Reactions of some αβ-unsaturated pyrazolyl compounds with bromine and with grignard reagents

An Efficient Synthesis of Isomeric 1‐(1‐Alkyl‐1H‐pyrazolyl) Ethanones

“…Acylpyrazoles are the important intermediates in the synthesis of pyrazole derivatives. The described methods of their synthesis are: interaction of organomethallic (Li or Mg) derivatives of pyrazole with nitriles , acyl chlorides , or anhydrides of carbonic acids , decarboxylation of pyrazol ketoacids , by oxidation of alcohols or propenyl substituted pyrazoles , by condensation of polycarbonyl compounds with hydrazines , by multistep synthesis started from substituted alkynes , by catalytic carbonilation of pyrazoles in the presence of Ru 3 (CO) 12 and by other methods. 4‐Acylpyrazoles were also obtained by direct acylation of pyrazoles by acyl chlorides under drastic conditions (150–200°C).…”