- Pitavastatin calcium method for the preparation of intermediates
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The invention discloses a preparation method for a pitavastatin calcium intermediate shown in the formula (I) of the Specification. According to the invention, the pitavastatin calcium intermediate is prepared from ester compounds shown in the formula (II) of the Specification through hydrolysis and reduction; alcohol is used as hydrolysis medium, alcoholate can be formed by the alcohol and hydroxide, and the alkalinity of the alcoholate is stronger than that of the hydroxide, so that hydrolysis reaction is relatively facilitated; the hydrolysis time is 3-4 days when the hydrolysis medium in the prior art is an aqueous solution, while the hydrolysis time of the preparation method provided by the invention is less than 20 h.
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Page/Page column 0039; 0040
(2017/01/23)
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- A NOVEL SYNTHETIC METHOD OF HMG-CoA REDUCTASE INHIBITOR NK-104 VIA HYDROBORATION-CROSS COUPLING SEQUENCE
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The regioselective hydroboration of ethyl (3R,5S)-3,5-isopropylidenedioxy-6-heptynoate, followed by the cross-coupling reaction with an aryl halide, provides ethyl (3R,5S,6E)-7-aryl-3,5-isopropylidenedioxy-6-heptenoate, a precursor of a highly potent HMG-
- Miyachi, Nobuhide,Yanagawa, Yoshinobu,Iwasaki, Hiroshi,Ohara, Yoshio,Hiyama, Tamejiro
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p. 8267 - 8270
(2007/10/02)
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