Sulfuric Acid → 4-Dimethylaminomethyl-1-p-chlorphenylpyrazolidin-3-one

Participants

Reaction Conditions

Reaction Steps

p-Chlorphenylhydrazine (14.5g) was added to a solution of sodium isopropoxide (2.3g of sodium) in dry isopropanol (200 ml). The solution was boiled under reflux and ethyl-2-dimethylaminomethylacrylate (15.7g) was added in one portion. After boiling for 20 minutes, the solution was cooled to 0° C in a stoppered flask. Sulphuric acid (125 ml, 2N) was added and the mixture was extracted with ether (3 × 250 ml). The ether extract was discarded and the aqueous solution was adjusted to a pH of 8 with sodium hydroxide solution (approx 125 ml, 2N). Extraction of the aqueous mixture with chloroform gave a pale yellow extract, which, after evaporation of the chloroform, gave a buff solid. The solid was recrystallised from carbon tetrachloride as colourless needles of 4-dimethylaminomethyl-p-chlorphenylpyrazolidin-3-one (9g, 35%, melting point 107° C).

Provenance & Evidence