Biphenyl-2-carboxylic acid nitration

Aminobiphenyl-2- and -4-carboxylic acids 63 were prepared by nitration of biphenyl-2 -and -4-carboxylic acids 62 (yields 14 and 36%, respectively, the 2 -N02 isomer being the major compound), followed by catalytic hydrogenation (Scheme 19).[108] The isomeric 3 -aminobiphenyl-2-, -3-, and -4-carboxylic acids 64 and the 2 -aminomethyl homologues 65 were prepared by Suzuki couplingJ108 ... 

Data have been presented on the kinetics of nitration of acetanilide in mixtures of nitric and sulfuric acids.29 A review discusses the several mechanisms operative in the nitration of phenol including /> / -sclective nitrosation-oxidation and mechanisms involving phenoxy radical-nitrogen dioxide reaction yielding a 55 45 ortho para nitration ratio.30 The kinetics of mononitration of biphenyl-2-carboxylic acid have been investigated in several solvents. The maximum ortho para product ratio of 8.4 is observed in tetrachloromethane.31 Nitration products were not formed in the presence of dioxane.31,32 Quantum-chemical AMI calculations were performed and the predominant formation of the ortho-nitro product is accounted for by stabilization of the cr-complex by the carboxyl group.33... 

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