Dimethylamine → Boc-Lys(Z)-Tyr(tBu)-Lys(Z)

Participants

Reaction Steps

To a solution of Fmoc-Tyr(tBu)-Lys(Z)-OMe (7.72 g, 10.49 mmol) in THF (105 mL), was added dimethyl amine (52.5 mL, 2 M, 104.9 mmol). This reaction was allowed to reach room temperature and stirred for 1.5 h. At this time, the reaction mixture was concentrated in vacuo. To the yellowish solid, was added DCM (225 mL) and DMF (45 mL). To this solution, was added Boc-Lys(Z)—OH (4.19 g, 11.01 mmol), then HOBt (1.488 g, 11.01 mmol), then EDC.HCl (2.112 g, 11.01 mmol). This solution was allowed to stir for 8 h at which time the organic solution was washed with 1 N HCl (3×100 mL), then saturated NaHCO3 (3×100 mL), and finally H2O (3×100 mL). The organic layer became jelly like and MeOH was added to break the gel. The organic layer was dried over MgSO4 and concentrated in vacuo to yield a white solid. Column chromatography (0-1% MeOH, CHCl3) afforded the product (5.51 g, 65% yield).

Provenance & Evidence