- Catalytic Michael/Ring-Closure Reaction of α,β-Unsaturated Pyrazoleamides with Amidomalonates: Asymmetric Synthesis of (?)-Paroxetine
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A highly enantioselective tandem Michael/ring-closure reaction of α,β-unsaturated pyrazoleamides and amidomalonates has been accomplished in the presence of a chiral N,N′-dioxide–Yb(OTf)3complex (Tf: trifluoromethanesulfonyl) to give various substituted chiral glutarimides with high yields and diastereo- and enantioselectivities. Moreover, this methodology could be used for gram-scale manipulation and was successfully applied to the synthesis of (?)-paroxetine. Further nonlinear and HRMS studies revealed that the real catalytically active species was a monomeric L-PMe2–Yb3+complex. A plausible transition state was proposed to explain the origin of the asymmetric induction.
- Zhang, Yu,Liao, Yuting,Liu, Xiaohua,Yao, Qian,Zhou, Yuhang,Lin, Lili,Feng, Xiaoming
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- A synthetic Sparrow west sandbank chiral intermediates
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The invention discloses a method for synthesizing a paroxetine chiral intermediate, which comprises the following steps: reacting N-methyl malonic ester and a chiral fluorine cinnamate derivative under alkaline condition, after reaction is finished, post-treatment is carried out to obtain the paroxetine chiral intermediate. The method has the advantage that a chiral aminoalcohol compound is taken for synthesizing fluorine cinnamate as a chiral substrate, then an additive cyclization reaction is carried out with N-methyl malonic ester to obtain the chiral dioxopiperidine, the chiral aminoalcohol is simultaneously recovered, an useless enantiomer can be fully used during a paroxetine production process, environment pressure is reduced, reaction yield is high, operation is simple, raw material is easily available, reaction condition is mild, and post-treatment is simple. The reaction condition of the present invention can be used for massive preparation, the method is suitable for industrial production, and has high utility value and social economic benefit.
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Paragraph 0044-0046
(2017/07/18)
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- Intermediate for synthesizing paroxetine and preparation method for intermediate and use of intermediate
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The invention relates to the technical field of paroxetine, in particular to an intermediate for synthesizing paroxetine and a preparation method for the intermediate and use of the intermediate. The method comprises the specific step of reacting a compou
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Paragraph 0073; 0074; 0075
(2016/10/08)
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- An efficient and stereoselective synthesis of (3S,4R)-(-)-trans-4- (4′-fluorophenyl)-3-hydroxymethyl-N-methylpiperidine
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An asymmetric conjugate addition reaction between a chiral α,β-unsaturated amido ester and ethyl-N-methylmalonamide has been used as a key step in the synthesis of (3S,4R)-(-)-trans-4-(4′- fluorophenyl)-3-hydroxymethyl-N-methylpiperidine, a key intermediate for (-)-paroxetine.
- Somaiah, Sripathi,Sashikanth, Suthrapu,Raju, Veeramalla,Reddy, Karnati Venugopal
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