反应详情

A mixture of docosanoic acid (500 mg) and thionyl chloride (2 ml) in benzene (5 ml) was refluxed for 1 hour. After removal of the solvent under reduced pressure, the residue was taken up in benzene and benzene was evaporated off. This operation was repeated three times to give crude docosanoyl chloride. Meanwhile, a solution of dibenzyl N-(N-tert-butoxycarbonyl-L-valyl)-L-glutamate (773 mg) and anisole (0.25 ml) in trifluoroacetic acid (1 ml) was stirred at 0° C. for 1 hour. Evaporation of trifluoroacetic acid under reduced pressure gave a residue which was taken up in benzene. Benzene was distilled off by using a high vacuum pump. This operation was repeated three times to leave crude dibenzyl N-(L-valyl)-L-glutamate, which was dissolved in tetrahydrofuran (5 ml). To this solution were added triethylamine (0.7 ml) and a solution of docosanoyl chloride prepared as mentioned above in tetrahydrofuran (3 ml). After the resulting mixture was stirred at room temperature for 3 hours, the solvent was removed under reduced pressure, and the residue was dissolved in chloroform. The chloroform solution was washed with 1N sodium hydroxide solution, 1N hydrochloric acid solution, and an aqueous solution of sodium bicarbonate successively, and then dried over magnesium sulfate. After evaporation of the solvent, the residue was purified by being subjected to a silica gel column chromatography. Elution with chloroform and an usual work-up afforded dibenzyl N-(N-docosanoyl-L-valyl)-L-glutamate (520 mg, powder).

1. temperaturewas refluxed for 1 hour
2. customAfter removal of the solvent under reduced pressure
3. custombenzene was evaporated off
4. customto give crude docosanoyl chloride
5. customEvaporation of trifluoroacetic acid under reduced pressure
6. customgave a residue which
7. distillationBenzene was distilled off
8. customto leave crude dibenzyl N-(L-valyl)-L-glutamate, which
9. customthe solvent was removed under reduced pressure
10. dissolutionthe residue was dissolved in chloroform
11. washThe chloroform solution was washed with 1N sodium hydroxide solution, 1N hydrochloric acid solution
12. dry with materialan aqueous solution of sodium bicarbonate successively, and then dried over magnesium sulfate
13. customAfter evaporation of the solvent
14. customthe residue was purified
15. washElution with chloroform