193146-85-9Relevant articles and documents
A Nivalin industrial preparation method (by machine translation)
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Paragraph 0043; 0044, (2019/02/27)
The invention relates to a technical field of drug synthesis, in particular relates to a preparation method of the galanthamine hydrobromide. Preparation method of this invention comprises the following steps: (1) the racemate narwedine as raw materials, adding resolution solvent to get levorotation narwedine; (2) L narwedine [...] butyl boron lithium hydride reduction shall be galantamine free alkali, further and hydrobromic acid shall be galanthamine hydrobromide. (by machine translation)
Stereoselective syntheses of galanthamine and its stereoisomers by complementary Luche and L-selectride reductions
Trinadhachari, Ganala Naga,Kamat, Anand Gopalkrishna,Raghu Babu, Korupolu,Sanasi, Paul Douglas,Prabahar, Koilpillai Joseph
, p. 117 - 124 (2014/02/14)
A diastereodivergent approach for the stereoselective syntheses of all four stereoisomers of galanthamine, (-)-galanthamine 1, (+)-galanthamine 2, (-)-epigalanthamine 3, and (+)-epigalanthamine 4, from (±)-narwedine 5 is reported. Thus (±)-narwedine 5 was resolved by dynamic kinetic resolution to obtain enantiomerically pure (-)-narwedine 6 and (+)-narwedine 7. Each enantiomerically pure isomer of narwedine was subjected to Luche and L-selectride reactions to obtain all four isomers of galanthamine. In these reactions, the (-)-galanthamine 1 and (+)-galanthamine 2 isomers were obtained with an enantiomeric purity of >99.5%, whereas (-)-epigalanthamine 3 and (+)-epigalanthamine 4 are obtained with a chiral purity of >97%. The axial hydride attack by the Luche reduction and the equatorial hydride attack by the L-selectride reduction on the cyclic enone system are explored in the stereoselective synthesis of the galanthamine isomers and thus it was demonstrated that the stereoselective synthesis involving the Luche and L-selectride reductions are complementary in yielding enantiomeric stereogenic centers from a prochiral carbonyl group on the cyclic enone system.
Syntheses and Preparations of Narwedine and Related Novel Compounds
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Page/Page column 4; 12, (2009/01/20)
The present invention relates to a process for preparing racemic narwedine (which can be can be kinetically resolved) to yield (?)-narwedine and which is the biogenic precursor of (?)-galanthamine) and the use thereof as a starting material for producing (?)-galanthamine. The invention further includes processes for preparing (?)-galanthamine and (?)-galanthamine hydrobromide, as well as related novel compounds.