- Thiazolyl-benzimidazoles
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The invention is directed to compounds of formula (1) [image] and pharmaceutically acceptable salts thereof, methods for the preparation thereof, and methods of use thereof.
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Page/Page column 42
(2008/06/13)
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- Insights into the mechanism of the site-selective sequential palladium-catalyzed cross-coupling reactions of dibromothiophenes/ dibromothiazoles and arylboronic acids. Synthesis of PPARβ/δ agonists
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A reactivity study, aided by NMR spectroscopy, allowed a mechanistic rationale to be postulated for the palladium-catalyzed regioselective coupling of arylboronic acid (and arylstannane where feasible) at the position next to the sulfur atom in functional
- Pereira, Raquel,Furst, Audrey,Iglesias, Beatriz,Germain, Pierre,Gronemeyer, Hinrich,De Lera, Angel R.
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p. 4514 - 4525
(2008/09/19)
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- Azoles. Part 8. Metallation and Bromine -> Lithium Exchange Reactions of Polyhalogenothiazoles
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2,4-Dichloro- and 2,4-dibromo-thiazole were deprotonated at position-5 with LiN(iPr)2 in THF at -78 deg C and the resulting lithium compound was quenched with various reagents, to yield various trisubstituted thiazoles. 2,5-Dibromo-4-chlorothiazole reacted with n-butyllithium in THF at -78 deg C at position-5 and the resulting lithium derivative gave 2-bromo-4-chloro-5-substituted thiazoles when quenched with the appropriate reagent.Both the 2- and 5-bromine-atoms were reactive in diethyl ether. 2,5-Dibromothiazole failed to deprotonate at position-4 under various reaction conditions, whereas treatment of 2,4,5-tribromothiazole with 1 mole equivalent of n-butyllithium in THF at -90 deg C, followed by addition of dimethyl disulfide after 30 min, gave a high yield of the 2,5-bis(methylthio)-compound.The tribromo-compound was also treated with 1 mole equivalent of n-butyllithium or methyllithium under various reaction conditions and the products formed after hydrolysis were analysed by 1H NMR spectroscopy.The 5-bromine-atom is the most reactive and greater selectivity is obtained with methyllithium.
- Athmani, Salah,Bruce, Andrew,Iddon, Brian
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p. 215 - 219
(2007/10/02)
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