1955 年 75 巻 4 号 p. 378-381
Fifteen kinds of mono-substituted benzoic acid possessing OCH3, OH, CH3, Cl, or NO2 in the ortho-, meta-, or para-position of the carboxyl were reacted respectively with phenol, in the presence of polyphosphoric acid. It was thereby found that the nuclear substitution became difficult in the order of OCH3, OH, CH3, H, Cl, and NO2, and the influence of substituents on the nuclear substitution appeared more clearly in the ortho- and para-substituted acids. Nitrobenzoic acids were most resistant to substitution.