反应详情

Nα -(Benzyl-oxycarbonyl)-L-lysine (5.0g m, 17.84 mmol) was dissolved in 268 ml of tert-butyl acetate containing 2.80 ml of perchloric acid (69-72% aqueous solution). The solution was stirred for 2 days at room temperature and then was extracted with water (3×200 ml). The combined aqueous layers were adjusted to pH 10 with 50% sodium hydroxide. The aqueous solution was then extracted with ethyl acetate (3×200 ml) and the organic layers dried over MgSO4. After filtration to remove MgSO4, the solvent was removed by evaporation at reduced pressure to provide Nα -(benzyloxycarbonyl)-L-lysine tert-butyl ester as a clear oil (2.16 gm, 36%). 1H NMR (CDCl3) 1.35 (s,9H), 1.40-2.0 (m,6H), 2.60 (t,2H), 4.10 (m,1H), 4.98 (s,2H), 5.29 (bs,1H), 7.35 (s,5H).

1. extractionwas extracted with water (3×200 ml)
2. extractionThe aqueous solution was then extracted with ethyl acetate (3×200 ml)
3. dry with materialthe organic layers dried over MgSO4
4. filtrationAfter filtration
5. customto remove MgSO4
6. customthe solvent was removed by evaporation at reduced pressure