反应详情

250 mg (1.19 mmol) of the compound from Example 3A, 122 mg (0.99 mmol) of the compound from Example 1A and 23 mg (99 μmol) camphor-10-sulfonic acid are dissolved in 5 ml anhydrous ethanol and the mixture is heated under reflux overnight. Thereafter, the reaction mixture is allowed to cool and is pre-purified by means of preparative HPLC (RP18 column; mobile phase: acetonitrile/water gradient) and subsequent flash chromatography over silica gel (mobile phase: methylene chloride/methanol gradient). Renewed purification by means of preparative HPLC (RP18 column; mobile phase: acetonitrile/water gradient) finally gives 21 mg (9% of th.) of the title compound.

1. temperaturethe mixture is heated
2. temperatureunder reflux overnight
3. temperatureto cool
4. customis pre-purified by means of preparative HPLC (RP18 column; mobile phase: acetonitrile/water gradient) and subsequent flash chromatography over silica gel (mobile phase: methylene chloride/methanol gradient)
5. custompurification by means of preparative HPLC (RP18 column; mobile phase: acetonitrile/water gradient) finally gives 21 mg (9% of th.) of the title compound