Application of Organolithium and Related Reagents in Synthesis. XV. A Concise Regiospecific Conversion of Picolinic- and Isonicotinic Acids into 2-Benzoyl- and 4-Benzoylnicotinic Acids

The synthesis of the azaphthalides (7) and (8) and their conversion into the corresponding 2- and 4-benzoyl-3-hydroxymethylpyridines (9) and (10), very useful precursors of the 2- and 4-benzoylated nicotinic acids (11) and (12), as a way of regiospecific transformation of the picolin- and isonicotinanilides (1) and (2) Into nicotinic acid derivatives, is described.