反应详情

2.43 g (8.62 mmol) of the compound from Example 2A, 1.53 g of the compound from Example 16A and 182 mg (784 μmol) camphor-10-sulfonic acid are dissolved in 35 ml anhydrous methanol and the mixture is heated under reflux overnight. After cooling, the mixture is concentrated, the residue is taken up again in 325 ml methanol, 0.5 ml (8.62 mmol) of a 25% strength methanolic sodium methylate solution is added and the mixture is heated again under reflux overnight. After cooling, the precipitate formed is filtered off with suction, washed with diethyl ether and suspended in a little water, an excess of 1 M hydrochloric acid is added and the suspension is concentrated again. The residue is washed with water and diethyl ether and dried. 1.34 g (43% of th.) of the title compound are obtained.

1. temperaturethe mixture is heated
2. temperatureunder reflux overnight
3. temperatureAfter cooling
4. concentrationthe mixture is concentrated
5. addition0.5 ml (8.62 mmol) of a 25% strength methanolic sodium methylate solution is added
6. temperaturethe mixture is heated again
7. temperatureunder reflux overnight
8. temperatureAfter cooling
9. customthe precipitate formed
10. filtrationis filtered off with suction
11. washwashed with diethyl ether
12. additionan excess of 1 M hydrochloric acid is added
13. concentrationthe suspension is concentrated again
14. washThe residue is washed with water and diethyl ether
15. customdried