35998-96-0Relevant academic research and scientific papers
Backbone-Rigidified Oligo(m-phenylene ethynylenes)
Yang, Xiaowu,Yuan, Lihua,Yamato, Kazuhiro,Brown, Amy L.,Feng, Wen,Furukawa, Mako,Zeng, Xiao Cheng,Gong, Bing
, p. 3148 - 3162 (2007/10/03)
Oligo(m-phenylene ethynylenes) (oligo(m-PE)) with backbones rigidified by intramolecular hydrogen bonds were found to fold into well-defined conformations. The localized intramolecular hydrogen bond involves a donor and an acceptor from two adjacent benze
Cobalt(II) chloride-catalyzed chemoselective sodium borohydride reduction of azides in water
Fringuelli, Francesco,Pizzo, Ferdinando,Vaccaro, Luigi
, p. 646 - 650 (2007/10/03)
Reduction of azides to amines and amides was carried out with NaBH4/CoCl2·6H2O in sole water at 25 °C under catalytic heterogeneous conditions. A broad spectrum of azides was reduced in a short time, chemoselectively in high yield and purity.
Nucleophilic reaction upon electron-deficient pyridone derivatives. XIII. Regioselective synthesis of 2-substituted 3-nitropyridines by one-pot reaction of either 4- or 6-substituted 1-methyl-3,5-dinitro-2-pyridones with ketones and ammonia
Tohda,Kawahara,Eiraku,Tani,Nisiwaki,Ariga
, p. 2176 - 2186 (2007/10/02)
A one-pot synthesis of 2-substituted 3- nitropyridines was developed by a ring transformation of 6- or 4-substituted 1-methyl-3,5-dinitro-2-pyridones (2 or 3) with ammonia and enamines derived from ketones. Some intermediates having a 2,6-diazabicyclo[3.3.1]nonane skeleton were isolated from reactions of 3. The ring transformation proceeds via an addition-addition-elimination-elimination mechanism. Few competitive isomeric by-products, 4-substituted 3-nitropyridines and 4-nitroanilines, were formed. All the 2 substrates showed good reactivity, but the 3 substrates having electron-withdrawing substituents were less reactive and selective. 1,4,6-Trimethyl-3,5-dinitro-2-pyridone did not give any products. The selectivity is interpreted in terms of differences of thermodynamic (main selection rule B) and kinetic stability (minor selection rule A) between the possible bicyclic intermediates which are expected to be formed via the mechanism.
REGIOSELECTIVE SYNTHESIS OF 2-SUBSTITUTED 3-NITROPYRIDINES BY ONE-POT REACTION OF EITHER 4- OR 6-SUBSTITUTED 1-METHYL-3,5-DINITRO-2-PYRIDONES WITH KETONES AND AMMONIA
Tohda, Yasuo,Kawara, Tooru,Eiraku, Miyuki,Tani, Keita,Ariga, Masahiro,Mori, Yutaka
, p. 2079 - 2082 (2007/10/02)
Regioselective synthesis of 2-substituted 3-nitropyridines was achieved by one-pot reaction of either 4- or 6-substituted 1-methyl-3,5-dinitro-2-pyridones with ketones in the presence of ammonia.The selectivity is interpreted in terms of steric factor of substituent on the pyridone.
Cytotoxic compounds. Part 21. Chloro-, methoxy-, and methoxy-carbonyl-derivatives of (bis-2-chloroethylamino)-phenols and -anilines
Abela Medici, Anthony J.,Owen, Leonard N.,Sflomos, Constantine
, p. 2258 - 2263 (2007/10/09)
New or improved syntheses are described of some NN-bis-2-chloroethylanilines carrying both a free phenolic group and a methoxycarbonyl ring substituent. A study has been made of the hydroxyethylation, with ethylene oxide, of a variety of chloro-, methoxy-, and methoxycarbonyl-nitroanilines, and of methoxy- and methoxycarbonyl-N-acylphenylenediamines. Bishydroxyethylation was inhibited by an o-methoxycarbonyl group and by an o- or p-nitro-group, but otherwise the NN-bis-2-hydroxyethyl derivatives were obtained and subsequently converted into the NN-bis-2-chloroethyl compounds. Reduction of the nitro-group, or hydrolysis of the acylamino-group, in these dichlorides led to NN-bis-2-chloroethylanilines carrying both a free amino-group and also a methoxycarbonyl-, methoxy-, or chloro-group as ring substituents. The ring-substituted (bis-2-chloroethylamino)-phenols or -anilines are precursors of mustard urethanes having potential importance as anti-tumour agents.
