160707-36-8Relevant articles and documents
PROCESSES AND INTERMEDIATES FOR PREPARING 2-SUBSTITUTED PIPERIDINE STEREOISOMERS
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Page/Page column 5, (2008/06/13)
A process for preparing d-threo methyl ±- piperid-2-ylarylacetates of formula III: wherein R 1 is aryl having 6 to 28 carbon atoms, comprising the steps of: reacting a pyridine having formula I: wherein R 1 is aryl having 6 to 28 carbon atoms with hydrogen in an alkanoic acid having 1 to 10 carbon atoms and in the presence of a catalyst to provide a mixture of threo and erythro piperidine stereoisomers having formulas IIa-d: €?€?€? adding an alkyl alkanoate having 2 to 20 carbon atoms to said mixture, thereby precipitating alkanoate salts of said erythro stereoisomers preferentially with respect to alkanoate salts of said threo stereoisomers; reacting said erythro alkanoate salts with aqueous base to form said erythro stereoisomers; reacting said erythro stereoisomers with an acid resolving agent in an alkyl alcohol having 1 to 5 carbon atoms, thereby forming acid salts of said 1-erythro stereoisomers preferentially with respect to said d-erythro stereoisomers; reacting said 1-erythro acid salts with aqueous base to form said 1-erythro piperidine; reacting said 1-erythro piperidine with an alkali metal alkoxide having one to 10 carbon atoms in organic solvent, whereby forming said d-threo piperidine, and converting said d-threo piperidine to said d-threo methyl ±- piperid -2- ylarylacetate.
Processes and intermediates for resolving piperidyl acetamide stereoisomers
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, (2008/06/13)
Processes and intermediates for preparing 2-substituted piperidines such as 2-substituted d-threo piperidines are provided, including processes and intermediates for resolution of piperidyl acetamide stereoisomers.