- Selective α-Methylation of Ketones
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The convenient and scalable preparative approach for the two-step α-methylation of ketones is described. The optimized protocols for regioselective preparation of enaminones with further diastereoselective and functional groups tolerant hydrogenation to α-methylketones are developed. The scope and limitations of the proposed methodology are discussed. The advantages compared to known procedures are demonstrated. The unexpected role of acetone in the hydrogenation is suggested. The evaluation of the method for both early building block synthesis and late-stage CH-functionalization is shown. The elaborate procedures' preparability and scalability are demonstrated by the synthesis of several α-methyl ketones up to 100 g amount.
- Frolov, Andriy I.,Ostapchuk, Eugeniy N.,Pashenko, Alexander E.,Chuchvera, Yaroslav O.,Rusanov, Eduard B.,Volochnyuk, Dmitriy M.,Ryabukhin, Sergey V.
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p. 7333 - 7346
(2021/06/28)
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- TETRAHYDRONAPHTHYRIDINES AND AZA DERIVATIVES THEREOF AS HISTAMINE H3 RECEPTOR ANTAGONISTS
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The invention relates to compounds of formula (I), wherein X1a, X1 to X5, Ra, Rb, n and R have the meaning as cited in the description and the claims. Said compounds are useful as Histamine H3 receptor antagonists. The invention also relates to pharmaceutical compositions, the preparation of such compounds as well as the production and use as medicament.
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Page/Page column 92-93
(2009/10/30)
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