65849-33-4Relevant academic research and scientific papers
Dual aromatase-steroid sulfatase inhibitors
Woo, L. W. Lawrence,Bubert, Christian,Sutcliffe, Oliver-B.,Smith, Andrew,Chander, Surinder K.,Mahon, Mary F.,Purohit, Atul,Reed, Michael J.,Potter, Barry V. L.
, p. 3540 - 3560 (2008/02/09)
By introducting the steroid sulfatase inhibitory pharmacophore into aromatase inhibitor 1 (YM511), two series of single agent dual aromatase-sulfatase inhibitors (DASIs) were generated. The best DASIs in'vitro (JEG-3 cells) are 5, (IC50(aromatase) = 0.82 nM; IC 50(sulfatase) = 39 nM), and 14, (IC50(aromatase) = 0.77 nM; IC50(sulfatase) = 590 nM). X-ray crystallography of 5, and docking studies of selected compounds into an aromatase homology model and the steroid sulfatase crystal structure are presented. Both 5 and 14 inhibit aromatase and sulfatase in PMSG pretreated adult female Wistar rats potently 3 h after a single oral 10 mg/kg dose. Almost complete dual inhibition is observed for 5 but the levels were reduced to 85% (aromatase) and 72% (sulfatase) after 24 h. DASI 5 did not inhibit aldosterone synthesis. The development of a potent and selective DASI should allow the therapeutic potential of dual aromatase-sulfatase inhibition in hormone-dependent breast cancer to be assessed.
Bu3SnH mediated oxidative radical cyclisations: Synthesis of 6H-benzo[c]chromen-6-ones
Bowman, Russell,Mann, Emma,Parr, Jonathan
, p. 2991 - 2999 (2007/10/03)
Attempts to synthesise 6H-benzo[c]chromen-6-ones by Bu3SnH mediated cyclisation of o-(benzoyl)aryl radicals failed because of the preferred trans conformation of the ester. This problem was overcome by using cyclisation of o-(benzyloxy)aryl and o-[(aryloxy)methyl]aryl radicals to yield 6H-benzo[c]chromenes followed by oxidation to the 6H-benzo[c]chromen-6-ones. 3-Methoxy-6H-benzo[c]chromen-6-one 1, one of the main biologically active constituents of shilajit, a herbal medicine used in countries surrounding the Himalayan mountains, was synthesised using Bu3SnH mediated cyclisation of 1-benzyloxy-2,4-dibromo-5-methoxybenzene 31 to yield 3-methoxy-6H-benzo[c]chromene 25 followed by PCC oxidation of the 6-position. In order to avoid the problems of rearrangement, the aryl radical cyclisation must be designed such that whichever way the spirodienyl intermediate rearranges, the same product is obtained. For instance, the Bu3SnH mediated cyclisation of 1-iodo- and 1-bromo-2-(3-methoxy-phenyloxymethyl)benzenes 22 and 23 respectively gave both the isomers, 1-methoxy-6H-benzo[c]chromenes 24 and 3-methoxy-6H-benzo[c]chromenes 25 via rearrangement of the intermediate spirodienyl radical. The synthesised 6H-benzo[c]chromenes were oxidised in high yield to the corresponding 6H-benzo[c]chromen-6-ones. The mechanism of the 'oxidative' Bu3SnH mediated cyclisation is discussed.
Carbanionically Induced -Migrations of ?- and Coordinatively Unsaturated Groups
Hellwinkel, Dieter,Laemmerzahl, Frank,Hofmann, Gunter
, p. 3375 - 3405 (2007/10/02)
According to a general reaction scheme, o-lithioaryl esters 4a,b, amides 13a,b 17b, and amidines 39b of non-enolizable carboxylic acids as well as a corresponding diphenylphosphinic amide 51b react under mild conditions to give the intensely coloured lithium derivatives of o-acylphenoles 6a,b and o-acylarenamines 15a,b, 18a, 41a, 52a, which are finally hydrolyzed to the neutral products 7a,b, 14a,b, 18b, 41b, 52b, respectively.The lithiated precursors of the rearrangement are mostly prepared by halogen/metal exchange reactions.In the case of N,N-di-p-tolylpivalamide 33 such a -rearrangement also could be induced by direct metalation of the educt.With N-methyl-N-phenylpivalamide (29), however, exclusive metalation of the N-methyl group occurs, followed by -migration of the pivaloyl group.Silyl groups, too, can undergo analogous -shifts, as was demonstrated by the rearrangement of the o-lithiated N-(trimethylsilyl)aniline 63b to the o-(trimethylsilyl)anilines 65a,b.When a benzoyl and sulfonyl group can compete for the -shifts, as in the N-tosylated benzamide 47b, only the benzoyl group migrates.However, the migration tendency of the trimethylsilyl group equals that of the benzoyl group as was shown with the N-silylated benzamide 66b.
