296237-49-5Relevant academic research and scientific papers
METHOD FOR THE PRODUCTION OF HIGH-PURITY 4A, 5, 9, 10, 11, 12,-HEXAHYDRO-6H-BENZOFURO [3A, 3, 2-EF] [2] BENZAZEPINE, AND THE DERIVATIVES THEREOF
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Page/Page column 2, (2010/05/13)
A process for the production of extremely pure galanthamine or extremely pure galanthamine derivatives, whereby a start is made from racemic bromine narwedine, which is debrominated under palladium catalysis. The working-up of the reaction mixture, which is carried out in the presence of oxygen or peroxides, is essential to the process, so that the palladium catalyst is converted into an insoluble form, a form that can be easily separated. The further reaction is carried out by reduction of enantiomerically pure narwedine to form enantiomerically pure galanthamine, whereby it is then alkylated or dealkylated, so that a corresponding substitution on the ring-nitrogen atom is achieved. By further purification, such as recrystallization, residual portions of palladium of below 5 ppm are achieved, so that the direct use as a pharmaceutical raw material is made possible.
Syntheses and Preparations of Narwedine and Related Novel Compounds
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Page/Page column 11, (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.
Processes for the preparation of derivatives of 4a, 5, 9, 10, 11, 12-hexahydro-6H-benzofuro-[3a, 3, 2-ef][2]benzazepine
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Example 29, (2008/06/13)
The invention relates to processes for the preparation of 4a,5,9,10,11,12-hexahydro-6H-benzofuro[3a,3,2-ef][2]benzazepine, or derivatives thereof. Furthermore, the invention also relates to the compounds formed during the preparation of 4a, 5,9,10,11,12-hexahydro-6H-benzofuro[3a,3,2-ef][2]benzazepine.
New achievements in the field of intramolecular phenolic coupling reactions, using hypervalent (III) iodine reagent: Synthesis of galanthamine
Krikorian, Dikran,Tarpanov, Vclichko,Parushev, Stoyan,Mechkarova, Pepa
, p. 2833 - 2846 (2007/10/03)
Our investigations on the Oxidative possibilities of the hypervalent iodine(III) reagent established that phenyliodine(III)bis(trifluoroacctate (PIFA) can provide one-pot contiguous coupling-cyclization reaction giving a product with narwedine skeleton, when used in a phenolic coupling reaction of p'-bromonorbelladine derivatives. A suitably selected precursor gave up to 60% yield of the coupled product.
Processes for the preparation of derivatives of 4a,5,9,10,11,12-hexahydro-6H-benzofuro-[3a,3,2-ef][2]benzazepine
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, (2008/06/13)
The invention relates to processes for the preparation of 4a,5,9,10,11,12-hexahydro-6H-benzofuro(3a,3,2-ef)(2)benzazepine, or derivatives thereof. Furthermore, the invention also relates to the compounds formed during the preparation of 4a,5,9,10,11,12-hexahydro-6H-benzofuro(3a,3,2-ef)(2)benzazepine.
New kilogram-synthesis of the anti-Alzheimer drug (-)-galanthamine
Czollner, Laszlo,Frantsits, Werner,Kueenburg, Bernhard,Hedenig, Ursula,Froehlich, Johannes,Jordis, Ulrich
, p. 2087 - 2088 (2007/10/03)
A concise, scalable synthesis of (-)-galanthamine, a drug being used for the treatment of Alzheimer's disease, is described. The yield of the critical phenolic coupling step was optimized to 45-50%. For the reduction of the aryl bromide, air-activated LiAlH4 was used and racemic narwedine was converted to (-)-narwedine by a second order asymmetric transformation.
A concise, scaleable synthesis of narwedine
Chaplin, David A.,Fraser, Neil,Tiffin, Peter D.
, p. 7931 - 7932 (2007/10/03)
A concise, scaleable synthesis of narwedine from 3,4- dimethoxybenzaldehyde is described. The procedure features a simple modification to the Barton phenolic coupling route.
