4-Methylmorpholine → (R,S)-Benthiavalicarb-isopropyl

Participants

Reaction Steps

In 250 ml of toluene, 13.4 g (0.066 mol) of N-isopropoxycarbonyl-D-valine was dissolved. Thereto was added 14.3 g (0.144 mol) of N-methylmorpholine. Then was dropwise added at −10° C., 8.6 g (0.063 mol) of isobutyl chlorocarbonate. Thereto was added 22 g (0.06 mol) of (S)-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 hot toluene solution was filtered in a hot state to remove the insoluble matter. The filtrate was cooled, whereby crystals were precipitated. The crystals were collected by filtration and dried to obtain 15.8 g (yield: 69.3%) of isopropyl {(R)-1-[(S)-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.

Provenance & Evidence