反应详情

温度

-15 °C

In 25 ml of dimethylformamide was dissolved 2.65 g of N-benzyloxycarbonyl-L-leucine. After cooling to -15° C., 1.10 ml of N-methylmorpholine and then 1.37 ml of isobutyl chloroformate were added to the solution while stirring the solution at the same temperature. The mixture was sitrred at -15° C. for 5 minutes. On the other hand, 3.25 g of L-argininal dibutyl acetal hydrochloride (Example 2) was dissolved in 30 ml of dimethylformamide and 1.40 ml of triethylamine was added to the solution. The resulting solution was dropwise added at -10° C. to the mixed acid anhydride suspension which had been previously prepared. Stirring was continued at the same temperature for an hour and then at 0° C. for an hour. The resulting reaction solution was concentrated under reduced pressure and the residue was dissolved in 100 ml of chloroform. The solution was washed successively with 10% citric acid aqueous solution (30 ml×2), saturated sodium chloride aqueous solution (30 ml×1), saturated sodium hydrogencarbonate aqueous solution (30 ml×2) and saturated sodium chloride aqueous solution (30 ml×2). After drying over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure. The obtained residue was subjected to column chromatography using silica gel as a carrier and developed with chloroform: methanol=20:1 (v/v). The fraction showing Rf: 0.48 (under the same conditions as in Example 1 (A) 4) which was positive in the Sakaguchi reaction, was concentrated under reduced pressure to give 3.73 g of N-benzyloxycarbonyl-L-leucyl-L-argininal dibutyl acetal.

1. customhad been previously prepared
2. stirringStirring
3. waitwas continued at the same temperature for an hour
4. waitat 0° C. for an hour
5. customThe resulting reaction solution
6. concentrationwas concentrated under reduced pressure
7. dissolutionthe residue was dissolved in 100 ml of chloroform
8. washThe solution was washed successively with 10% citric acid aqueous solution (30 ml×2), saturated sodium chloride aqueous solution (30 ml×1), saturated sodium hydrogencarbonate aqueous solution (30 ml×2) and saturated sodium chloride aqueous solution (30 ml×2)
9. dry with materialAfter drying over anhydrous magnesium sulfate
10. distillationthe solvent was distilled off under reduced pressure
11. customwas positive in the Sakaguchi reaction
12. concentrationwas concentrated under reduced pressure