Pyridine → 2-[2-(tert-Butyl-dimethyl-silanyloxy)-ethyl]-(5-tert-butyl-2H-pyrazol-3-yl)-carbamic acid 2,2,2-trichloro-ethyl ester

Participants

Reaction Conditions

Reaction Steps

Dissolve 5-tert-butyl-2-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-2H-pyrazol-3-ylamine (5.5 g, 0.018 mol) in THF (100 mL) under N2 and cool to 0° C. Add pyridine (1.6 mL, 1.1 equiv.) via syringe followed by dropwise addition of 2,2,2-trichloroethyl chloroformate (2.7 mL, 1.1 equiv.). Stir the reaction at 0° C. for one hour then remove the cooling bath and allow the reaction to stir for a total of 5 hours. Dilute the reaction with ethyl acetate and water. Wash the organic layer with water then saturated aqueous saturated sodium chloride and then dry over magnesium sulfate, filter, and concentrate in vacuo to give a residue (8.7 g, 100%) that is used without further purification. MS (ES), m/z 474 (M+1).

Provenance & Evidence