1-Chloroethyl chloroformate → 3-(4-Fluorophenoxy)azetidine hydrochloride

Participants

Reaction Steps

To a stirred solution of 1-(diphenylmethyl)-3-(4-fluorophenoxy)azetidine (Intermediate 123, 3.2 g, 9.6 mmol) in DCE (20 ml) was added dropwise 1-chloroethylchloroformate (1.6 ml, 1.5 eq). The mixture was stirred 10 min then heated to reflux for 6 h. More 1-chloroethylchloroformate was added (1.6 ml) and heating was continued for 3 h. The mixture was cooled to room temperature and concentrated under vacuum. The residue was dissolved in MeOH (20 mL) and left to stand overnight. The mixture was heated under reflux and stirred for 1 h, then cooled to room temperature and concentrated under vacuum. The residue was crystallised under diethyl ether; the solid was broken up with a spatula, filtered off—washing with diethyl ether—and dried under vacuum to give the title compound as a cream solid (1.78 g, 91%). Method B HPLC-MS: MH+ requires m/z=168 Found: m/z=168, Rt=0.69 min (92%). 1H NMR (250 MHZ, DMSO-d6) δ ppm 9.50 (2H, br s), 7.15 (2H, t), 6.89 (2H, dd), 5.03 (1H, m), 4.39 (2H, m), and 3.93 (2H, m).

Provenance & Evidence