Phosphorus–nitrogen compounds. Part XXXV. Friedel–Crafts reactions of chlorodimethylaminocyclotriphosphazatrienes with benzene

Abstract

Chlorodimethylaminocyclotriphosphazatrienes, N3P3Cl6–n(NMe2)n(n= 1,2,2,3,3, and 3) undergo Friedel–Crafts reactions with benzene in the presence of anhydrous aluminium trichloride to give phenyldimethylamino-derivatives, N3P3PhmCl6–n–m(NMe2)n, whose structures are established by their 1H n.m.r. spectra. Replacement occurs readily at PCl·NMe2 groups and more slowly at PCl2 groups. The hydrocarbons triphenylmethane and diphenylmethane are minor by-products in these reactions but are the major products isolated from attempted Friedel–Crafts reactions of cis-non-geminal-N3P3Cl2(NMe2)4. The factors governing the positions of phenylation in the cyclotriphosphazatrienes are discussed.