Ethyl chloroformate → HCID 69019446, compound

Participants

Reaction Conditions

Reaction Steps

Prepare a solution of 4-(2′-cyano-biphenyl-4-yl)-1-methyl-1H-pyrazole-3-carbonitrile (101 mg, 0.355 mmol, prepared in preparation 46) in 3 mL of anhydrous THF and cool to −70° C. Add n-butyl lithium (1.6M in hexanes, 0.2 mL, 0.32 mmol) dropwise, keeping the internal temperature less than −65° C. Stir the orange solution for 30 minutes at −70° C. Next, add ethyl chloroformate (0.1 mL, 1.02 mmol) and allow the reaction to warm to room temperature over one hour. Quench with 2 mL of saturated NH4Cl and dilute with 50 mL of EtOAc. Wash the organic layer with water (1×10 mL) and brine (1×10 mL) and dry over anhydrous Na2SO4. Filter, evaporate and chromatograph over silica gel (100/0-7/3 toluene/EtOAc) to give the title compound, 37 mg (29%) along with 38 mg of recovered starting material.

Provenance & Evidence