- Deprotonative metalation of functionalized aromatics using mixed lithium-cadmium, lithium-indium, and lithium-zinc species
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In situ mixtures of CdCl2TMEDA (0.5 equiv; TMEDA = N,N,N',N'-tetramethylethylenediamine) or InCl3 (0.33 equiv) with [Li(tmp)] (tmp = 2,2,6,6-tetramethylpiperidino; 1.5 or 1.3 equiv, respectively) were compared with the previously described mixture of ZnCl2-TMEDA (0.5 equiv) and [Li(tmp)] (1.5 equiv) for their ability to deprotonate anisole, benzothiazole, and pyrimidine. [(tmp)3CdLi] proved to be the best base when used in tetrahydrofuran at room temperature, as demonstrated by subsequent trapping with iodine. The Cd-Li base then proved suitable for the metalation of a large range of aromatics including benzenes bearing reactive functional groups (CONEt2, CO2Me, CN, COPh) or heavy halogens (Br, I), and heterocycles (from the furan, thiophene, pyrrole, oxazole, thiazole, pyridine, and diazine series). Fivemembered heterocycles benefiting from doubly activated positions were similarly dideprotonated at room temperature. The aromatic lithium cadmates thus obtained were involved in palladium-catalyzed cross-coupling reactions or simply quenched with acid chlorides.
- Snegaroff, Katia,L'Helgoual'ch, Jean-Martial,Bentabed-Ababsa, Ghenia,Nguyen, Tan Tai,Chevallier, Floris,Yonehara, Mitsuhiro,Uchiyama, Masanobu,Derdour, Aicha,Mongin, Florence
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experimental part
p. 10280 - 10290
(2010/04/24)
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- Pyrazole derivatives
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The present invention relates to cis- and trans-forms of pyrazole derivatives, salts thereof, or agents containing the same, and represented by the general formula (I): wherein G represents a nitrogen containing saturated heterocyclic structure represented by the following formula: These compounds exhibit anti-tumor activity on 5-FU-resistant tumors and effects on P glycoprotein expressing, multiple-drug resistant tumors. An example of a pyrazole derivative which demonstrates 50% inhibition of tumor cell growth is 3-[4-(3-chloro-5-fluorophenyl)-1 piperazinyl]-1-[1-(3-chloro-2-pyridyl)-5-methyl-4-pyrazolyl)-1-trans-propene hydrochloride. Synthesis of the compounds represented by formula (I) can be prepared by any one of various routes such as a Mannich reaction, a Wittig reaction, reductive amination or substitution by allylation.
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