Water → 4-(Hydroxymethyl)-4-methyl-1-phenylpyrazolidin-3-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 0.163 kg (1.5 mol) phenylhydrazine, 0.630 kg (7.5 mol) sodium bicarbonate, 0.75 L toluene, 75 mL of water and 3.0 g (0.013 mol) benzyl triethylammonium chloride heated to and maintained at 60° to 70° C. while 0.466 kg (ca 2.05 mol) of 1-methyl-4-oxo-3,5-dioxa-4-thiocyclohexane carbonyl chloride are added over a period of four hours. The reaction mixture is held at 70° C. for 1 hour, and 1.5 L of water added. The reaction mixture is then heated to 80° C. and held for one additional hour at this temperature before the lower aqueous phase is decanted. Residual water is then removed by azeotropic distillation, 0.120 L of isopropanol are added at 70° C., and crystallization is induced by cooling to 0° to 5° C. The product is isolated by filtration, washed with two 0.1 L 0° to 5° C. toluene washes, and dried in a 70° C. forced-air oven overnight. Approximately 0.229 kg (1.11 mol, 74% of theoretical amount) of 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrozolidinone is isolated. The IR and NMR(H) spectra match those of this compound, M.P.: 121.8° to 123.3° C.

Provenance & Evidence