- Method for preparing (1R, 3S)-3-aminocyclopentanol hydrochloride
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The invention discloses a method for preparing (1R, 3S) 3-aminocyclopentanol hydrochloride, belongs to the field of organic chemical synthesis, and provides a process route to overcome the defects ofhigh price, difficulty in chiral control and the like in the prior art. The process route comprises the following steps: 1) oxidizing tert-butyl carbonate hydroxylamine into tert-butyl carbonate nitrosyl under the catalysis of copper chloride and 2-ethyl-2-oxazoline, then carrying out a hetero Diels-Alder reaction with cyclopentadiene in situ; 2) selectively reducing nitrogen-oxygen bonds in a zinc powder-acetic acid reaction system; 3) under the catalysis of lipase, reacting with vinyl acetate to optically and selectively realize chiral resolution; 4) reducing double bonds through palladium carbon hydrogenation; 5) under the alkaline condition of lithium hydroxide-methanol, performing deacetylation protection; and 6) removing tert-butyl carbonate protection in a hydrogen chloride isopropanol acid solution prepared from acetyl chloride and isopropanol in situ, and forming hydrochloride in situ to obtain a target product. The synthetic method has the beneficial effects that the synthetic method has the characteristics of novel and short route, high optical purity, low cost and the like.
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Paragraph 0030; 0046-0048; 0054-0058
(2021/03/31)
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- Preparation method of (1R,3S)-3-amino-1-cyclopentanol and salt thereof
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The invention discloses a preparation method of (1R,3S)-3-amino-1-cyclopentanol and a salt thereof, and relates to the field of organic synthesis. In the method, a chiral source in an N-Acyl hydroxylamine compound is used as chiral induction, and an asymm
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- Preparation method of (1R, 3S)-3-amino-1-cyclopentanol hydrochloride
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The invention provides a preparation method of (1R, 3S)-3-amino-1-cyclopentanol hydrochloride. A target compound is synthesized through a chiral induction method, and specifically, cheap chiral hydroxy acid is used as a raw material and reacted with hydro
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Paragraph 0024
(2019/12/29)
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- A (1 R, 3 S) -3 - amino-cyclopentanol hydrochloride preparation method (by machine translation)
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The invention discloses a (1 R, 3 S) - 3 - amino-cyclopentanol hydrochloride of the preparation method, the method using chiral carboxylic acid with hydroxylamine to form the amide as chiral source, in copper catalyzed oxidation in the reaction system to rapidly obtain a chiral Diels - alder reaction product, after passes through the reduction reaction and alkaline deprotection reaction, and acidified after reaction to obtain the target product. Chiral inducing reagent chiral carboxylic acid by simple acidification, extraction processing can be reclaimed and reused. This kind of (1 R, 3 S) - 3 - amino-cyclopentanol hydrochloride preparation method has high operation safety and high selectivity, raw materials are easy, and the cost is low, the reaction time is short and simple process flow and the like. (by machine translation)
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- Intermediate for preparing bictegravir and preparation method thereof
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The invention relates to the technical field of a drug, and concretely relates to an intermediate for preparing bictegravir and a preparation method thereof. The present invention provides two novel types of compounds and three routes for preparation of a compound (VI). Through substrate induction, chiral catalysis or synergistic effect of substrate induction and chiral catalysis, the stereoselectivity of a Diels-Alder reaction can be greatly improved, and a high chiral purity of a common intermediate (III) can be obtained; cut-out of N-O bond and reduction the double bond use catalytic hydrogenation, which can be environmentally friendly; the reaction conditions are mild, the yield is higher than the existing preparation method, the method is economic and effective, and is adapted to large-scale industrial production.
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- Preparation method of (1R,3S)-3-amino cyclopentanol hydrochloride
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The invention provides a preparation method of (1R,3S)-3-amino cyclopentanol hydrochloride. A urea peroxide-trifluoroacetic anhydride system is adopted as an oxidizing agent, and a compound I is subjected to oxidation reaction so as to generate a compound II and a compound II', so that the use of an oxidizing agent with high price and big risk is avoided. Hydrogen chloride obtained through esterification reaction of isopropanol and an acyl chloride compound is subjected to de-protection reaction with a compound III, so that the process stability is good compared with the way of directly feeding hydrogen chloride and carrying out de-protection reaction on the hydrogen chloride and the compound III, the condition that the (1R,3S)-3-amino cyclopentanol hydrochloride can be smoothly separatedout from a reaction solution is ensured, and the method is convenient to operate and friendly to the work environment. In addition, the preparation method provided by the invention is high in productyield and purity, low in production cost, high in safety, simple to operate, and suitable for large-scale production.
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Paragraph 0080; 0083; 0085; 0088; 0089; 0092; 0093; 0096
(2018/12/02)
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