Novel, directed synthesis of unsymmetrical azoxyalkanes and azoxyaralkanes from N,N-dihaloamine and nitroso precursors

Methylenecyclopropane Rearrangement as a Probe for Free Radical Substituent Effects. σ • Values for Potent Radical-Stabilizing Nitrogen-Containing Substituents

“…p -( tert -Butyl-ONN-azoxy)benzaldehyde (26) was prepared by a modification of the method of Kovacic . A solution of 1 g of p -( tert -butylazo)benzaldehyde, 25 , in 30 mL of methylene chloride was cooled to 0 °C, and 1.8 g of 50% m -chloroperbenzoic acid (1.0 equiv) was added.…”

Aliphatic azoxy compounds. IV. Reaction of nitrosoalkanes with hydroxylamines. Synthesis of unsymmetrical primary and secondary azoxyalkanes by nitrogen-nitrogen bond formation

“…The nitrosoalkane monomer, though it condenses with the alkylhydroxylamine, does tautomerize to the corresponding (unreactive) oxime during these condensations. Thus, cyclohexanone oxime was detected (5-10% by VPC) in the reaction mixtures of entries 5-7 of Table I as was benzaldehyde oxime (entry 9) and acetophenone oxime (entries 10 and 11). The benzylictype nitrosoalkane dimers of entries 9-11 of Table I were chosen, in part, to provide a test of the method with easily tautomerized and photolytically cleaved nitrosoalkane monomers.…”

Chemistry of N-halo compounds. XXV. Regiospecific synthesis of unsymmetrical azoxy compounds (diazene N-oxides)

“…By the condensation of a tertiary alkyl or aryl nitroso substrate with an N,N-dihalo amine derivative, various types of azoxy compounds (Table I) have been prepared. In addition to the base-sensitive ester (3), amide (5), and acyl derivative (4), we have synthesized members containing two azoxy moieties (10 and 11) (Table II), and the interesting compound "chloroazoxobenzene" (8) in a yield superior to that reported in the only other published procedure. 6 The method also works with MAI-dibromo compounds as shown in Table III.…”