72215-86-2Relevant articles and documents
Sterically hindered aromatic compounds. XI. Spectral and product studies of the decomposition of N-nitrosoacetanilides
Barclay, L. Ross C.,Dust, Julian M.
, p. 607 - 615 (2007/10/02)
Decomposition of N-nitroso-2,4,6-tri-tert-butylacetanilide (1) in benzene forms products 2,4,6-tri-tert-butylphenyl acetate (3), 3-(3,5-di-tert-butylphenyl)-2-acetoxy-2-methylpropane (4), and hydrocarbons 3-(3,5-di-tert-butylphenyl)-and 1-(3,5-di-tert-butylphenyl)-2-methylpropene (5 and 6) explained by a reactive aryl cation (2), the rearranged products (4, 5, 6) originating from a 1,5-hydride shift from an ortho tert-butyl group in 2.In contrast, decomposition of 1 in triethylamine forms products 1,3,5-tri-tert-butylbenzene (10), 2,4,6-tri-tert-butylacetanilide (15), and 2-(3,5-di-tert-butylphenyl)-2-methylpropanal oxime (13), expected of a free radical pathway.Electron spin resonance evidence is given for intermediates formed by rearrangement of the 2,4,6-tri-tert-butylphenyl radical and spin trapped by the nitroso group of 1.CIDNP and esr studies on the dediazoniation of N-nitrosoacetanilide and aniline in the presence of tertiary amines support the proposed electron transfer mechanism.The results are briefly discussed in terms of the role of steric effects and electron transfer in the dediazoniation of nitrosoacetanilides and diazonium salts.
Chemistry of Sulfenic Acids. 3. Studies of Sterically Hindered Sulfenic Acids Using Flash Vacuum Pyrolysis
Davis, Franklin A.,Jenkins, Robert H.,Rizvi, Syed Q. A.,Yocklovich, Steven G.
, p. 3467 - 3474 (2007/10/02)
Flash vacuum pyrolysis (FVP) of sulfoxides containing β-hydrogen atoms affords sulfenic acids (RSOH) in good concentration under conditions where they are stable.The application of this technique to the synthesis and study of sterically hindered sulfenic acids 12a-e is described.The principal or primary reaction of simple sulfenic acids prepared in this manner is dehydration to thiosulfinates 13 (eq 1).Steric inhibition to dehydration (eq 1) appears to only be of importance for 2-methyl-2-propanesulfenic acid (12a) which was trapped in good yield with methyl propiolate to afford 16a. 2,4,6-Tri-tert-butylbenzenesulfenic acid (12e) appears to be destabilized as a consequence of interaction between the SOH and adjacent tert-butyl groups.In the pyrolysis section of the apparatus, 12e decomposes to phenol 21 and aryl radical 22, which reacts further.Thermolysis of sulfoxides generates the sulfenic acids 12a-e in very low concentration at any one time.The products of sulfenic acids generated in this way result from secondary reactions of the corresponding thiosulfinates.
