4-Chlorophenyl Isocyanate → N,3-bis-(4-chlorophenyl)-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide

Participants

Reaction Steps

In a 500 ml round bottomed flask was placed 82 g (0.42 mole) of 3-(4-chlorophenyl)-4-methyl-4,5-dihydro-1H-pyrazole dissolved in 300 ml of methylene chloride and the solution was brought to boiling. A solution of 64.5 g of 4-chlorophenyl isocyanate (0.42 mole) in 100 ml of methylene chloride was added at a rate to maintain reflux. After stirring for an additional 30 minutes the solvent was removed in vacuo and the resulting oil was crystallized from ethyl ether yielding 140 g of N,3-bis-(4-chlorophenyl)-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide. mp 139°-140° C. NMR data was consistent with the structure.

Provenance & Evidence