Réaction #1596967

Équation de réaction

NaBH(OAc)3

(S)-4-(3-((S)-6-amino-1-tert-butoxy-1-oxohexan-2-yl)ureido)-5-tert-butoxy-5-oxopentanoic acid

AcOH

tert-butyl 2-(2-formyl-1H-imidazol-1-yl)acetate

→

(S)-4-(3-((S)-6-(bis((1-(2-tert-butoxy-2-oxoethyl)-1H-imidazol-2-yl)methyl)amino)-1-tert-butoxy-1-oxohexan-2-yl)ureido)-5-tert-butoxy-5-oxopentanoic acid

Rendement 52.0%

Solvants

DCE

Conditions de réaction

Traitement

1. 1
   AutreThe reaction mixture was quenched with water
2. 2
   Concentrationconcentrated under reduced pressure
3. 3
   Autreto afford a residue which
4. 4
   Autrewas purified by on a Biotage

Mode opératoire

A solution of (S)-4-(3-((S)-6-amino-1-tert-butoxy-1-oxohexan-2-yl)ureido)-5-tert-butoxy-5-oxopentanoic acid (432 mg, 70% pure, 0.70 mmol), AcOH (0.10 mL) and tert-butyl 2-(2-formyl-1H-imidazol-1-yl)acetate (470 mg, 2.0 mmol) in DCE (20 mL) was stirred at 75° C. for 30 min under nitrogen. The reaction mixture was cooled to 0° C., and treated with NaBH(OAc)3 (0.633 g, 3.0 mmol). The reaction was allowed to proceed overnight with stirring at room temperature. The reaction mixture was quenched with water and concentrated under reduced pressure to afford a residue which was purified by on a Biotage SP4 utilizing a gradient of 5-50% MeOH in DCM to afford (S)-4-(3-((S)-6-(bis((1-(2-tert-butoxy-2-oxoethyl)-1H-imidazol-2-yl)methyl)amino)-1-tert-butoxy-1-oxohexan-2-yl)ureido)-5-tert-butoxy-5-oxopentanoic acid (300 mg, 52%) as a colorless oil. 1H NMR (400 MHz, CDCl3) δ 6.99 (s, 2H), 6.84 (s, 2H), 4.57 (s, 4H), 4.29-4.19 (m, 2H), 3.66-3.56 (m, 4H), 2.98-2.90 (m, 2H), 2.49-2.37 (m, 4H), 1.95-1.41 (m, 42H); ESMS m/z: 410.8 (M/2+H)+.

Source