Reaction #969865

Reaction equation

Lysine

diallyl glutamate

triphosgene

Et3N

→

ninhydrin

Solvents

CH2Cl2

CH2Cl2

CH2Cl2

CH2Cl2

Conditions

Workup

1. 1
   workup.STIRRINGthe reaction was stirred at room temperature for 12 h
2. 2
   Washwashed twice with H2O
3. 3
   Dryingdried over MgSO4 (anh.)
4. 4
   Otherpurified by column chromatography (Hexane:AcOEt 3:1→2:1→AcOEt)

Procedure

To a stirred solution of diallyl glutamate (3.96 g, 15 mmol) and triphosgene (1.47 g, 4.95 mmol) in CH2Cl2 (143 mL) at −78° C. was added Et3N (6.4 mL, 46 mmol) in CH2Cl2 (28 mL). The reaction mixture was allowed to warm to room temperature and stirred for 1.5 h. The Lysine derivative (2.6 g, 9.09 mmol) in a solution of CH2Cl2 (36 mL) was then added at −78° C. and the reaction was stirred at room temperature for 12 h. The solution was diluted with CH2Cl2, washed twice with H2O, dried over MgSO4 (anh.) and purified by column chromatography (Hexane:AcOEt 3:1→2:1→AcOEt) to give 4 g (82%) (TLC in CH2Cl2:MeOH 20:1 Rf=0.3, revealed with ninhydrin). 1H-NMR (CDCl3, 300 MHz) δ 5.97-5.84 (m, 3H, 3-CH2CHCH2), 5.50 (bt, 2H, 2NHurea), 5.36-5.20 (m, 6H, 3-CH2CHCH2), 4.81 (bs, 1H, NHBoc), 4.68-4.40 (m, 8H, 3-CH2CHCH2, CH(Lys), CH(glu)), 3.09-3.05 (m, 2H, CH2NHBoc), 2.52-2.39 (m, 2H, CH2(glu.)), 2.25-2.14 and 2.02-1.92 (2m, 2H, CH2(glu.)), 1.87-1.64 (m, 4H, 2CH2(Lys)), 1.51-1.35 (m, 2H, CH2(Lys)), 1.44 (s, 9H, Boc).

Source