Sodium Iodide → tert-Butyl 4-cyano-4-(3,4-dichlorophenyl)piperidine-1-carboxylate

Participants

Reaction Steps

To a stirred solution of 2-(3,4-dichlorophenyl)acetonitrile (3.50 g, 18.8 mmol, CASRN 3218-49-3) and 15-crown-5 (0.414 g, 1.88 mmol) in DMF (75 mL) at 0° C. under nitrogen was added NaH (1.88 g, 47.0 mmol, 60% mineral oil dispersion) in 2 portions. The reaction mixture was warmed to RT and stirred 35 min then re-cooled to 0° C. NaI (2.82 g, 18.8 mmol) was added followed by a solution of freshly prepared tert-butyl bis-(2-chloroethyl)carbamate (4.56 g, 18.8 mmol) in DMF (10 mL) via syringe. The reaction mixture was warmed to RT and stirred overnight. The reaction mixture was then poured into ice cold sat'd. NH4Cl solution (250 mL) with stirring and the mixture was extracted with EtOAc (2×250 mL). The combined extracts were dried (MgSO4), filtered and concentrated. The crude product was loaded onto a SiO2 column (Biotage 40L) and eluted with hexanes/EtOAc (6/1) to afford 4.54 g (68%) of tert-butyl 4-cyano-4-(3,4-dichlorophenyl)piperidine-1-carboxylate (356) as an off white solid.

Provenance & Evidence