Di-tert-butyl azodicarboxylate → Di-tert-butyl 1-{3-[(4,4-difluoropiperidin-1-yl)methyl]phenyl}hydrazine-1,2-dicarboxylate

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Reaction Conditions

Reaction Steps

n-Butyllithium (1.6 M in hexanes, 4.5 mL, 7.28 mmol) was added dropwise to a stirred solution of Intermediate 12a (1.98 g, 6.82 mmol) in dry THF (15 mL) at −78° C. under nitrogen. The mixture was stirred at −78° C. for 10 min, then di-tert-butyl azodicarboxylate (1.73 g, 7.51 mmol) was added in one portion. The mixture was stirred at −78° C. for 20 min, then allowed to warm to RT over 20 min. The mixture was then partitioned between saturated ammonium chloride solution (15 mL) and ethyl acetate (3×20 mL). The combined organic extracts were washed with brine (20 mL) and dried (Na2SO4). The solvent was evaporated and the residue purified by FCC, eluting with 0-100% EtOAc in pentane, to give the title compound as a pale yellow oil (1.30 g, 43%). LCMS (Method 1): Rt 2.54 min, m/z 442 [MH+].

Provenance & Evidence