- SELECTIVE MONOMETHYL ESTERIFICATION OF DICARBOXYLIC ACIDS BY USE OF MONOCARBOXYLATE CHEMISORPTION ON ALUMINA.
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The application of alumina as a solid support affords a new procedure for selective reactions. Although it is difficult to obtain monoesters in the esterification of dicarboxylic acids by conventional methods, dicarboxylic acids adsorbed on alumina selectively form the monoesters. Terephthalic acid (1), isophthalic acid, cis- and trans-1,4-cyclohexanedicarboxylic acids, and aliphatic dicarboxylic acids give the corresponding monomethyl esters quantitatively with diazomethane. On the basis of these results, the authors suggest that dicarboxylic acids are adsorbed on alumina through one of their carboxyl groups, and the carboxyl group not adsorbed on the alumina is esterified selectively. Selective monomethyl esterification of phthalic acid is not successful on alumina, probably as a consequence of the close proximity of the two carboxyl groups and the forced orientation of the second group when one is adsorbed.
- Ogawa,Chihara,Taya
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- Structure-activity relationship study of novel NR2B-selective antagonists with arylamides to avoid reactive metabolites formation
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A novel potent NMDA-NR2B selective antagonist (5b) without the reactive metabolites formation issue was identified. Through this study, a close correlation between reactive metabolites formation and calculated HOMO energies of parent compounds was found.
- Kawai, Makoto,Sakurada, Isao,Morita, Asato,Iwamuro, Yuko,Ando, Kazuo,Omura, Hirofumi,Sakakibara, Sachiko,Masuda, Tsutomu,Koike, Hiroki,Honma, Teruki,Hattori, Kazunari,Takashima, Tadayuki,Mizuno, Kunihiko,Mizutani, Mayumi,Kawamura, Mitsuhiro
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p. 5537 - 5542
(2008/03/14)
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- Thiazolidinone compounds and composition for angina pectoris comprising the compounds as an active ingredient
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A thiazolidinone compound represented by general formula (I) or a pharmacoligically acceptable salt thereof, STR1 wherein W represents sulfur or oxygen and X represents --N(R1)--, or alternatively X represents sulfur or oxygen and W represents --N(R1)--, and R1 represents hydrogen, alkyl or substituted alkyl; R2 and R3 are the same or different from each other, and each represents hydrogen, alkyl, substituted alkyl, aryl, or 5- or 6-membered heteroaryl; R4 represents hydrogen, alkyl or substituted C1 -C4 alkyl; R5 represents substituted cycloalkyl which may contain nitrogen, provided the substituents include --B--ONO2 (wherein B represents a single bond or alkylene) as the indispensable member and alkyl groups as optional members; and A represents a single bond or alkylene, has an excellent anti-anginal effect and thus is useful as an angina pectoris remedy or preventive.
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- Separation of cis/trans-cyclohexanecarboxylates by enzymatic hydrolysis: Preference for diequatorial isomers
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4-Substituted cis/trans-cyclohexanecarboxylates have been separated into the isomers by enzymatic hydrolysis with lipase from Candida rugosa with very good selectivity. The enzyme preferentially recognizes diequatorial conformations. Copyright (C) 1996 Elsevier Science Ltd.
- Koenigsberger, Kurt,Luna, Hector,Prasad, Kapa,Repic, Oljan,Blacklock, Thomas J.
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p. 9029 - 9032
(2007/10/03)
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