- Concise Six-Step Asymmetric Approach to Ramelteon from an Acetophenone Derivative Using Ir, Rh, Cu, and Ni Catalysis
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A concise six-step asymmetric synthesis of nearly enantiomerically pure ramelteon was developed from a monocyclic precursor with a 17% overall yield and a 97% ee in the asymmetric step. The synthetically challenging tricyclic 1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan core of ramelteon was assembled by using Ir-catalyzed O-vinylation and Rh-catalyzed vinyl ether annulation through directed C-H bond activation, while the chirality was introduced with enantioselective reduction of an α,β-unsaturated nitrile moiety under hydrosilylation conditions using a CuII/Walphos type catalyst. The presented methodology represents the shortest synthetic approach to ramelteon.
- Cluzeau, Jér?me,Nettekoven, Ulrike,Kova?evi?, Miroslav Planinc,?asar, Zdenko
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p. 2129 - 2135
(2021/10/20)
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- PROCESS FOR THE PREPARATION OF RAMELTEON
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A process is described for the preparation on an industrial scale of N-[2-(8S)-1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl]ethyl]propionamide, ramelteon, having the structure illustrated below:
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Page/Page column 10-11
(2010/09/18)
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- PROCESS FOR THE PREPARATION OF RAMELTEON
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A process is described for the preparation on an industrial scale of N-[2-(8S)- 1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl] propionamide, ramelteon, having the structure illustrated below: (I).
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Page/Page column 24
(2010/10/03)
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- SYNTHESIS OF (S)-N-[2-(1,6,7,8-TETRAHYDRO-2H-INDENO-[5,4-B]FURAN-8-YL)ETHYL]PROPIONAMIDE
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The present invention relates in general to the field of organic chemistry and in particular to the preparation of (S)-N-[2-(1,6,7,8-tetrahydro-2H-indeno-[5,4-b]furan-8-yl)ethyl]propionamide, i.e. ramelteon, and analogues thereof.
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Page/Page column 23
(2010/09/03)
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- PROCESS FOR THE SYNTHESIS OF RAMELTEON AND ITS INTERMEDIATES
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The present invention provides processes and intermediates for the synthesis of ramelteon.
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Page/Page column 42
(2010/04/30)
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- PROCESS FOR PREPARATION OF (S)-N-[2-(1,6,7,8-TETRAHYDRO-2H-INDENO[5,4-B]FURAN-8-YL)ETHYL] PROPIONAMIDE AND NOVEL INTERMEDIATES THEREOF
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Disclosed herein process for preparation of (S)-Ramelteon and intermediates thereof.
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Page/Page column 32
(2010/04/28)
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- PROCESS FOR PREPARING RAMELTEON.
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The invention relates to an improved process for preparing indane derivatives including, for example, ramelteon. The invention provides a process for preparing ramelteon from a compound of formula (II), wherein the process comprises successive reduction reactions and converting a compound of formula (IV) to ramelteon: The invention further relates to an improved process for converting a compound of formula (IV) to ramelteon.
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Page/Page column 7-8
(2009/10/21)
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