反应详情

250 ml of methanol are cooled to −10° C., 25 ml of acetyl chloride are added rapidly and the solution is allowed to return to room temperature. The compound of formula (V) obtained in Example 2 is then added and is left stirring overnight at room temperature. The solvent is concentrated under vacuum at room temperature, the residue is taken up in 100 ml of methanol and the solvent is concentrated again under vacuum. The residue is taken up in 100 ml of ethyl acetate and the solvent is concentrated under vacuum, and this operation is repeated entirely three times. The residue is taken up in 150 ml of ethyl acetate and left stirring for two hours at room temperature, and the precipitate formed is spin-filtered off, washed with ethyl acetate and dried under vacuum. 32.4 g of the expected product are obtained.

1. customto return to room temperature
2. waitis left
3. concentrationThe solvent is concentrated under vacuum at room temperature
4. concentrationthe solvent is concentrated again under vacuum
5. concentrationthe solvent is concentrated under vacuum
6. waitleft
7. stirringstirring for two hours at room temperature
8. customthe precipitate formed
9. filtrationis spin-filtered off
10. washwashed with ethyl acetate
11. customdried under vacuum