N-Demthylation Studies of Pavine Alkaloids

Lee, Shoei‐Sheng; Liu, Yi-Chu; Chang, Shu-Hwei; Chen, Chung‐Hsiung

doi:10.3987/com-93-6441

Cited by 4 publications

(5 citation statements)

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“…For example, eschscholtzidine 19a (a pavine alkaloid) was converted to its corresponding cyanamide upon treatment with BrCN in 80% yield. Subsequent hydrolysis of the cyanamide under basic conditions led to noreschscholtzidine 19c in 82% yield [ 34 ]. Fluoxetine 20c , an antidepressant registered in the WHO list of essential medicines, can also be synthesized from 20a following a one-step N -demethylation using the von Braun method [ 35 ] ( Figure 2 ).…”

Section: General Chemical Methods For N -Dealkylat...mentioning

confidence: 99%

N-Dealkylation of Amines

2022

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N-dealkylation, the removal of an N-alkyl group from an amine, is an important chemical transformation which provides routes for the synthesis of a wide range of pharmaceuticals, agrochemicals, bulk and fine chemicals. N-dealkylation of amines is also an important in vivo metabolic pathway in the metabolism of xenobiotics. Identification and synthesis of drug metabolites such as N-dealkylated metabolites are necessary throughout all phases of drug development studies. In this review, different approaches for the N-dealkylation of amines including chemical, catalytic, electrochemical, photochemical and enzymatic methods will be discussed.

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Section: General Chemical Methods For N -Dealkylat...mentioning

confidence: 99%

N-Dealkylation of Amines

2022

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“…A range of other non-opiate alkaloids have also been N-demethylated using the von Braun reaction [15]. One such example is the pavine alkaloid (+)-eschscholtzidine (20a) which was converted to the corresponding N-norcyanamide in 80% yield and subsequently hydrolysed under basic conditions to give (+)-noreschscholtzidine (20b) in 82% yield [22].…”

Section: The Von Braun Reactionmentioning

confidence: 99%

“…All of these chloroformates have been applied to opiates and other tertiary N-methyl amine alkaloids. N-Norcodeine (2b) has been obtained in 43% isolated yield from codeine (2a) employing ethyl chloroformate (22) as the N-demethylating reagent [34]. Using phenyl chloroformate (24), morphine (1a) was N-demethylated to give the expected phenyl carbamate intermediate in 91% yield which was hydrolysed to N-normorphine (1b) in 44% isolated yield [34].…”

Section: The Von Braun Reactionmentioning

confidence: 99%

“…The N-methyl quaternary pavine (-)-caryachine N-metho salt ( 63) is a major alkaloid isolated as the perchorate salt from Cryptocarya chinens. The quaternary nitrogen centre possesses two methyl groups, one of which can be removed using the pungent nucleophile sodium hydrogen telluride NaHTe to give the tertiary amine (-)-caryachine (64) in 73% yield (Figure 21) [22]. Alternatively, treatment in refluxing DMF was shown to accomplish the same transformation in 79% yield.…”

Section: N-demethylation Of Quaternary Ammonium Saltsmentioning

confidence: 99%

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N-Demethylation of Alkaloids

Thavaneswaran

McCamley

Scammells

2006

Natural Product Communications

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The removal of an N-methyl group, or N-demethylation, is a useful chemical transformation in organic synthesis which has particular importance in the field of alkaloid chemistry. Historically, tertiary N-methyl alkaloids have been N-demethylated using the same methods as for N-dealkylating tertiary amines. Such methodologies have included the von Braun reaction, the use of chloroformate and azodicarboxylate reagents and the Polonovski reaction, amongst others. Photochemical and biochemical procedures have also been successfully employed. This review will examine these N-demethylation procedures, with special emphasis on their application to opiate alkaloids.

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“…In synthetic chemistry, two major types of approaches have been extensively examined for the demethylation of amines (Figure B). One is based on reaction of a tertiary amine with cyanogen bromide, followed by the release of bromomethane and a hydrolysis step (von Braun reaction) . The cyanogen bromide may also be replaced by chloroformate esters to achieve similar demethylation process .…”

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confidence: 99%

Copper-Catalyzed Radical N-Demethylation of Amides Using N-Fluorobenzenesulfonimide as an Oxidant

Lei

Liu

et al. 2020

Org. Lett.

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An unprecedented N-demethylation of N-methyl amides has been developed by use of N-fluorobenzenesulfonimide as an oxidant with the aid of a copper catalyst. The conversion of amides to carbinolamines involves successive single-electron transfer, hydrogen-atom transfer, and hydrolysis, and is accompanied by formation of N-(phenylsulfonyl)benzenesulfonamide. Carbinolamines spontaneously decompose to N-demethylated amides and formaldehyde, because of their inherent instability.Letter pubs.acs.org/OrgLett

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N-Demthylation Studies of Pavine Alkaloids

Cited by 4 publications

References 0 publications

N-Dealkylation of Amines

N-Dealkylation of Amines

N-Demethylation of Alkaloids

Copper-Catalyzed Radical N-Demethylation of Amides Using N-Fluorobenzenesulfonimide as an Oxidant

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