57849-23-7Relevant articles and documents
Racemization recovery method of dextromethorphan hydrobromide intermediate byproducts
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, (2021/01/25)
A racemization recovery method of dextromethorphan hydrobromide intermediate byproducts comprises the following steps: 1) performing mother liquor treatment: under a stirring condition, carrying out reduced pressure distillation until methanol is basically evaporated completely, when the temperature of the concentrated mother liquor is lower than 40 DEG C, adding a sodium hydroxide solution, stirring, standing, detecting that the pH value is greater than 12, layering, recovering mandelic acid by using the obtained water phase, concentrating the obtained oil phase under reduced pressure until toluene is completely evaporated, and cooling to 65-80 DEG C; 2) performing N-chlorination: adding isopropanol, and dropwise adding a sodium hypochlorite solution; 3) performing racemization: adding liquid caustic soda into the reaction system, and stirring for reaction; 4) reducing: dropwise adding a sodium borohydride solution, and reacting completely; 5) performing chiral resolution: adding methanol and D-mandelic acid into the toluene solution of a compound (I), and carrying out chiral resolution; and (6) refining the mother liquor: treating the mother liquor obtained in step (5) as a raw material according to the treatment methods in steps (1)-(4) to obtain a mother liquor prepared compound (I) methylbenzene solution, and adding oxalic acid for refining.
Imine Reductase-Catalyzed Enantioselective Reduction of Bulky α,β-Unsaturated Imines en Route to a Pharmaceutically Important Morphinan Skeleton
Yao, Peiyuan,Xu, Zefei,Yu, Shanshan,Wu, Qiaqing,Zhu, Dunming
, p. 556 - 561 (2019/01/04)
The morphinan skeleton is an important sub-structure in many medicines such as dextromethorphan, and can be constructed from 1-benzyl-1,2,3,4,5,6,7,8-octahydroisoquinoline (1-benzyl-OHIQ) derivatives. 1-Benzyl-3,4,5,6,7,8-hexahydroisoquinolines (1-benzyl-HHIQs), the precursors of 1-benzyl-OHIQs, constitute a type of bulky α, β-unsaturated imines. Until now, the application of imine reductases (IREDs) to α, β-unsaturated imines has only rarely been reported. In this study, through evaluation of 48 IREDs, both enantiomers of 1-(4-methoxybenzyl)-1,2,3,4,5,6,7,8-octahydroisoquinoline (1-(4-methoxybenzyl)-OHIQ) were obtained in high yield and excellent optical purity. Among the enzymes, the most steric hindrance-tolerant IRED from Sandarearacinus amylolyticus (IR40) was able to convert various phenyl substituted 1-benzyl-HHIQ to the corresponding 1-benzyl-OHIQ derivatives with excellent enantiometric excess. These results provide an effective route to synthesize these important compounds via enantioselective reduction of bulky α, β-unsaturated imine precursors, which can be readily prepared from 2-(1-cyclohexenyl)ethylamine and corresponding aryl acetic acids. (Figure presented.).
A (S) or (R)- 1 - (4 - methoxybenzyl) - 1, 2, 3, 4, 5, 6, 7, 8 - quinoline of eight hydrogens different preparation method
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Paragraph 0064; 0066; 0072; 0074; 0076, (2018/03/01)
The invention discloses a preparation method of (S) or (R)-1-(4-methoxy benzyl)-1,2,3,4,5,6,7,8-octahydro isoquinoline acetate, wherein the method includes the steps: (1) mixing an aromatic solution of a compound having a structure represented by the formula III with acetic acid, to obtain a solution 1; (2) adding a (S)-1-(4-methoxy benzyl)-1,2,3,4,5,6,7,8-octahydro isoquinoline acetate seed crystal or a (R)-1-(4-methoxy benzyl)-1,2,3,4,5,6,7,8-octahydro isoquinoline acetate seed crystal into the solution 1, to obtain a solution 2; and (3) cooling the solution 2 to 0-5 DEG C, crystallizing to obtain (S)-1-(4-methoxy benzyl)-1,2,3,4,5,6,7,8-octahydro isoquinoline acetate or (R)-1-(4-methoxy benzyl)-1,2,3,4,5,6,7,8-octahydro isoquinoline acetate.
