600-20-4Relevant articles and documents
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.
REACTION D'OXIMATION DES CETONES V. MECANISME ET EFFETS DE STRUCTURE DANS LA REACTION DE DESHYDRATATION ACIDO-CATALYSEE DES CARBINOLAMINES
Lamaty, G.,Roque, J. P.,Natat, A.,Silou, T.
, p. 2667 - 2676 (2007/10/02)
The equilibrium constants of formation and the rate constants of dehydratation of carbinolamines resulting from the addition of hydroxylamine to 19 ketones, - 5 aliphatic, 5 aromatic and 9 cyclanic -, have been measured at 25 deg C in water/methanol 60/40 v/v.We show that the acid catalyzed process predominates in the range of pH 6 to 7 for acetophenones or pH 7 to 8.5 for saturated ketones.The rate constants ratios and Hammett ρ constant of the reaction suggest an sp3 (early) transition state.The changes in rate constant are discussed in terms of torsional and non-bonding steric effects.For several hindered ketones, e.g. 3,3,5,5-tetramethylcyclohexanone, we show the existence of a steric hindrance to the approach of the catalyst; in that case the result is a strong decrease of the rate of the dehydratation.
Alkylwanderungen bei Sextettumlagerungen
Langhals, Heinz,Range, Guenter,Wistuba, Eckehardt,Ruechardt, Christoph
, p. 3813 - 3830 (2007/10/02)
The migration aptitude of alkyl groups in the Beckmann-, the Criegee-, and the isonitrile-nitrile rearrangements were investigated.The relative rearrangement rates of substituted benzyl groups are an expression of the charge on the migrating carbon at transition state.From the relative rates of migration of exo- and endo-2-norbornyl groups the geometrical changes at the migrating carbon is estimated.Finally, the different influence of α-branching in the migrating group is discussed for these and some other rearrangements.