REACTIVITY OF ORGANOPHOSPHORUS COMPOUNDS .25. DISPLACEMENT OF ACTIVATED AROMATIC NITRO-GROUPS BY TERVALENT PHOSPHORUS REAGENTS

A novel displacement of certain activated aromatic nitro-groups by tervalent organophosphorus reagents is described. Thus trimethyl, triethyl, and tri-isopropyl phosphites, diethyl methylphosphonite, and ethyl diphenylphosphinite react with increasing ease [(RO)3P < (EtO)2PMe < [tOPPh2] with o-dinitrobenzene to give high yields of the corresponding dialkyl o-nitrophenylphosphonates. ethyl P-methyl-o-nitrophenylphosphinate, and o-nitrophenyldiphenylphosphine oxide, respectively, and ethyl nitrite. 1,2,4-Trinitrobenzene undergoes similar displacements to give 2,4-dinitrophenyl derivatives. Under comparable conditions p-dinitrobenzene and o-chloronitrobenzene do not undergo these reactions other than, possibly, to a very minor extent.