Reaction #969873

Reaction equation

Z-Val-Pro-Val-Pro-OH

1-hydroxibenzotriazol

N,N′-diisopropylcarbodiimide

Ara-C

→

Z-Val-Pro-Val-Pro Ara-C

Yield 22.0%

Solvents

dimethylformamide

Conditions

Workup

1. 1
   Otherwas continued until complete disappearance of the starting material (overnight)
2. 2
   OtherThen, the solvent was evaporated
3. 3
   workup.DISSOLUTIONthe residue was dissolved in ethyl acetate
4. 4
   Washwashed with citric acid (10%), NaHCO3 (10%) and brine
5. 5
   DryingThe organic layer was dried (Na2SO4)
6. 6
   Otherevaporated to dryness
7. 7
   Otherleaving a residue that
8. 8
   Otherwas purified by CCTLC on the chromatotron with dichloromethane:methanol (20:1)
9. 9
   Otherto give D (22% yield)

Procedure

A solution of Z-Val-Pro-Val-Pro-OH [SEQ ID NO:9] (134.4 mg, 0.24 mmol) in dimethylformamide (1.5 mL), was successively treated at room temperature with 1-hydroxibenzotriazol (33.3 mg, 0.24 mmol), N,N′-diisopropylcarbodiimide (38.4 μL, 0.24 mmol) and Ara-C (50 mg, 0.20 mmol). The stirring was continued until complete disappearance of the starting material (overnight). Then, the solvent was evaporated, and the residue was dissolved in ethyl acetate and washed with citric acid (10%), NaHCO3 (10%) and brine. The organic layer was dried (Na2SO4) and evaporated to dryness leaving a residue that was purified by CCTLC on the chromatotron with dichloromethane:methanol (20:1) to give D (22% yield)

Source