- Copper nanoparticles (CuNPs) catalyzed chemoselective reduction of nitroarenes in aqueous medium
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Abstract: A procedure for practical synthesis of CuNPs from CuSO4·5H2O is established, under appropriate reaction conditions, using rice (Oryza sativa) as an economic source of reducing as well as a stabilizing agent. Optical and microscopic techniques are employed for the characterization of the synthesized CuNPs and the sizes of the particles were found to be in the range of 8 ± 2 nm. The nanoparticles are used as a catalyst for chemoselective reduction of aromatic nitro compounds to corresponding amines under ambient conditions and water as a reaction medium. Graphic abstract: CuNPs are synthesized using hydrolysed rice and used as catalyst for chemoselective reduction of nitroarenes to their corresponding amines in water. [Figure not available: see fulltext.]
- Chand, Dillip Kumar,Rai, Randhir
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- Process for the preparation of unsaturated amino compounds
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The present invention relates to a process for the preparation of aromatic amino compounds which are substituted by a least one group comprising at least one unsaturated carbon-carbon bond, by catalytic hydrogenation of corresponding aromatic nitro compounds in the presence of a modified noble metal catalyst, wherein the noble metal catalyst used is platinum modified with a metal selected from the group consisting of lead, mercury, bismuth, germanium, cadmium, arsenic, antimony, silver and gold, and to novel noble metal catalysts for use in this process.
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- An unexpected Mitsunobu reaction. A direct route to the 2,5-diazabicyclo[2.2.1]heptan-3-one skeleton as a γ-lactam mimic of β-lactam antibiotics
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Treatment of anilides of N-protected (2S,4R)-4-hydroxyproline, e.g. 1, with thioacetic acid under Mitsunobu conditions gives, unexpectedly, 2,5-diazabicyclo[2.2.1]heptan-3-ones, e.g. 2, the products of intramolecular cyclisation. However, the less acidic N-benzylamides of these proline derivatives, e.g. 7, are not sufficiently acidic and the hydrazido anion generated in the Mitsunobu reaction displaces the activated hydroxy group in an intermolecular reaction to give 8. The bicyclic γ-lactams are potential analogues of the β-lactam antibiotics and suitable derivatives 9, 10,11 and 12 are found to be competitive inhibitors of class A and C β-lactamases, with Ki as low as 70 μM.
- Hadfield, Peter S.,Galt, Ron H. B.,Sawyer, Yvonne,Layland, Nicola J.,Page, Michael I.
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p. 503 - 509
(2007/10/03)
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- Antibiotic penem compounds
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The present invention provides a compound of the formula (I) STR1 wherein: R1 is 1-hydroxyethyl, 1-fluoroethyl or hydroxymethyl; R2 is hydrogen or C1-4 alkyl; Z is carboxy, sufonic acid, tetrazol-5-yl or C 1-4 alkylsulfonylcarbamoyl (--CONHSO2 C1-4 alkyl); A is a phenyl or thienyl ring; and A is optionally further substituted by one or two substituents or a pharmaceutically acceptable salt or in vivo hydrolysable ester thereof. Processes for their preparation, intermediates in their preparation, their use as therapeutic agents and pharmaceutical compositions containing them.
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- Antibiotic compounds
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The present invention relates to carbapenems and provides a compound of the formula (I): STR1 or a pharmaceutically acceptable salt or in vivo hydrolysable ester thereof wherein: R1 is 1-hydroxyethyl, 1-fluoroethyl or hydroxymethyl; R2 is hydrogen or C1-4 alkyl; R3 is hydrogen or C1-4 alkyl; R4 and R5 are the same or different and are selected from hydrogen, halo, cyano, C1-4 alkyl, nitro, hydroxy, carboxy, C1-4 alkoxy, C1-4 alkoxycarbonyl, aminosulphonyl, C1-4 alkylaminosulphonyl, di-C1-4 alkylaminosulphonyl, carbamoyl, C1-4 alkylcarbamoyl, di-C1-4 alkylcarbamoyl, trifluoromethyl, sulphonic acid, amino, C1-4 alkylamino, di-C1-4 alkylamino, C1-4 alkanoylamino, C1-4 alkanoyl(N-C1-4 alkyl)amino, C1-4 alkanesulphonamido and C1-4 alkylS(O)n -- wherein n is zero, one or two: with the proviso that there is no hydroxy or carboxy substituent in a position ortho to the --NR2 --. Processes for their preparation, intermediates in their preparation, their use as therapeutic agents and pharmaceutical compositions containing them.
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