Hydrochloric Acid → 5-(3,4-Dimethoxyphenyl)-2-{1-[(3-hydroxyphenyl)carbonyl]piperidin-4-yl}-4,4-dimethyl-2,4-dihydro-3H-pyrazol-3-one

Participants

Reaction Steps

10 g 3-({4-[3-(3,4-dimethoxyphenyl)-4,4-dimethyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl]piperidin-1-yl}carbonyl)phenyl acetate (compound described in example 12) are dissolved in a mixture of 200 ml THF, 100 ml acetone and 200 ml of methanol. To this mixture 200 ml of 2 M methanolic sodium hydroxide solution are added, and the reaction mixture is stirred at RT for 1 h until the reaction is completed according to TLC analysis. The reaction mixture is acidified with concentrated aqueous hydrochloric acid, and the solvents are largely removed under reduced pressure, while the crude product is precipitating. The solids are collected and washed with water to yield the title compound.

Provenance & Evidence