4-dimethylaminophenyl 4-nitrophenyl

As would be expected in a substrate with a poor leaving group the predominant elimination process is of the Hofmann type. However, the authors did find some unexpected reactions. For example, the p-nitrophenyl sulphone was completely consumed within six hours of heating with the glycolate system, yet alkenes formed only a minor part of the products, the major part not being clearly identified. The p-dimethylaminophenyl sulphone was three to six times more reactive than the other sulphones, but it also underwent elimination at a significant rate with either solvent, even in the absence of alkoxides. The reasons for this are obscure. 

As regards the electrooxidation of the corresponding monomers, they have less anodic Epa values than N-phenylpyrrole even with the nitro substituent and the reactions remain irreversible. The substituents influence the oxidation of these monomers much more than was observed with pentaphenylpyrrole. For example, substitution of a p-methoxy group in the N-phenyl of die latter produces a 20 mV cathodic shift in the Epa value (10). The dimethylaminophenyl and nitrophenyl groups show reversible redox behavior and appear to behave independent of the pyrrole moiety in these derivatives. 

Electrolysis of 4-dimethylaminobenzaldehyde 4-nitrophenylhydrazone (370) forms the 1,3-diaryl-nitrilimine, which in the presence of imidazole forms 3-(4-dimethylaminophenyl)-l-(4-nitrophenyl)-7,7a-dihydro-l//-imidazo[2,l-c][l,2,4]triazole (371) by a [3 + 2] cycloaddition reaction (Scheme 35)... 

Scheme 1.167). There was no evidence for acylation of the oxazole ring. In contrast, formylation of 5-(4-dimethylaminophenyl)-2-(4-nitrophenyl)oxazole 615 effects Vilsmeier-Haack formylation of the oxazole ring as well as the electron-rich A, A -dimethylaniline. In this case, heterocyclization then leads to the observed quinazolinium salt 616. " ... 

Diphenyldisulfide reacted slowly while di-(i T,A/ -dimethylaminophenyl) disulfide reacted more readily. When R is ethyl, benzyl, o-nitrophenyl, p-nitrophenyl, dibenzhydryl, benzthiozoyl, 9-fluorenyl, or antipyryl, the disulfide is stable to treatment with triphenylphosphine for 10 hours at 80° C, and no monosulfide is produced. Electron-donoring groups in the phosphine also increase the rate of reaction. Disulfides of the type R(S=)C—S—S—C(==S)—R react very quickly with phosphines. Triphenylphosphine will remove the sulfur from an ethylene sulfide... 

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