Acetic Anhydride → N,3-bis-(4-chlorophenyl)-4-dimethylcarbamoyl-4-methyl-N-acetyl-4,5-dihydro-1H-pyrazole-1-carboxamide

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Reaction Steps

In a 50 ml round bottomed flask was placed 0.45 g of 60% sodium hydride (0.011 mole). The sodium hydride was washed twice with hexane and suspended in 15 ml of tetrahydrofuran. A solution of 2.0 g (0.005 mole) of N,3-bis-(4-chlorophenyl)-4-dimethylcarbamoyl-4-methyl-4,5-dihydro-1H-pyrazole-1-carboxamide in 5 ml of tetrahydrofuran was added slowly. When hydrogen evolution ceased, 1 ml of acetic anhydride was added and the mixture was stirred for 5 minutes. The reaction was partitioned between ethyl ether and brine, dried, concentrated, and chromatographed yielding 1.6 g of N,3-bis-(4-chlorophenyl)-4-dimethylcarbamoyl-4-methyl-N-acetyl-4,5-dihydro-1H-pyrazole-1-carboxamide, an oil. NMR and IR data were consistent with the structure.

Provenance & Evidence