Benzaldehyde → HCID 13578301, compound

Participants

Reaction Steps

Nα-Benzyloxycarbonyl-O-benzyl(L) lysine paratoluene sulphonate (5.5 g) in water (100 cm3) and ethyl acetate (200 cm3) was treated with sodium carbonate to pH 10. The ethyl acetate phase was washed with saturated brine (3×200 cm3), dried (anhydrous magnesium sulphate) and evaporated to an oil, yield=4.4 g of free amino compound. This was dissolved in chloroform (100 cm3), benzyl alcohol (10 cm3) and treated with 1.2 equivalents of benzaldehyde, stirred for 2 hours then treated with excess sodium borohydride. The solids were filtered off and the filtrate washed with saturated brine (5×150 cm3), dried and evaporated to an oil. This oil was dissolved in ether (300 cm3) and treated with para-toluene sulphonic acid in ether until in slight excess. An oil formed which crystallised at -10° overnight. The crystals were filtered off and washed with dry ether, then treated with sodium carbonate whilst stirring vigorously in ethyl acetate and water to pH 10. The organic phase was washed with saturated brine (4×100 cm3), dried and evaporated to afford the title compound as an oil, yield=3.1 g (57%) ν(film) 3330 (br), 1720, 750, 740, 700 cm-1, δ(CDCl3) 1.1-1.9 (6H, bm, NCH2 (CH2)3CH), 1.20 (1H, s, exchanges+D2O; CH2NH), 2.52 (2H, bt, J 6 Hz, NCH2 (CH2)3), 3.69 (2H, s, NCH2C6H5), 4.20-4.52 (1H, bm, ##STR11## 5.05 and 5.11 (2×2H, 2×s, 2×CO2CH2C6H5), 5.20-5.50 (1H, m, exchanges+D2O; NHCO2), 7.25 (5H, s) and 7.28 (10H, s); 3×CH2C6H5. C28H32N2O4 requires 460.2359; 460.2367 found m/e 460 (M+), 369 (M+--91), 308, 262, 261, 174, 160, 155, 120, 106, 92, 91 (100% I), 65. The title compound was obtained as a white crystalline solid from ethyl acetate-cyclohexane, ν (NUJOL) 3320 (broad), 1725, 1687, 1535, 750, 725, 695 cm-1. [α]D20 c=1% in chloroform=+0.61°.

Provenance & Evidence