Thionyl Chloride → 5-Allyloxy-pyrrolidine-2-carboxylic acid methyl ester hydrochloride
Reaction equation
[CH3:1][O:2][C:3]([CH:5]1[CH2:9][CH2:8][CH:7]([O:10][CH2:11][CH:12]=[CH2:13])[N:6]1C(OC(C)(C)C)=O)=[O:4].S(Cl)([Cl:23])=O>CO>[ClH:23].[CH3:1][O:2][C:3]([CH:5]1[CH2:9][CH2:8][CH:7]([O:10][CH2:11][CH:12]=[CH2:13])[NH:6]1)=[O:4]Participants
4
Procedure
To a solution of 5-allyloxy-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester, 4, (7.28 g, 27 mmol) in MeOH is added thionyl chloride (4 mL, 54 mmol). The solution is stirred overnight and the solvent removed in vacuo to afford 4.25 g (95% yield) of the desired product as a dark yellow crystal. 1H-NMR (300 MHz, CDCl3): δ 11.47 (s, 1H), 8.15 (s, 1H), 5.81 (m, 1H), 5.23 (m, 2H), 4.55 (s, 1H), 3.85 (s, 3H), 2.88 (m, 1H), 2.59–2.42 (m, 2H), 2.24 (m, 1H), 1.81 (m, 1H). 13C-NMR (75.5 MHz, CDCl3): δ 170.0, 132.7, 132.3, 120.2, 119.6, 60.6, 60.2, 59.4, 58.9, 53.9, 36.6, 29.5, 29.2, 28.3. ESI MS 170.13 (M+H).