Aniline, formation Benzophenone

The photoreduction of nitrobenzene using p5o ex filtered light from a medium pressure mercury arc was studied in petroleum, toluene, ether, 2-propanol, tert-butyl alcohol, diethylamine, triethylamine, aqueous solutions of 2-propanol and diethylamine and also in aqueous t-butylalcohol containing sodium boro-hydiide 3 >. Varying amounts of aniline, azo- and azoxybenzene were obtained. In the presence of a fourty-fold excess of benzophenone, a six-fold increase in the rate of aniline formation in ethereal solution was observed, and aniline formation was completely suppressed by addition of biacetyl or octafluomaphthalene Since unreacted nitrobenzene could be recovered in these experiments, it is demonstrated that the triplet state of nitrobenzene was quenched. 

The most characteristic reactions for these compounds are thermolysis and decomposition under the action of both acids and nucleophilic reagents. 1,2,4-Dioxazolidines 15 are thermally stable only below 100 °C. The thermolysis of compound 15a in solution at 130 °C afforded benzophenone and benzamide in quantitative yields. The formation of these products is consistent with a radical mechanism involving initial 0-0 homolysis (Scheme 21). The base-catalyzed decomposition of compound 15a afforded the same products. Similar results were observed for the decomposition of compounds 15b and 15c. The interaction of dioxazolidine 15a with triphenylphosphine resulted in deoxygenation of the system with the concomitant formation of benzophenone and its imine with aniline <1995J(P1)41>. 

The simple conversion of aryl halides to anilines can be achieved through the formation of benzophenone imine adducts in the reaction of benzophe-... 

One strategy to prepare protected anilines is the reaction of diallylamine with aryl halides using the catalysts best suited for reactions of secondary amines. " The formation of N-aryl benzophenone imines by Pd-catalyzed C—N bond formation is a second strategy that allows for straightforward deprotection to the parent aniline. Benzophenone imine is commercially available. 

---