- A preparing method of a penem medicine mercaptan branch chain
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A preparing method of a penem medicine mercaptan branch chain is disclosed. The method includes reacting an intermediate that is (2S,4R)-4-(3-fluorophenylthio)pyrrolidine-2-carboxylic acid with a fluorizating agent to prepare a mercaptan intermediate that is (2S,4S)-4-mercaptopyrrolidine-2-carboxylic acid, and performing amino protection and carboxyl amidation to obtain the penem medicine mercaptan branch chain that is (2S,4S)-1-p-nitrobenzyloxycarbonyl-2-(N,N-dimethylaminoacyl)-4-mercaptopyrrolidine. Compared with the prior art, the method omits a hydroxy protection step in mercaptan preparation, simplifies the synthesis route, and is high in yield, low in cost and suitable for large-scale industrial production.
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- A penem medicine intermediate and a preparing method thereof
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A penem medicine intermediate and a preparing method thereof are provided. The penem medicine intermediate is (2S,4R)-4-(3-fluorophenylthio)pyrrolidine-2-carboxylic acid (shown as the formula IV). The intermediate is prepared by a one-step reaction by subjecting trans-4-hydroxy-L-proline and 3,3'-difluoro diphenyl disulfide which are adopted as initial raw materials to disulfide bond breaking under actions of a reductant. The intermediate is simple in preparing method, easily available in raw materials, low in environment pollution and suitable for large-scale industrial production, and can be used for preparing penem medicine mercaptan branch chains or penem medicines.
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- AN IMPROVED PROCESS FOR THE PREPARATION OF PYRROLIDINE THIOL DERIVATIVES USEFUL IN THE SYNTHESIS OF CARBAPENEM COMPOUNDS
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The present invention relates to an improved process for the preparation of the compound of formula (III) which is used in the synthesis of carbapenem antibiotics. wherein R3 is hydrogen or an amine protecting group.
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Page/Page column 10
(2012/09/11)
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- AN IMPROVED PROCESS FOR THE PREPARATION OF MEROPENEM
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The present invention provides an improved process for the preparation of methyl carbapenem derivative of formula (I) or its pharmaceutically acceptable salts or hydrates thereof in a pure form.
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- AN IMPROVED PROCESS FOR THE PREPARATION OF CARBAPENEM ANTIBIOTIC
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The present invention relates to an improved process for the preparation of the carbapenem antibiotic of formula (I) or its salts, hydrates and esters. The present invention further provides novel crystalline form of compound of general formula (III), wherein R3 is p-nitrobenzyloxy carbonyl.
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Page/Page column 22
(2010/09/17)
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- A PROCESS FOR THE PREPARATION OF THE INTERMEDIATE OF Β-METHYL CARBAPENEM
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A process of preparation of the intermediate of β-methyl carbapenem is disclosed, in which 4-acetylazacyclobutanone as the raw material is firstly reacted with α-bromopropionamide having a big inductive group. Since this reaction is highly stereoselectivity, most of the product is the required parent nucleus of β-methyl carbapenem, a product of β-configuration. Compared with the prior art, the process of the present invention is highly-yielding, cost-effective and can be used for large scale production.
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Page/Page column 17
(2010/11/28)
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- A PROCESS FOR THE PREPARATION OF MEROPENEM
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The invention relates to a process for the preparation of meropenem, a β-methylcarbopenem. The said process comprises the following steps: preparing the compound of Formula (XI) from the compound of Formula (IV) through three steps "one-pot process"; then condensing the compound of Formula (XI) with the compound of Formula (XX) to form the compound of Formula (XXIV); finally preparing meropenam of Formula (I) from the compound of Formula (XXIV) by deprotection reaction by means of catalyst. The process of the invention is easily to carry out, the product is isolated in high content and yield, and the cost is reduced, thereby overcoming the shortage of the prior art.
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Page/Page column 19-20
(2010/11/28)
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- A PROCESS FOR THE PREPARATION OF CARBAPENEM COMPOUNDS
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The present invention relates to an improved process for the preparation of carbapenem compounds.
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Page/Page column 11-12
(2008/06/13)
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- PROCESSES FOR THE PREPARATION OF CARBAPENEMS
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The invention relates to processes for the preparation of carbapenems. More particularly, it relates to a process for the preparation of meropenem.
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Page/Page column 6
(2010/11/28)
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- Deacetylation of thioacetate using acetyl chloride in methanol
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A highly efficient method for the deacetylation of thioacetate is reported under mild acidic conditions employing acetyl chloride in methanol. Some of the major advantages are mild conditions, high efficiency, high yields, and easy operations. Copyright Taylor & Francis Group, LLC.
- Tewari, Neera,Nizar, Hashim,Mane, Avinash,George, Vinod,Prasad, Mohan
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p. 1911 - 1914
(2007/10/03)
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- An Efficient Synthesis of (2S,4S)-2-Substituted-4-mercaptopyrrolidine Derivatives
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An efficient synthesis of (2S,4S)-2-substituted 4-mercapto-1-p-nitrobenzyloxycarbonylpyrrolidine (2) was studied.Intramolecular cyclization of (2S,4R)-1-p-nitrobenzyloxycarbonyl-4-methanesulfonyloxy-2-pyrrolidinethiocarboxylic acid (8), derived from trans-4-hydroxy-L-proline (3), afforded (1S,4S)-5-p-nitrobenzyloxycarbonyl-2-thia-5-azabicycloheptan-3-one (7).Reaction of 7 with primary amine, secondary amine and alkoxide afforded corresponding 2 in high yield.
- Matsumura, Haruki,Bando, Takashi,Sunagawa, Makoto
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p. 147 - 160
(2007/10/02)
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