Triphenylphosphine → [2-(4-Pyrazole-1-yl-phenoxy)-ethyl]-carbamic acid benzyl ester

Participants

Reaction Conditions

Reaction Steps

A round-bottomed flask was charged with 4-pyrazole-1-yl-phenol (175 mg, 1.09 mmol), and 3.6 ml of toluene, triphenylphosphine (430 mg, 1.64 mmol), and benzyl N-(2-hydroxyethyl)carbamate (320 mg, 1.64 mmol) were then added. The solution was cooled to 0° C. and 1,1′-(azodicarbonyl)-dipiperidine (414 mg, 1.64 mmol) was added. The mixture was allowed to stir for about ten minutes at about 0° C. and was then allowed to warm to room temperature. An additional 3.6 ml of toluene and 3.6 ml of tetrahydrofuran were added to the viscous solution. The reaction mixture was stirred for about forty-eight hours, and the precipitated solids were filtered off and washed with a minimum volume of 1:1 toluene/tetrahydrofuran. The filtrate was concentrated in vacuo to afford the intermediate [2-(4-pyrazole-1-yl-phenoxy)-ethyl]-carbamic acid benzyl ester as an oil which was used directly in the next step.

Provenance & Evidence