16839-98-8Relevant articles and documents
Photochemical N-demethylation of alkaloids
Ripper, Justin A.,Tiekink, Edward R.T.,Scammells, Peter J.
, p. 443 - 445 (2001)
Certain alkaloids were observed to undergo N-demethylation processes under photochemical conditions. Tropine, acetyltropine, tropinone, and atropine were cleanly N-demethylated upon treatment with tetraphenylporphin, oxygen, and light. Dextromethorphan also underwent a N-demethylation reaction, but reacted further to afford an imine. In contrast, 14-acyloxycodeinones underwent a photochemically induced tandem N-demethylation-acyl migration.
MEANS AND METHODS FOR THE N-DEALKYLATION OF AMINES
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Page/Page column 21, (2017/11/10)
The invention relates to improved means and methods for N- dealkylation of alkylated amines. Provided is a method for the catalytic N- dealkylation of an N-alkylated amine substrate, comprising incubating said amine substrate in a suitable solvent in the
Utility of iron nanoparticles and a solution-phase iron species for the: N-demethylation of alkaloids
Awalt, Jon Kyle,Lam, Raymond,Kellam, Barrie,Graham, Bim,Scammells, Peter J.,Singer, Robert D.
, p. 2587 - 2594 (2017/07/17)
The N-demethylation of selected N-methylalkaloids using a modified Polonovski reaction can be accomplished using a novel green methodology employing nanoscale zero-valent iron, nZVI, in isopropanol. Use of nZVI promotes a much faster conversion to N-demethylated products due to much higher surface area on the metal surface as shown by SEM analysis. Rates of conversion can be further enhanced using catalytic quantities of the solubilised iron(0) species triiron dodecacarbonyl, Fe3(CO)12.
Studies on the oxidative N-demethylation of atropine, thebaine and oxycodone using a FeIII-TAML catalyst
Do Pham, Duy D.,Kelso, Geoffrey F.,Yang, Yuanzhong,Hearn, Milton T.W.
, p. 1399 - 1409 (2014/03/21)
The reaction pathway and selectivity of the oxidative N-demethylation of the alkaloid atropine with H2O2 using a Fe III-TAML catalyst has been investigated. The conversion of atropine in ethanol with aqueous H2O
N-Demethylation of N-methyl alkaloids with ferrocene
Kok, Gaik B.,Scammells, Peter J.
supporting information; experimental part, p. 4499 - 4502 (2010/09/15)
Under Polonovski-type conditions, ferrocene has been found to be a convenient and efficient catalyst for the N-demethylation of a number of N-methyl alkaloids such as opiates and tropanes. By judicious choice of solvent, good yields have been obtained for dextromethorphan, codeine methyl ether, and thebaine. The current methodology is also successful for the N-demethylation of morphine, oripavine, and tropane alkaloids, producing the corresponding N-nor compounds in reasonable yields. Key pharmaceutical intermediates such oxycodone and oxymorphone are also readily N-demethylated using this approach.
Synthesis and radiolabelling of ipratropium and tiotropium for use as PET ligands in the study of inhaled drug deposition
Issa, Fatiah,Kassiou, Michael,Chan, Hak-Kim,McLeod, Malcolm D.
, p. 53 - 58 (2007/10/03)
Ipratropium bromide [(1R,3r,5S,8r,2′RS)-3-(3′-hydroxy-2′- phenylpropionyloxy)-8-isopropyl-8-methyl-8-aza-bicyclo[3.2.1]octan-8-ium bromide] and tiotropium bromide [(1R,2R,4S,5S,7s)-7-[2′-hydroxy-2′, 2′-di(thiophen2″-yl)acetoxy]-9,9-dimethyl-9-aza-3-oxatricyclo[3.3.1. 02,4]nonan-9-ium bromide] are inhaled drugs used in the treatment of chronic obstructive pulmonary disease (COPD) and asthma. Tertiary amine precursors have been synthesized and radiolabelled with carbon-11 by N-alkylation with [11C]CH3I. The [11C] ipratropium and [11C]tiotropium positron emission tomography (PET) ligands are obtained with high radiochemical purity, in 0.3 and 0.5% non-decay corrected yields based on [11C]CO2 at end-of-synthesis and specific activities of 11 and 18 GBq μ mol-1, respectively, calculated at end-of-synthesis. These PET radioligands can be used in the study of inhaled drug deposition. CSIRO 2006.
Further investigation of the N-demethylation of tertiary amine alkaloids using the non-classical Polonovski reaction
Thavaneswaran, Shanti,Scammells, Peter J.
, p. 2868 - 2871 (2007/10/03)
The iron salt-mediated Polonovski reaction efficiently N-demethylates certain opiate alkaloids. In this process, the use of the hydrochloride salt of the tertiary N-methyl amine oxide was reported to give better yields of the desired N-demethylated product. Herein, we report further investigation into the use of N-oxide salts in the iron salt-mediated Polonovski reaction. An efficient approach for the removal of iron salts that greatly facilitates isolation and purification of the N-nor product is also described.
Presynaptic cholinergic modulators as potent cognition enhancers and analgesic drugs. 1. Tropic and 2-phenylpropionic acid esters
Gualtieri,Conti,Dei,Giovannoni,Nannucci,Romanelli,Scapecchi,Teodori,Fanfani,Ghelardini,Giotti,Bartolini
, p. 1704 - 1711 (2007/10/02)
Previous studies have shown that (R)-(+)-hyoscyamine has analgesic activity as a consequence of increased ACh release following antagonism of central muscarinic autoreceptors. Since the enhancement of central cholinergic transmission could be beneficial for cognitive disorders, we manipulated (R)-(+)-hyoscyamine, synthesizing several derivatives of tropic and 2-phenylpropionic acids, with the aim of obtaining drugs which are able to increase ACh release and consequently to show analgesic and nootropic activities. The results showed that several new compounds are indeed potent analgesics (with an analgesic efficacy comparable to that of morphine) and that the most potent one ((±)-19, PG9) also has remarkable cognition- enhancing properties. Our study confirmed that the mechanism of action involves ACh release even if it is still unclear whether only muscarinic autoreceptors or, also, heteroreceptors are involved.
ELECTRON-TRANSFER ACTIVATION. SALT EFFECTS ON THE PHOTOOXADIDATION OF TERTIARY AMINES : A USEFUL N-DEMETHYLATION METHOD
Santamaria, J.,Ouchabane, R.,Rigaudy, J.
, p. 3977 - 3980 (2007/10/02)
Photooxidation of tertiary methylamines sensitized by electron acceptors like 9,10-dicyanoanthracene is shown to proceed by two distinct ways depending on the presence of added salts.In the absence of added salt both nor and N-formyl compounds were obtained while with added salt the nor-derivative is obtained highly efficiently.
ELECTRON-TRANSFER ACTIVATION. PHOTOCHEMICAL N-DEMETHYLATION OF TERTIARY AMINES
Santamaria, J.,Ouchabane, R.,Rigaudy, J.
, p. 2927 - 2928 (2007/10/02)
DAP(2+) sensitized photooxidation of some biologically active N-methylated alkaloids affords the corresponding secondary amines in excellent yields (80-95percent).
