62346-87-6Relevant articles and documents
Oxidation of alkylarenes by nitrate catalyzed by polyoxophosphomolybdates: Synthetic applications and mechanistic insights
Khenkin, Alexander M.,Neumann, Ronny
, p. 6356 - 6362 (2007/10/03)
Alkylarenes were catalytically and selectively oxidized to the corresponding benzylic acetates and carbonyl products by nitrate salts in acetic acid in the presence of Keggin type molybdenum-based heteropolyacids, H3+xPVxMo12-xO40 (x = 0-2). H 5PV2Mo10O40 was especially effective. For methylarenes there was no over-oxidation to the carboxylic acid contrary to what was observed for nitric acid as oxidant. The conversion to the aldehyde/ketone could be increased by the addition of water to the reaction mixture. As evidenced by IR and 15N NMR spectroscopy, initially the nitrate salt reacted with H5PV2Mo10O 40 to yield a NVO2+[H 4PV2Mo10O40] intermediate. In an electron-transfer reaction, the proposed NVO2 +[H4PV2Mo10O40] complex reacts with the alkylarene substrate to yield a radical-cation-based donor-acceptor intermediate, NIVO2[H4PV 2Mo10O40]-ArCH2R+.. Concurrent proton transfer yields an alkylarene radical, ArCHR., and NO2. Alternatively, it is possible that the NVO 2+[H4PV2Mo10O 40] complex abstracts a hydrogen atom from alkylarene substrate to directly yield ArCHR. and NO2. The electron transfer-proton transfer and hydrogen abstraction scenarios are supported by the correlation of the reaction rate with the ionization potential and the bond dissociation energy at the benzylic positions of the alkylarene, respectively, the high kinetic isotope effect determined for substrates deuterated at the benzylic position, and the reaction order in the catalyst. Product selectivity in the oxidation of phenylcyclopropane tends to support the electron transfer-proton transfer pathway. The ArCHR. and NO2 radical species undergo heterocoupling to yield a benzylic nitrite, which undergoes hydrolysis or acetolysis and subsequent reactions to yield benzylic acetates and corresponding aldehydes or ketones as final products.
Benzimidazole compounds as bradykinin antagonists
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, (2008/06/13)
PCT No. PCT/JP95/01478 Sec. 371 Date Feb. 3, 1997 Sec. 102(e) Date Feb. 3, 1997 PCT Filed Jul. 25, 1995 PCT Pub. No. WO96/04251 PCT Pub. Date Feb. 15, 1996This invention relates to a heterocyclic compound of the formula: wherein a group of the formula: is a group of the formula: etc., X is O, S or N-R5, R1 is lower alkyl, etc., R5 is hydrogen, lower alkyl, etc., R2 is hydrogen, halogen, lower alkyl, etc., R3 is halogen, lower alkyl, etc., R4 is amino optionally having suitable substituent(s), and A is lower alkylene, and a salt thereof, to processes for preparation thereof, and to a pharmaceutical composition comprising the same for the prevention and/or the treatment of bradykinin or its analogues mediated diseases in human being or animals.