Straightforward microwave-assisted synthesis of 1-carboxymethyl-5- trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazoles under solvent-free conditions

Article abstract of DOI:10.1002/jhet.309

(Chemical Equation Presented) An efficient microwave-assisted synthesis of 1-carboxymethyl-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazoles from the cyclocondensation reaction between enones [CF₃C(O)C(R²) = C(R¹)(OR), where R² = H, Me; R¹ = H, Me, Et, Pr, i-Pr, t-Bu, i-Bu, Ph, 4-NO₂-Ph, 4-Cl-Ph, 4-Br-Ph, 4-F-Ph and R = Me, Et] and methyl hydrazinocarboxylate under solvent-free conditions is reported. This process is an efficient alternative to the traditional thermal heating and furnishes the heterocyclic compounds in good to excellent yields in a short reaction time. To show the versatility of 1-carboxymethyl-5- trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazoles, dehydration reactions of these compounds are also demonstrated.