- Selective hydrolysis of methanesulfonate esters
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The pH dependence of the hydrolysis of 4-{2-[(methylsulfonyl)oxy]ethyI} phenyl methanesulfonate, 1, and two carboxylate esters, ethyl 2(S)-ethoxy-3-(4-hydroxyphenyl)propionate, 2 and (2S)-2-ethoxy-3-[4-(2-{4- [(methylsulfonyl)oxy]phenyl}ethoxy)phenyl]propanoate, 3, has been studied with a view to the selective removal of any remaining 1, following coupling with 2 to generate 3 in water at 95 °C (Scheme 1). It is shown that reduction of pH from that of the reaction conditions (pH ≈ 10) to pH 7-8 has little effect on the hydrolysis of 1, which is dominated by the water rate over this pH range, but reduces the rate of hydrolysis of the carboxylate ester group by 3 orders of magnitude (pH 7). This very strong quantitative difference in the response of the two types of ester group to pH change allows complete removal of 1 at low pH without measurable loss to the product ester, 3. The conclusions should be generally applicable to the removal of potentially genotoxic alkyl esters of methane sulfonic acid in the presence of carboxylic esters and other base-sensitive groups.
- Chan, Lai Chun,Cox, Brian G.,Sinclair, Rhona S.
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- ABC EXPRESSION PROMOTERS
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The ABCA1 mRNA expression-promoting agent, LXRα mRNA expression-promoting agent, ABCG1 mRNA expression-promoting agent, cholesterol efflux-promoting agent, cholesteryl ester accumulation-inhibiting agent, ACAT-1 mRNA expression-inhibiting agent and CEH mRNA expression-promoting agent of the present invention are excellent in the ability to control cholesterol distribution in the body and have low toxicity.
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- NEW PROCESS
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A process for the preparation of a compound of formula (I); in which R represents H or an acid protecting group which comprises reacting a compound of formula (II); in which R is as previously defined with a compound of formula (III); wherein X is a suitable leaving group in the presence of a base and using water as a diluent.
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Page/Page column 6
(2008/06/13)
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- 3-aryl-2-hydroxypropionic acid derivative (I)
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A novel 3-aryl-2-hydroxypropionic acid derivative, a process and intermediate for its manufacture, pharmaceutical preparations containing it and the use of the compound in clinical conditions associated with insulin resistance.
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