General procedure for the synthesis of methyl 2-(azetidin-3-yl)acetate hydrochloride from tert-butyl 3-(2-methoxy-2-oxoethyl)azetidine-1-carboxylate: to tert-butyl 3-(2-methoxy-2-oxoethyl)azetidine-1-carboxylate (200 mg, 872.33 μmol, 1.00 eq.) in methanol (2 mL) at 0 °C A 4 M solution of methanolic hydrochloric acid (2 mL, 9.17 eq.) was slowly added to the solution. The reaction mixture was stirred at 25 °C for 2 hours. Upon completion of the reaction, the solvent was removed by concentration under reduced pressure to afford the crude product methyl 2-(azetidin-3-yl)acetate hydrochloride (112 mg, 867.14 μmol). The structure of the product was confirmed by 1H NMR (400 MHz, CD3OD) with characteristic peaks located at δ 4.16 (t, J=9.9 Hz, 2H), 3.95-3.87 (m, 2H), 3.73-3.65 (m, 3H), 3.28-3.19 (m, 1H), 2.78-2.69 (m, 2H).
