Acetic Acid → HCID 58763951, compound

Participants

Reaction Steps

To a solution of 4-amino-1-(2-chlorophenyl)-5-(4-chlorophenyl)-1H-pyrazole-3-carboxylic acid ethyl ester (I-4a, 1.88 g, 5 mmol) and (2-oxo-ethyl)-carbamic acid tert-butyl ester (1590 mg, 10 mmol) in 1,2-dichloroethane (60 ml) at room temperature was added glacial acetic acid (858 microliters, 15 mmol) and NaBH(OAc)3 (2540 mg, 12 mmol). The reaction mixture was stirred for 23 hours, then additional (2-oxo-ethyl)-carbamic acid tert-butyl ester (500 mg, 3.14 mmol) and NaBH(OAc)3 (1000 mg, 4.7 mmol) were added. The reaction mixture was stirred for an additional 24 hours, quenched with 1 N NaOH, and diluted with CH2Cl2. The organic layer was separated and the aqueous layer extracted with CH2Cl2. The combined organic phases were washed with 0.5 M aqueous citric acid, 1 N NaOH, and saturated aqueous NaCl, dried, and concentrated in vacuo. The crude residue was purified on a Biotage 40+M column using CH2Cl2/MeOH (100:1) to give the desired product I-4b (900 mg): +ES MS (M+1) 519.5.

Provenance & Evidence