2.4- dinitrophenyl phenyl

The number of reactions that fit into this second class are manifold. Some typical examples are the amine-catalyzed reactions of 2,4-dinitrochlorobenzene with n-butylamine in chloroform (k"/k = 2.59 l.mole-1)23, with allylamine in chloroform (k"jk — 4.60 l.mole-1)24 and with allylamine in ethanol (k"fk =0.36 l.mole-1)25 and the amine-catalyzed reaction of p-nitrofluorobenzene with piperidine in polar solvents (k"/k < 3.2 l.mole-1)26. A typical example of a strongly catalyzed system is the reaction of 2,4-dinitrophenyl phenyl ether with piperidine in 60 % dioxan-40 % water27. 

If one limits the consideration to only that limited number of reactions which clearly belong to the category of nucleophilic aromatic substitutions presently under discussion, only a few experimental observations are pertinent. Bunnett and Bernasconi30 and Hart and Bourns40 have studied the deuterium solvent isotope effect and its dependence on hydroxide ion concentration for the reaction of 2,4-dinitrophenyl phenyl ether with piperidine in dioxan-water. In both studies it was found that the solvent isotope effect decreased with increasing concentration of hydroxide ion, and Hart and Bourns were able to estimate that fc 1/ for conversion of intermediate to product was approximately 1.8. Also, Pietra and Vitali41 have reported that in the reaction of piperidine with cyclohexyl 2,4-dinitrophenyl ether in benzene, the reaction becomes 1.5 times slower on substitution of the N-deuteriated amine at the highest amine concentration studied. 

However, neither copper(I) iodide nor photostimulation are absolutely necessary for the arylation of benzenetellurolate. Lithium benzenetellurolate and 1,2-bromoiodobenzene condensed in tetrahydrofuran at 20° to form 1,2-bis[phenyltelluro]benzene in 32% yield3. Sodium benzenetellurolate condensed similarly with l-chloro-2,4-dinitrobenzene at 20° in tetrahydrofuran/aqueous sodium hydroxide in the presence of a phase-transfer reagent. In this case 2,4-dinitrophenyl phenyl tellurium (m.p. 134°) was isolated in 30% yield4. Lithium methanetellurolate was arylated in tetrahydrofuran by iodobenzene5, 1,2-dibromobenzene, and l-bromo-2-methoxybenzene at 20°3. 

Dimethyl sulfide N,N -Di-P-naphthyl-p-phenylenediamine 2,4-Dinitrophenyl phenyl sulfide Ethyl-N-butylamine 2-Ethylhexanal 2-Ethylhexenal 2-Ethyl-2-hexenal Ethyl vinyl ketone Formamide Glyceryl-a-monochlorohydrin... 

The Br0nsted-type plot for the aminolysis of 2,4-dinitrophenyl phenyl carbonate by a series of pyridines in H2O/DMSO (4 1) at 298 K exhibited a downward curvature ()32 = 0.84, /Sj = 0.16) centred at pK 8.5, typical for reactions proceeding through a stepwise mechanism with a change in the rate-determining step from breakdown to formation of the tetrahedral zwitterionic intermediate. ... 

Figure 2. Reaction of 2,4-dinitrophenyl phenyl ether with piperidine, catalysed by NaOH.

Table 3. Reaction between piperidine and 2,4-dinitrophenyl phenyl ether.

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