Abstract Formylation of ten accessible phenylhydrazones and semicarbazones derived from alkyl, benzyl, and cycloalkyl methyl ketones with the complex of POCl 3 with dimethylformamide was studied. Depending on the electronic and steric structure of the substrates, the reaction yields 1-phenyl-or 1-unsubstituted 3, 4-dialkyl-, 3-alkyl-4-aryl-, or 3- alkyl-4-formylpyrazoles. These compounds can be readily oxidized into the corresponding ...
