反应详情

2.7 g (8 mmoles) of the product of Example 15 are dissolved in 100 ml of anhydrous tetrahydrofuran; the resulting solution is added first with 2.42 g (24 mmoles) of anhydrous triethylamine, then, after cooling to 0°-5° C., with 1.6 g (17 mmoles) of methyl chloroformate. The reaction is complete within 3 hours, keeping room temperature. After that, solvent is evaporated off under reduced pressure and the residue is washed with acidulated water, the product is filtered, washed and crystallized from ethyl ether. M.p. 200°-202° C.

1. customkeeping room temperature
2. customAfter that, solvent is evaporated off under reduced pressure
3. washthe residue is washed with acidulated water
4. filtrationthe product is filtered
5. washwashed
6. customcrystallized from ethyl ether