- Preparation method of statins intermediate
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The invention discloses a preparation method of a statins intermediate, comprising the following steps: a phosphate compound and an aldehyde compound are subjected to a condensation reaction under theaction of a catalyst and alkali; after the reaction, post-treatment is conducted to obtain the statins intermediate. The statins intermediate includes a rosuvastatin intermediate (Compound A) and a pitavastatin calcium intermediate (Compound B). The preparation method has the advantages of low cost, simple operation and good yield, is environmentally friendly, and is suitable for industrial production.
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Paragraph 0047-0050
(2018/11/27)
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- Pitavastatin calcium method for the preparation of
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The invention relates to a preparation method of a cholesterol reduction drug, particularly relates to a preparation method of pitavastatin calcium as a crude drug of the cholesterol reduction drug, and aims at the problems that the pitavastatin calcium synthetic technology in the prior art is long in steps and complicated in operation, and uses strongly corrosive reagents which is environmentally unfriendly, causes serious corrosion to equipment, and may not facilitate industrial production. The invention provides the new preparation method of the pitavastatin calcium, the new preparation method is as follows: 3-bromomethyl-2-cyclopropyl-4-(4-fluorophenyl)quinoline is prepared from 2-cyclopropyl-4-(4-fluorophenyl)-3-quinolinecarboxaldehyde by a one step reaction, and then reacts with an organophosphorus reagent to obtain pitavastatin calcium intermediate phosphorus ylide, on the basis of improving of the yield to 80%, the reaction steps are reduced, and the reaction difficulty is reduced, and hydroxylamine hydrochloride is selected as a deprotection reagent, so that the new preparation method is mild in reaction conditions, environmentally friendly, high in yield, and beneficial to industrial production.
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Paragraph 0061-0066
(2017/03/14)
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- The use of a lactonized statin side-chain precursor in a concise and efficient assembly of pitavastatin
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A concise and simple synthetic route to pitavastatin is described. The approach involves a highly stereoselective Wittig olefination reaction between a lactonized statin side-chain precursor and the triphenylphosphonium bromide salt of the corresponding quinoline heterocyclic core. The necessary O-tert-butyl(dimethyl)silyl-protected pitavastatin lactone was obtained in 75% yield and high purity by simple crystallization from aqueous methanol. Subsequent deprotection, hydrolysis, and cation exchange in a one-pot operation provided pitavastatin calcium in 93% yield. Georg Thieme Verlag Stuttgart · New York.
- Fabris, Jan,Casar, Zdenko,Smilovic, Ivanagazi
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experimental part
p. 1700 - 1710
(2012/07/27)
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- Synthesis of artificial HMG-CoA reductase inhibitors based on the olefination strategy
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Synthetic methods were studied for optically active 6-oxo-3,5-isopropylidenedioxyhexanoate esters (4), which could be used as a key precursor of various kinds of artificial analogs of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. An enantiomer (+)-4 was prepared by asymmetric reduction of β,δ-diketo esters derived from the Taber's alcohol or L-tartrate followed by a series of chemical transformations, and the desired enantiomer (-)-4 was prepared by the same asymmetric reduction starting from D-tartrate. The key intermediate (-)-4 was finally converted into a highly potent HMG-CoA reductase inhibitor, NK-104.
- Hiyama,Minami,Takahashi
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p. 364 - 372
(2007/10/02)
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