Sodium Hydroxide → 5-(2-chloro-4-fluorophenyl)-1,3-dimethyl-1H-pyrazol-4-amine

Participants

Reaction Steps

A mixture of N-[5-(2-chloro-4-fluorophenyl)-1,3-dimethyl-1H-pyrazol-4-yl]carbamate (i.e. the product of Step E) (7.07 g, 23.8 mmol) and aqueous sodium hydroxide (1 N, 70 mL) in methanol (70 mL) was heated at reflux for 20 h. The reaction mixture was concentrated under reduced pressure, diluted with water and extracted with ethyl acetate (2×30 mL). The combined organic layers were extracted with hydrochloric acid (1 N, 2×30 mL), and the pH of the combined aqueous extracts was adjusted to 10 with the addition of sodium hydroxide (1 N). The aqueous mixture was extracted with ethyl acetate (2×40 mL). The combined organic extracts were washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered and concentrated under reduced pressure to provide the title compound as a viscous yellow oil (4.36 g).

Provenance & Evidence