تفاعل #1994224

معادلة التفاعل

rotigotine

rotigotine

3-azidopropionic acid

pyridine

→

Rotigotine 3-Azidopropionate

المذيبات

DCM

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe solution was cooled in an ice-water bath for 5 min
2. 2
   أخرىthe bath was removed
3. 3
   workup.ADDITIONTo the solution DCC was added (778 mg, 3.73 mmol, 2.4 equiv.)
4. 4
   workup.STIRRINGto stir at room temperature under argon
5. 5
   أخرىreaction
6. 6
   ترشيحThe reaction mixture was filtered
7. 7
   تركيزthe filtrate was concentrated to dryness on a rotary-evaporator
8. 8
   أخرىThe crude product was then purified by silica gel chromatography
9. 9
   workup.DISSOLUTIONThe crude product was dissolved in a mixed solvent of hexane-ethyl acetate (6 mL, 4:1 v/v)
10. 10
    غسيلThe column was eluted with hexane-ethyl acetate (4:1 v/v)
11. 11
    أخرىevaporated by rotary-evaporation
12. 12
    أخرىdried under vacuum overnight

الإجراء التجريبي

In a 50 mL round bottom flask, rotigotine (500 mg, 1.56 mmol, 1 equiv.), 3-azidopropionic acid (447 mg, 3.73 mmol, 2.4 equiv.—in 5 mL DCM), and pyridine (302 μL, 3.73 mmol, 2.4 equiv.) were dissolved in 50 mL anhydrous DCM and allowed to stir under argon. The solution was cooled in an ice-water bath for 5 min, and the bath was removed. To the solution DCC was added (778 mg, 3.73 mmol, 2.4 equiv.). The solution was allowed to stir at room temperature under argon. Following overnight reaction, reverse phase HPLC analysis of the reaction mixture showed complete conversion of free rotigotine to the ester form. The reaction mixture was filtered and the filtrate was concentrated to dryness on a rotary-evaporator. The crude product was then purified by silica gel chromatography. The crude product was dissolved in a mixed solvent of hexane-ethyl acetate (6 mL, 4:1 v/v) and then loaded onto a 300 mL silica gel column (30 mm id). The column was eluted with hexane-ethyl acetate (4:1 v/v). The fractions (10 mL each) were analyzed by TLC and reversed phase HPLC. The product fractions were pooled, evaporated by rotary-evaporation, and then dried under vacuum overnight. Yield: 292 mg.

المصدر