Dimethylformamide → 2-Chloro-4-(chloromethyl)-3-methylpyridine

Participants

Reaction Steps

(2-Chloro-3-methyl-pyridin-4-yl)-methanol (12-4, impure, 0.200 g) was dissolved in 5 mL anhydrous DCM under N2. Anhydrous DMF (0.098 mL, 1.3 mmol) and POCl3 (0.118 mL, 1.27 mmol) were added and the reaction was stirred at RT for 17 h. The reaction was quenched with sat NaHCO3 (aq) and extracted 3× with DCM. The organic phases were dried over Na2SO4, filtered and concentrated to provide 2-chloro-4-chloromethyl-3-methyl-pyridine still contaminated with a major by-product. 2-Chloro-4-chloromethyl-3-methyl-pyridine (impure, 0.215 g) was stirred in 3 mL DMSO. 1-Acetylpiperazine (0.626 g, 4.88 mmol was added and the reaction was stirred at RT overnight. The solution was purified by directly loading onto a preparative reverse phase column to afford an oil which slowly crystallizes. TFA salt: 1H NMR (CD3OD) δ 8.30 (d, 1H, J=5.0 Hz), 7.53 (d, 1H, J=5.0 Hz), 4.48 (s, 2H), 3.84 (bs, 4H), 3.39-3.30 (m, 4H), 2.14 (s, 3H).

Provenance & Evidence