51072-34-5Relevant articles and documents
Asymmetric Synthesis of a Key Dextromethorphan Intermediate and Its Analogues Enabled by a New Cyclohexylamine Oxidase: Enzyme Discovery, Reaction Development, and Mechanistic Insight
Chen, Fener,Huang, Zedu,Li, Zhining,Lin, Juan,Wang, Jiaqi,Wang, Zexu,Wu, Xiaofan
supporting information, p. 5598 - 5614 (2020/05/19)
(S)-1-(4-Methoxybenzyl)-1,2,3,4,5,6,7,8-octahydroisoquinoline [(S)-1-(4-methoxybenzyl)-OHIQ, (S)-1a] is a key synthetic intermediate in the industrial production of dextromethorphan, one of the most widely used over-the-counter antitussives. We report here that a new cyclohexylamine oxidase discovered by genome mining, named CHAOCCH12-C2, was able to completely deracemize 100 mM 1a under Turner's deracemization conditions to afford (S)-1a in 80% isolated yield and 99% ee at a semipreparative scale (0.4 mmol). When this biocatalytic reaction was scaled up to a gram scale (5.8 mmol), without reaction optimization (S)-1a was still isolated in 67% yield and 96% ee. The relatively higher kcat determined for CHAOCCH12-C2 was rationalized as one major factor rendering this enzyme capable of oxidizing 1a effectively at elevated substrate concentrations. Protein sequence alignment, analysis of our co-crystal structure of CHAOCCH12-C2 complexed with the product 1-(4-methoxybenzyl)-3,4,5,6,7,8-hexahydroisoquinoline [1-(4-methoxybenzyl)-HHIQ, 2a], and the structure-guided mutagenesis study together indicated L295 is one of the critical residues for this efficient enzymatic oxidation process and supported the presence of two cavities as well as a catalytically important "aromatic cage" formed by F342, Y433, and FAD. The synthetic applicability of CHAOCCH12-C2 was further underscored by the stereoselective synthesis of various enantioenriched 1-benzyl-OHIQ derivatives of potential pharmaceutical importance at a semipreparative scale.
A process for preparing dextromethorphan method
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Paragraph 0177-0179, (2018/02/04)
The invention relates to a novel method for preparing dextromethorphan. When the method is used for preparing an intermediate (+)-1-(4-methoxy) benzyl-1,2,3,4,5,6,7,8-hexahydroisoquinoline (VI), a catalytic reducing method is adopted to carry out chiral reduction on 1-(4-methoxy) benzyl-3,4,5,6,7,8-hexahydroisoquinoline (VI), so that the intermediate is prepared with high selectivity. The novel method disclosed by the invention can cancel complex operations such as chiral resolution, is simple to operate, gentle in reaction condition, short in total time, wide in material source, and very suitable for industrially producing dextromethorphan.
GENERAL ASYMMETRIC SYNTHESIS OF BENZOMORPHANS AND MORPHINANS VIA ENANTIOSELECTIVE HYDROGENATION
Kitamura, M.,Hsiao, Yi,Noyori, R.,Takaya, H.
, p. 4829 - 4832 (2007/10/02)
A variety of optically active benzomorphans including metazocine and pentazocine as well as dextromethorphan, a morphinan, are obtainable by using the BINAP-ruthenium(II) catalyzed enantioselective hydrogenation as key operation.
