反应详情

Pitavastatin, its calcium salt (2:1) and its lactone are disclosed in three related U.S. patents (U.S. Pat. Nos. 5,011,930 A, 5,856,336 A and 5,872,130 A). In the 930' patent, pitavastatin sodium is prepared by converting ethyl (E)-3,5-dihodroxy[4′-(4″-fluorophenyl)-2′-(I cyclopropyl)-quinolin-3′-yl]-hept enoate, to the sodium salt in accordance to Example 2 by using an aqueous solution of sodium hydroxide. The compound is dissolved in ethanol, to which an aqueous solution of sodium hydroxide is added. The resulting mixture is stirred and the ethanol is removed under reduced pressure. Water is then added, and the mixture is further extracted with ether. The aqueous layer is then lyophilized to obtain the final product, or the aqueous layer is weakly acidified with a dilute solution of hydrochloric acid. The acidified aqueous layer is then extracted with ether. After extraction, the ether layer is dried over magnesium sulphate. Then the ether is removed under reduced pressure to obtain the sodium salt. The '930 patent and its related patents do not disclose the procedure for preparing the calcium salt of pitavastatin, and do not disclose amorphous or crystalline forms of pitavastatin calcium as well.

1. additionis added
2. customthe ethanol is removed under reduced pressure
3. additionWater is then added
4. extractionthe mixture is further extracted with ether