22150-33-0Relevant academic research and scientific papers
Synthesis of scopin acetate and 6,7-didehydrohyoscyamin. Intramolecular phenylsulfenylation of a nonactivated methylene group of ethyl N-demethyl-3-O-(phenylthio)tropine-N-carboxylate
Petrovi?, Goran B.,Sai?i?, Radomir N.,?ekovi?, ?ivorad M.
, p. 3179 - 3186 (2003)
The synthesis of scopin acetate (6b) and 6,7-didehydrohyoscyamine (17) was achieved by using tropine (5) as the starting compound. Formal (phenylthio)-radical transfer to the nonactivated 6-position of ethyl N-demethyl-3-O-(phenylthio)tropine-N-carboxylate (9) by irradiation in the presence of hexabutyldistannane is a key step of this synthetic approach, involving ethyl 6,7-didehydro-N-demethyltropine-N-carboxylate (15) as a synthetic intermediate (Schemes 3 and 5). The reaction of 9 with tributylstannane in the presence of ethyl acrylate, as a radicophilic olefin, involves Michael-type alkylation at C(6) of the tropine skeleton affording ethyl N-demethyl-N-(ethoxycarbonyl)tropine-6-propanoate (18) (Scheme 6).
FLUOROPHENYL SUBSTITUTED MUSCARINIC RECEPTOR LIGANDS WITH SELECTIVITY FOR M3 OVER M2
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Page/Page column 35; 36, (2019/06/23)
The present invention relates to fluorophenyl substituted muscarinic receptor ligands with selectivity for M3 over M2 and to the use of these compounds in the treatment of various diseases such as asthma, chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD) and urinary incontinence.
Functional characterization of recombinant hyoscyamine 6β-hydroxylase from Atropa belladonna
Li, Jing,Van Belkum, Marco J.,Vederas, John C.
experimental part, p. 4356 - 4363 (2012/08/28)
(-)-Hyoscyamine, the enantiomerically pure form of atropine, and its derivative scopolamine are tropane alkaloids that are extensively used in medicine. Hyoscyamine 6β-hydroxylase (H6H, EC 1.14.11.11), a monomeric α-ketoglutarate dependent dioxygenase, converts (-)-hyoscyamine to its 6,7-epoxy derivative, scopolamine, in two sequential steps. In this study, H6H of Atropa belladonna (AbH6H) was cloned, heterologously expressed in Escherichia coli, purified and characterized. The catalytic efficiency of AbH6H, especially for the second oxidation, was found to be low, and this may be one of the reasons why Atropa belladonna produces less scopolamine than other species in the same family. 6,7-Dehydrohyoscyamine, a potential precursor for the last step of epoxidation, was shown not to be an obligatory intermediate in the biosynthesis of scopolamine using purified AbH6H with an in vitro 18O labeling experiment. Moreover, the nitrogen atom in the tropane ring of (-)-hyoscyamine was found to play an important role in substrate recognition.
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.
Synthesis and nicotinic receptor activity of a hydroxylated tropane
Bremner, John B.,Godfrey, Colette A.,Jensen, Anders A.,Smith, Reginald J.
, p. 271 - 273 (2007/10/03)
(±)-3α-Hydroxy homoepibatidine 4 has been synthesized from the alkaloid scopolamine 5 and its properties as a nicotinic agonist assessed. While still binding strongly, the compound showed reduced agonist potency for the α4β2 nAChR compared with the parent compound epibatidine 1. Compound 4 also displayed generally similar binding and selectivity profiles at α4β2, α 2β4, α3β4, and α4β4 nAChR subtypes to those for nicotine.
Parallel modification of tropane alkaloids
Aberle, Nicholas S.,Ganesan,Lambert, John N.,Saubern, Simon,Smith, Reg
, p. 1975 - 1977 (2007/10/03)
Various tropane alkaloids have been prepared by structural modification of the readily available natural product, scopolamine 1. Reaction of isocyanates with 6,7-dehydrotropine 5 provided a number of urethanes 6a-e. Reductive amination of tropinone 7 and subsequent reaction with isocyanates provided ureas 9a-f. Mitsunobu inversion of the C-3 alcohol of tropine 10 afforded the epimeric ester 11.
A Meisenheimer rearrangement approach to bridgehead hydroxylated tropane alkaloid derivatives
Bremner, John B.,Smith, Reginald J.,Tarrant, Gregory J.
, p. 97 - 100 (2007/10/02)
Thermolysis of 3-t-butyldimethylsiloxy-8-methyl-8-azabicyclo[3.2.1]oct-6-ene N-oxide (11) and (12) in butyronitrile gave 3-t-butyldimethylsiloxy-9-methyl-8-oxa-9-azabicyclo[3.2.2]non-6-ene (13) which upon reductive N-O ring cleavage, hydrogenation, oxidation and deprotection yielded the 3-hydroxy analogue 8-methyl-8-azabicyclo[3.2.1]octane-1,3-diol (6a ? 6b) of the tropane alkaloid physoperuvine.
