tert-Butanol → 1-Methyl-5-phenoxy-1H-pyrazol-4-ylamine

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 1-Methyl-5-phenoxy-1H-pyrazole-4-carboxylic acid (16.0 g; 73.3 mmol), t-BuOH (51.2 g; 691 mmol) in 1,4-dioxane under argon are added DIPEA (37.4 g; 290 mmol) and diphenylphosphoryl azide (41.6 g; 151 mmol). After 10 minutes at ambient temperature it is heated up to 110° C. and stirred for 3 hours. The solvent is evaporated and the crude material purified by column chromatography. This compound is dissolved in DCM and treated with 4 M HCl in 1,4-dioxane. It is stirred for 2 days at ambient temperature. The solvent is evaporated and the residue dissolved in water and washed with EtOAc. The aqueous layer is basified with aqueous NaHCO3 solution and is extracted with EtOAc. The organic layer is dried and concentrated to dryness.

Provenance & Evidence