with a simple Hammett equation by means of the sigma(p) constants. The transmission of polar effects through the double bond, in terms of the transmission coefficient rho/rho(0), has been discussed. For the reaction of a given acid in ten various alcohols, the log k and rho values have been correlated through multiple regression on appropriate solvent parameters. The results obtained for 4'-substituted-biphenyl-2-carboxylic acids have been compared with the results for 2-(4-phenyl-substituted)-cyclohex-1-enylcarboxylic acids and (Z)-4-substituted cinnamic acids under the same experimental conditions.