233-70-5Relevant academic research and scientific papers
Microwave-assisted efficient one-step synthesis of amides from ketones and benzoxazoles from (2-hydroxyaryl) ketones with acetohydroxamic acid using sulfuric acid as the catalyst
Madabhushi, Sridhar,Chinthala, Narsaiah,Vangipuram, Venkata Sairam,Godala, Kondal Reddy,Jillella, Raveendra,Mallu, Kishore Kumar Reddy,Beeram, China Ramanaiah
experimental part, p. 6103 - 6107 (2011/11/30)
Efficient one-step method for the synthesis of amides directly from ketones and benzoxazoles from (2-hydroxyaryl) ketones by the reaction of acetohydroxamic acid using sulfuric acid as catalyst was described.
Thermal transformation of cyclopropylazoarenes into the five-membered nitrogen-containing heterocycles
Novikov,Klimenko,Shulishov,Korolev,Tomilov
experimental part, p. 1718 - 1724 (2011/04/23)
Cyclopropylazoarenes containing methoxy groups in the aromatic ring give the corresponding N-arylpyrazolines on the reflux in o-dichlorobenzene or on SnCl2 catalysis at 80 °C in good yields. The products can be smoothly oxidized into the corresponding pyrazoles. Thermolysis of cyclopropylazoarenes containing hydroxy groups in the aromatic ring proceeds more complicated. Thus in the case of resorcin azo derivative, strong resinification of the reaction mixture is observed and the corresponding N-arylpyrazoline is isolated only in -40% yield. Under similar conditions, thermolysis of 1-cyclopropyl- and 1-(1-methylcyclopropyl)azo-2-naphthol proceeds otherwise and unexpectedly leads to naphtho[1,2-d]oxazole derivatives with degradation of the cyclopropane ring.
Flash vacuum pyrolysis of azo and nitrosophenols: New routes towards hydroxyarylnitrenes and their reactions
Ibrahim, Yehia A.,Al-Awadi, Nouria A.,Kual, Kamini
, p. 5425 - 5430 (2007/10/03)
Flash vacuum pyrolysis of phenylazonaphthols and nitrosonaphthols at 700°C and 0.02Torr yielded quinoline, isoquinoline, indene and naphthols (and aniline only from the phenylazo derivatives). Similar FVP of p-nitroso and p-phenylazophenol gave pyridine.
Study of the Fatigue Process and the Yellowing of Polymeric Films Containing Spirooxazine Photochromic Compounds
Baillet, Gilles,Giusti, Gerard,Guglielmetti, Robert
, p. 1220 - 1225 (2007/10/02)
Photochromic polyurethane films containing 5-substituted 1,3-dihydro-3,3-dimethyl-1-alkylspiropyridobenzoxazine> and 1,3-dihydro-1,3,3-trimethylspironaphthoxazine> were degraded under xenon light exposure.The loss of the photochromic response was monitored by spectrophotometry as a function of the irradiation time; meanwhile, the photoproduct formation and the amount of photochromic material still available were analyzed by chromatography after liquid-solid extraction.At the same time, the fade rateswere monitored after flash-excitation photolysis or after the photostationary state during degradation.It was clearly demonstrated that the loss of photochromism was due exclusively to a photooxidation process of the initial dye, and not to an acceleration of the bleaching or a potential screen effect caused by the photoproducts.
Oxidative degradation of organic photochromes
Malatesta,Milosa,Millini,Lanzini,Bortolus,Monti
, p. 303 - 310 (2007/10/02)
Photo-oxidation of some representative spiropyrans and spiro-oxazines does not seem to involve singlet oxygen O2(1Δg). The photochromes rather behave, in the spiro and merocyanine form, as O2(1Δg) quenchers. Only a methoxy-nitro benzopyran derivative was found to promote formation of singlet oxygen. Superoxide anion O2 is likely the activated oxygen species responsible for their oxidative photodegradation.
