- Selectivities in the oxidation of tertiary amines and pyridine derivatives by perfluoro cis-2,3-dialkyloxaziridines
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When tertiary amines 1 are reacted with perfluoro cis-2,3- dialkyloxaziridines 2 at -60 °C corresponding N-oxides 3 are formed in high yields. The process is chemoselective and diastereoselective. The chemoselectivity in the reaction of alkenyl substituted pyridines is solvent dependent, attack occurring exclusively at the carbon-carbon double bond or at the nitrogen atom under protic and aprotic conditions, respectively. Lower selectivities were obtained when standard reagents were used.
- Arnone, Alberto,Metrangolo, Pierangelo,Novo, Barbara,Resnati, Giuseppe
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- New methodology for the N-demethylation of opiate alkaloids
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(Chemical Equation Presented) N-Demethylation is a key step in the preparation of a number of semisynthetic opiate pharmaceuticals. Herein we report a high-yielding, catalytic procedure for the N-demethylation of opiates which has a number of advantages over existing methods. For example, tetrasodium 5,10,15,20-tetra(4-sulfophenyl)-porphyrinatoiron(II) (0.3 molar equiv) effected the transformation of codeine methyl ether to the corresponding N-nor analogue in 91% yield. The catalyst was readily removed and recycled.
- Dong, Zemin,Scammells, Peter J.
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- Preparation method of dextromethorphan hydrobromide oxynitride impurity (by machine translation)
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The invention discloses a preparation method of a compound represented by dextromethorphan hydrobromide impurity type I. The dextromethorphan hydrobromide impurity type I preparation method comprises the following steps: dissolving dextromethorphan hydrobromide in water, carrying out free extraction with a base, extracting, and reacting under the action of an oxidizing agent by using an organic solvent to obtain the compound . the method comprises the following steps: dissolving dextromethorphan hydrobromide in water. The preparation method is convenient to operate, mild and controllable in reaction conditions, high in reaction stability, high in reaction product yield, and high in purity. (by machine translation)
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Paragraph 0031-0044
(2019/08/30)
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