Benzylamine → Ethyl 1-benzylazetidine-2-carboxylate

Reaktionsgleichung

Br[CH:2]([CH2:8][CH2:9]Br)[C:3]([O:5][CH2:6][CH3:7])=[O:4].C(N(CC)CC)C.[CH2:18]([NH2:25])[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1>O>[CH2:18]([N:25]1[CH2:9][CH2:8][CH:2]1[C:3]([O:5][CH2:6][CH3:7])=[O:4])[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Komponenten

Versuchsvorschrift

(Wasserman, H. H. et al. J Org. Chem. 1981, 46(15), 2991-2999). A mixture of (±)ethyl 2,4-dibromobutanoate (39) (15 g, 54.8 mmol), triethylamine (16.6 g, 164 mmol) and benzylamine (5.87 g, 54.8 mmol) was heated to reflux for 3 hours then concentrated under reduced pressure to give a solid suspension. Water (150 ml) was then added and the mixture extracted with ether (2×100 ml). The organic phase was dried and then concentrated under reduced pressure and the residue purified by dry flash chromatography on silica (hexanes then 1:3 ethyl acetate/hexanes) to give 40 as a pale yellow oil (6.3 g, 53%); 1H NMR (300 MHz, CDCl3) δ 7.37-7.27 (m, 5H), 4.16-4.03 (m, 2H), 3.82 (d, J=12.6 Hz, 1H), 3.73 (dd, J=8.4, 8.4 Hz, 1H), 3.61 (d, J=12.8 Hz, 1H), 3.34 (ddd, J=7.4, 7.4, 2.0 Hz, 1H), 2.95 (ddd, J=7.4, 7.4, 7.4 Hz, 1H), 2.44-2.31 (m, 1H), 2.27-2.16 (m, 1H), 1.20 (t, J=7.2 Hz, 3H); 13C NMR (75 MHz, CDCl3) δ 172.5, 137.1, 129.0, 128.7, 128.2, 127.1, 64.5, 62.4, 60.5, 50.8, 21.5, 14.0.