- Efficient synthesis of (R)-phenylephrine using a polymer-supported Corey-Bakshi-Shibata catalyst
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An efficient and mild synthetic route to (R)-phenylephrine hydrochloride using Corey-Bakshi-Shibata (CBS) catalyst was reported. In order to avoid a lengthy recovery process of the catalyst from homogeneous reaction, a polymer-supported CBS catalyst was prepared, and a preliminary attempt was made to achieve a continuous reduction on a laboratory scale, which contributes to synthesis of (R)-phenylephrine in a cost-effective way.
- Dai, Shuangxiong,Li, Guohua,Zhang, Wenbo,Zhang, Cuiyan,Song, Xiaoling,Huang, Di
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- Chiral MeCBS synthesis process
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The invention discloses a chiral MeCBS synthesis process. The process comprises the steps of adding 1.1-1.5 equivalent weight of methyl-boric acid in alkane solvent for back flow and water division, after the reaction is complete, lowering the temperature to 30-45 DEG C, after keeping static for filtration, lowering the filtered solution to below -20-0 DEG C, stirring and leaching out, after filtration and drying, acquiring the chiral MeCBS which is white solid with good fluidity. The processing method has the advantages of being simple in operation, being high in product purity, thus providing more choices in the current market with more available solvent types.
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Paragraph 0013; 0014
(2017/04/20)
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- Process for the preparation of 1,3,2-oxazaborolidine compounds
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A process is used for the preparation of 1,3,2-oxazaborolidine compounds. This process prepares compounds of formula (I) or (IA): in which: R1 is an alkyl or an aryl; and R2, R3, R4 and R5 are especially a hydrogen atom or an alkyl, wherein the following are reacted in two steps: a) a boric precursor compound with an acetal compound to give a boronate compound; and b) the boronate compound with an amino alcohol compound. This process avoids by-products and exhibits a very good stereospecificity.
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Page/Page column 7
(2008/12/06)
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- First asymmetrie synthesis of frans-3,4-dimethyl-4-arylpiperidines
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The first asymmetric synthesis of the trans-3,4-dimethyl-4-arylpiperidine opioid antagonist scaffold is reported. C-3 stereochemistry was established via CBS reduction and stereoselective anti-SN2′ cuprate displacement of the derived allylic phosphonate. The resultant vinyl bromide was then elaborated to the target compound by Suzuki coupling and frans-selective 4-methylation. Extension of this methodology should allow general enantioselective access to highly substituted piperidine ring systems.
- Furkert, Daniel P.,Husbands, Stephen M.
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p. 3769 - 3771
(2008/02/14)
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- Azabicycloalkane compounds
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This invention provides compounds of formula I: wherein R1, R2, R3, R4, R5, R6 and R7 are as defined in the specification, or a pharmaceutically acceptable salt or solvate or stereoisomer thereof. The compounds of this invention possess both β2 adrenergic receptor agonist and muscarinic receptor antagonist activity. Such compounds are useful for treating pulmonary disorders, such as chronic obstructive pulmonary disease and asthma.
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- Aryl aniline beta2 adrenergic receptor agonists
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The invention provides novel β2 adrenergic receptor agonist compounds of formula (I): wherein R1-R13 and w have any of the values described in the specification. The invention also provides combinations of such compounds and other therapeutic agents, pharmaceutical compositions comprising such compounds and combinations, methods of using such compounds to treat diseases associated with β2 adrenergic receptor activity, and processes and intermediates useful for preparing such compounds.
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- Synthesis of 3H, 14C and 13C6 labelled Sch 58235
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3H-Sch 58235 was prepared at a specific activity of 29.1 Ci/mmol by Ir(COD)(Cy3P)PyPF6 catalysed exchange with tritium gas. 14C-Sch 58235 was prepared in three steps from p-hydroxy[ring-U-14C]benzaldehyde with an overall radiochemical yield of 21%. 13C6-Sch 58235 was similarly prepared in three steps from p-hydroxy[ring-U-13C6]benzaldehyde in an overall yield of 41%. Copyright
- Hesk,Bignan,Lee,Yang,Voronin,Magatti,McNamara,Koharski,Hendershot,Saluja,Wang
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p. 145 - 155
(2007/10/03)
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