29547-04-4

100-46-9

18085-37-5

Methyl 2,4-dibromobutyrate (10.01 g, 38.49 mmol, 1.0 eq.) was dissolved in methanol (15 mL) and slowly added dropwise to a stirred solution of triethylamine (11.68 g, 16.01 mL, 115.5 mmol, 3.0 eq.) in methanol (40 mL) at 0 °C. After dropwise addition, stirring was continued for 15 minutes. Subsequently, benzylamine (4.33 g, 4.41 mL, 40.4 mmol, 1.05 eq.) was added dropwise to a methanol (25 mL) solution and stirring was continued for 30 minutes after completion of the dropwise addition. The reaction mixture was then slowly warmed to room temperature and stirred overnight. Upon completion of the reaction, the mixture was concentrated under vacuum, diluted with diethyl ether (100 mL) and filtered to remove insoluble solids. The organic phase was washed with water (200 mL) and the aqueous phase was then back-extracted with ether (3 x 50 mL). The organic phases were combined, dried with anhydrous sodium sulfate, filtered and concentrated in vacuum. The crude product was purified by column chromatography (25% ethyl acetate/hexane) to afford methyl 1-benzylazetidine-2-carboxylate as an orange oil (2.02 g, 26% yield). Thin layer chromatography (TLC) Rf value was 0.35 (ethyl acetate:hexane = 1:3). IR spectrum (neat, cm?1): 2953, 2837, 1737, 1442, 1201, 1172. 1H NMR (300 MHz, CDCl3) δ: 7.35-7.17 (m, 5H, ArH), 3.84-3.70 (m, 2H CH2Ph), 3.62 (s, 3H, OCH3), 3.58 (d, 1H, J=12.5 Hz, COCH), 3.35-3.27 (m, 1H, NCH2a), 2.98-2.88 (m, 1H, NCH2b), 2.36 (dt, 1H, J= 8.7, 17.6 Hz, CHCH2a), 2.25-2.13 (m, 1H, CHCH2b).13C NMR (75 MHz, CDCl3) δ: 173.10, 137.08, 129.17, 128.36, 127.32, 64.40, 62.45, 51.83, 50.85, 21.72. 50.85, 21.72. high-resolution mass spectrometry (HRMS, ESI) m/z: 206.1198 ([M+H]+, calculated value 206.1175).