- Synthesis, redox properties and antibacterial activity of hindered phenols linked to heterocycles
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A series of benzotriazole, cyclic amides and pyrimidine derivatives, containing 2,6-di-tert-butyl-phenol fragments, were synthesized. The redox properties of obtained compounds were studied using the cyclic voltammetry on a platinum electrode in acetonitrile. The oxidation potentials of all substances were comparable to those of BHT. The obtained compounds were tested for their antibacterial activity, and N-(2-(3,5-di-tert-butyl-4-hydroxyphenyl)-2-oxoethyl)isatin (32 μg/mL) exerted good activity against Staphylococcus aureus.
- Ivanova, Ludmila V.,Koshelev, Vladimir N.,Primerova, Olga V.,Vorobyev, Stepan V.
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- Mechanism of photosolvolytic rearrangement of p-hydroxyphenacyl esters: Evidence for excited-state intramolecular proton transfer as the primary photochemical step
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The photosolvolytic rearrangement of a variety of p-hydroxyphenacyl esters and related compounds 7-16 has been studied in solutions with up to 50% aqueous content, using product studies, triplet quenchers, and nanosecond laser flash photolysis. The p-hydroxyphenacyl moiety has recently been proposed as a new and efficient photoactivated protecting group in aqueous solution. Practical applications have been demonstrated, but much less is known about the mechanism of photoreaction. Our data support a novel mechanism in which the primary photochemical step from the singlet excited state is formal intramolecular proton transfer from the phenolic proton to the carbonyl oxygen of the distal ketone, mediated by solvent water, to generate the corresponding p-quinone methide phototautomer. This reactive intermediate (most likely in its excited state) subsequently expels the carboxylic acid with concerted rearrangement to a spiroketone intermediate, which subsequently leads to the final observed product, p- hydroxyphenylacetic acid. An alternative mechanism is deprotonation of the phenolic proton, loss of the carboxylate, and rearrangement to the spiroketone, all in one concerted primary photochemical step from S1.
- Zhang, Kai,Corrie, John E. T.,Munasinghe, V. Ranjit N.,Wan, Peter
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p. 5625 - 5632
(2007/10/03)
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- Synthesis and biological activities of new heterocyclic aromatic retinoids
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A series of 3-aryl-2H-1-benzopyrancarboxylic acid derivatives was synthesized and evaluated as Retinoic Acid Receptor (RAR) agonists. By modifications of the 3-aryl group, we have obtained new retinoids exhibiting potent cellular differentiating activities and high affinities for RARs. Moreover, hydrogenation of the 2H-1-benzopyran ring led to the 3-(5,6,7,8-tetrahydro-5,5,8,8,-tetramethyl -naphthalen-2-yl)-3,4-dihydro-2H-1-benzopyran-7-yl carboxylic acid, characterized by a RARβ binding profile.
- Diaz,Michel,Stella,Charpentier
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p. 2289 - 2294
(2007/10/03)
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- Pharmaceutically active bicyclic-heterocyclic amines
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The pharmaceutically active bicyclic heterocyclic amines (XXX) STR1 where W1 is --N= or --CH=; W3 is --N= or --CH=; W5 is --N= or --CR5 -- with the proviso that W5 is --CR5 -- when both W1 and W3 are --N= which are useful as pharmaceuticals in treating mild and/or moderate to severe head injury, subarachnoid hemorrhage and subsequent ischemic stroke, asthma and reduction of mucous formation/secretion in the lung and other diseases and injuries.
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- Imidazo- and triazolothiadiazines
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Novel imidazo- and triazolothiadiazines of the general formula I STR1 in which R1 =C1 -C4 -alkyl, R2 =H or C1 -C3 -alkyl and the structural element --A--B--=--CH2 --CH2 --, --CH CH--, --CH=N--, --CH2 --CO-- or --CO--CH2 --, and the physiologically aceptable acid-addition salts thereof, are prepared by reacting 2-halo-1-phenylalkanones of the formula II STR2 (meaning of R1 and R2 as in formula I, X=halogen) with compounds of the formula III STR3 (meaning of --A--B-- as in formula I) and, if appropriate, converting the compounds of the formula I formed into the physiologically acceptable acid-addition salts thereof by means of suitable acids. The compounds of the formula I and the physiologically acceptable acid-addition salts thereof are principally suitable for the prevention and treatment of inflammatory--in particular inflammatory rheumatic--disorders. Some of the intermediates formed during the preparation of the compounds of the formula I are also novel, namely 1-amino-2-mercaptoimidazole STR4 and 1-amino-2-thioxo-5-imidazolidinone STR5
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- 5-(3-alkyl-5-tert.butyl-4-hydroxyphenyl)-2-amino-6H-1,3,4-thiadiazines
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Novel 5-(3-alkyl-5-tert.butyl-4-hydroxyphenyl)-2-amino-6H-1,3,4-thiadiazines of the general formula I STR1 in which R1 =C1 -C4 -alkyl, R2 =H or C1 -C3 -alkyl R3 and R4 =independently of one another, optionally substituted and optionally O- or S-interrupted alkyl, alkenyl or alkynyl groups, it being possible for one of the two radicals to also be H, or R3 +R4 together with the nitrogen atom to which they are bound, may denote an optionally substituted 4- to 7-membered ring which optionally contains a further heteroatom (O, S or N), and the physiologically acceptable acid-addition salts thereof. The compounds are primarily suitable for prevention and treatment of inflammatory--in particular inflammatory rheumatic--disorders and/or pain.
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- Substituted 3-phenyl-7H-thiazol[3,2-b][1,2,4]-triazin-7-ones
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Novel substituted 3-phenyl-7H-thiazolo[3,2-b][1,2,4]-triazin-7-ones of the formula I are disclosed STR1 in which R1, R2 and R3 have the meaning recited in the specification. The compounds are suitable for prevention and treatment of inflammatory disorders.
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