OXIDATIVE REARRANGEMENT OF PRIM-AMIDES AND ANODIC OXIDATION OF SYM-DISUBSTITUTED HYDRAZINES IN NONAQUEOUS SOLUTIONS

The oxidative rearrangement of amides with iodosobenzene diacetate (IBDA) and its derivatives was found to afford a useful alternative to the Hofmann, Curtius, Schmidt, and Lossen Rearrangement and to the oxidative rearrangement of amides with lead tetraacetate. The iodosobenzene diacetates were prepared chemically by the reaction of iodobenzenes with a mixture of hydrogen peroxide and acetic anhydride. IBDA was also prepared electrochemically by anodic oxidation of iodobenzene in acetic acid. A linear relationship between the cathodic E(,p/2) and (sigma)+ of the iodosobenzene dicarboxylates was observed. In general, the dicarboxylates with more positive cathodic E(,p/2) gave higher yields of prim-amines in the oxidative rearrangement of prim-amides in acetonitrile-water solutions. The iodosobenzene dicarboxylates were formed from IBDA in situ during the oxidative rearrangement of prim-amides with IBDA in the presence of an excess of carboxylic acids. The possible catalytic role of iodobenzene in an electrochemically driven oxidative rearrangement of prim-amides was also investigated. Azines and ketazines, precursors of sym-1,2-disubstituted hydrazines, were prepared by the reaction of carbonyl compounds with aqueous hydrazine in acidic methanolic solutions. sym-1,2-Disubstituted hydrazines were prepared by the reduction of the corresponding azines and ketazines, or reductive hydrazination of the corresponding carbonyl compounds with sodium cyanoborohydride under controlled pH conditions. The anodic oxidation of sym-1,2-disubstituted hydrazines under controlled potential in acetonitrile gave the corresponding azo compounds and the denitrogenated hydrocarbons. Anodic oxidation of 1,2-dibenzylhydrazine in methanol solution gave 1,2,4,5-tetrabenzyl-1,2,4,5-tetrahydrotetrazine (87) in 91% yield. Electrolysis of 1,2-dibenzylhydrazine at +0.6V vs Ag/Ag+ in acetonitrile solution gave 1,2-dibenzyl-3,4-diphenyl-1,2-diazedine (88) and benzaldehyde benzalhydrazone (89)