反应详情

温度

0 °C

10.1 g of t-butoxycarbonylisoleucylhistidine hydrochloride and 6.3 g of prolylserine methyl ester hydrochloride are dissolved in 100 ml of dimethylformamide. The solution is cooled to 0° C. To the solution is added 3.4 g of 1-hydroxybenzotriazole, 2.8 ml of N-methylmorpholine and 7.6 g of dicyclohexylcarbodiimide. The reaction mixture is stirred for two hours at 0° C. and then is allowed to stand at 4° C. for sixteen hours. Dicyclohexylurea is filtered from the reaction mixture and is washed with acetone. 300 ml of ethyl acetate is added to the solution. The solution is extracted three times with 300 ml saturated potassium bicarbonate and two times with 300 ml of brine. The product is extracted into 300 ml of 2 M potassium bisulfate. The acidic solution is neutralized with potassium carbonate. The slightly basic aqueous solution is extracted three times with 300 ml of methylene chloride. The methylene chloride solution, which contains the product, is dried over sodium sulfate, filtered and stripped of solvent under vacuum. The residue is dissolved in 100 ml of ethyl acetate. The solution is added to 1 liter of cold rapidly stirring Skellysolve B. The white precipitate was filtered and dried under vacuum at 55° C. to afford the product t-butoxycarbonylisoleucylhistidylprolylserine methyl ester.

1. waitto stand at 4° C. for sixteen hours
2. filtrationDicyclohexylurea is filtered from the reaction mixture
3. washis washed with acetone
4. addition300 ml of ethyl acetate is added to the solution
5. extractionThe solution is extracted three times with 300 ml saturated potassium bicarbonate and two times with 300 ml of brine
6. extractionThe product is extracted into 300 ml of 2 M potassium bisulfate
7. extractionThe slightly basic aqueous solution is extracted three times with 300 ml of methylene chloride
8. dry with materialis dried over sodium sulfate
9. filtrationfiltered
10. dissolutionThe residue is dissolved in 100 ml of ethyl acetate
11. additionThe solution is added to 1 liter of cold rapidly stirring Skellysolve B
12. filtrationThe white precipitate was filtered
13. customdried under vacuum at 55° C.