- Synthesis and antiprotozoal activity of some 2-(trifluoromethyl)-1H- benzimidazole bioisosteres
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A series of 2-(trifluoromethyl)-1H-benzimidazole derivatives with various 5- and 6-position bioisosteric substituents (-Cl, -F, -CF3, -CN), namely 1-7, were prepared using a short synthetic route. Each analogue was tested in vitro against the protozoa Giardia intestinalis and Trichomonas vaginalis in comparison with albendazole and metronidazole. Several analogues had IC50 values 1 μM against both species, which make them significantly more potent than either standard. Compound 4 [2,5(6)- bis(trifluoromethyl)-1H-benzimidazole], was 14 times more active than albendazole against T.:vaginalis. This compound (4) also showed moderate antimalarial activity against W2 and D6 strains of Plasmodium falciparum (5.98 and 6.12 μM, respectively). Studying further structure activity relationships through the use of bioisosteric substitution in these benzimidazolic derivatives should provide new leads against protozoal and possibly malarial diseases.
- Navarrete-Vazquez, Gabriel,Rojano-Vilchis, Maria De Monserrat,Yepez-Mulia, Lilian,Melendez, Victor,Gerena, Lucia,Hernandez-Campos, Alicia,Castillo, Rafael,Hernandez-Luis, Francisco
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p. 135 - 141
(2007/10/03)
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- A convenient copper-catalyzed direct animation of nitroarenes with 9-alkylhydroxylamines
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O-Alkylhydroxylamines, particularly O-methylhydroxylamine, aminate nitroarenes in the presence of a strong base and a copper catalyst to give aminonitroarenes in good yields, ortho- or para-Animation with respect to the nitro group takes place, and in some cases the ortho-aminated product is preferentially obtained. With 3-substituted nitrobenzenes where the substituent has a lone pair of electrons, preferential amination occurs at the 2-position to give the sterically most congested 3c-f, 14 and 22g.
- Seko, Shinzo,Miyake, Kunihito,Kavvamura, Norio
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p. 1437 - 1444
(2007/10/03)
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- Nitroarylamines via the Vicarious Nucleophilic Substitution of Hydrogen: Amination, Alkylamination, and Arylamination of Nitroarenes with Sulfenamides
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A new reaction of sulfenamides with electrophilic arenes under basic conditions is described. The σ adducts formed from nitroarenes and the anions of sulfenamides undergo elimination of thiol to produce the corresponding o- and/or p-nitroanilines. This reaction is analogous to the known alkylation and hydroxylation of nitroarenes via the vicarious nucleophilic substitution of hydrogen (VNS). The reaction gives access to a wide range of substituted nitroanilines, nitronaphthylamines, and aminoheterocycles. By means of the reaction with N-alkyl- and N-arylsulfenamides, it is possible to obtain N-alkylnitroanilines and nitrodiarylamines. By varying the structure of sulfenamide and the reaction conditions, particularly the nature and concentration of the base, it is possible to control the orientation of animation.
- Makosza, Mieczyslaw,Bialecki, Maciej
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p. 4878 - 4888
(2007/10/03)
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- Benzimidazolinone derivatives
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Benzimidazolinone derivatives of the general formula (I): STR1 wherein R1, R2 and R3, which may be the same or different, each is a hydrogen or halogen atom or a lower alkyl, halo-lower alkyl, hydroxy-lower alkyl, hydroxyl, lower alkoxy, aryloxy, acyl, cyano, carboxyl, a lower alkoxycarbonyl, carbamoyl, nitro or nitrogen-containing 5- or 6-membered heterocyclic group; A is an ethylene group which may optionally have at least one branch; R4 and R5, which may be the same or different, each is a lower alkyl group or R4 and R5, together with the adjacent nitrogen atom, represent a pyrrolidinyl, piperidino or a morpholino group provided that when STR2 is a piperidino or diethylamino group, at least one of R1, R2 and R3 is other than a hydrogen atom, or pharmaceutically acceptable salts thereof, methods of producing the same and pharmaceutical compositions containing the same are disclosed. Pharmacologically, the above compounds (I) have pulmonary surfactant secretion promoting activity.
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