Dimethylformamide → 3,5-Dichloro-4-pyridinecarboxaldehyde

Participants

Reaction Conditions

Reaction Steps

Form a solution of lithium diisopropylamide by the adding n-butyl lithium (37.5 mL, 0.06 mol, 1.6 M in hexanes) to diisopropylamine (8.40 mL, 0.06 mol) in tetrahydrofuran (200 mL) at −10 to−20° C. under a nitrogen atmosphere. Stir for 30 min., and cool to −60° C. Add 3,5-dichloropyridine hydrochloride (7.40 g, 0.05 mol) in small portions and stir for 1.5 hours at this temperature. Add N,N-dimethylformamide (7.75 mL, 0.10 mol) dropwise via syringe and stir for 1 hour near −60° C. Add water (200 mL) when the mixture is warmed near 0° C. and extract with ethyl acetate. Dry over sodium sulfate and concentrate in vacuo. Elute over silica gel with methanol/dichloromethane to give the desired aldehyde (2.94 g, 33%) as a light solid. MS(EI): Exact Mass Calc'd for: C6H3NOCl2 176.9562 m/z. Found: 176.9582 m/z.

Provenance & Evidence