Dimethylformamide → Boc-Ala-Ala-NH-(CH2)3-Br

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a cold (−15° C.) solution of Boc-Ala-Ala-OH (908 mg, 3.5 mmol) and NMM (570 μl, 5.23 mmols) in THF (15 ml) was added ECF (341 μl, 3.6 mmols) under N2 atmosphere and vigorously stirred. After 2 min of stirring, a solution of 1-amino-3-propylbromide hydrobromide (976 mg, 4.90 mmols) in a mixture of THF:DMF (4 mL: 3 mL) was added to the mixture followed by NMM (951 μl, 8.73 mmols) and stirred. After 10 min the mixture was warmed to 25° C. and stirred for further 8 h. THF was removed under reduced pressure and the resulting viscous solution was diluted with water (10 mL) and thoroughly extracted with ethyl acetate. The combined organic extracts were washed with 5 ml saturated citric acid, 5 ml saturated NaHCO3 and dried over by Na2SO4 and concentrated to give a residue, which was purified by silica gel flash column chromatograph (EtOAc:Hexane—3:7) to give the desired product as a solid (m.p. 146° C.) in good yields (1.022 g, 78%). (TLC:EtOAc—Rf—0.39).

Herkunft & Nachweise