反应详情

In 500 ml of toluene, 10.2 g (0.05 mol) of N-isopropoxycarbonyl-D-valine was dissolved. Thereto were dropwise added, at −5° C., 12.4 g (0.0125 mol) of N-methylmorpholine and 6.8 g (0.05 mol) of isobutyl chlorocarbonate. Thereto was added, at −5° C., 18.3 g (0.05 mol) of (R)-1-(6-fluoro-2-benzothiazolyl)ethylamine p-toluenesulfonate. A reaction and a post-treatment were conducted in the same manner as in Reference Example 1, and the suspension of a solid in toluene was filtered to collect the solid. The solid was subjected to Soxhlet extraction for 1 week, and the extract was concentrated to obtain a solid. The solid was recrystallized from xylene to obtain 11.6 g (yield: 62.7%) of isopropyl {(R)-1-[(R)-1-(6-fluorobenzothiazol-2-yl)ethylcarbamoyl]-2-methylpropyl}carbamate. The compound obtained was confirmed for the structure by IR analysis and NMR analysis in comparison with its authentic material and identified.

1. additionThereto were dropwise added, at −5° C.
2. additionThereto was added, at −5° C.
3. customA reaction
4. filtrationwas filtered
5. customto collect the solid
6. extractionThe solid was subjected to Soxhlet extraction for 1 week
7. concentrationthe extract was concentrated
8. customto obtain a solid
9. customThe solid was recrystallized from xylene