2.4- Dinitrophenyl ethers

Dinitrophenyl ethers. 2 4-Dinitrochlorobenzene reacts with the sodium salts of phenols to yield crystalline 2 4-dinitrophenyl ethers ... 

Dissolve 1 g. (or 0 01 mol) of the phenol in a solution of 0-40 g. of sodium hydroxide in 5 ml. of water. Add the resulting solution to 2-Og. of 2 4-dinitrochlorobenzene dissolved in 30 ml. of 95 per cent, ethanol add more alcohol, if necessary, to effect solution. Heat the solution under reflux on a water bath until the colour (usually red) is discharged and a copious precipitate of sodium chloride appears (30-60 minutes). Dilute the reaction mixture with an equal volume of water, filter off the precipitated 2 4-dinitrophenyl ether, wash with water, and recrystallise from alcohol. 

Dinitrophenyl 2y-iodo-3y-methyl-4y-nitro-6y-isopropylphenyl ether [69311-70-2]... 

Electron Transport Between Photosystem I and Photosystem II Inhibitors. The interaction between PSI and PSII reaction centers (Fig. 1) depends on the thermodynamically favored transfer of electrons from low redox potential carriers to carriers of higher redox potential. This process serves to communicate reducing equivalents between the two photosystem complexes. Photosynthetic and respiratory membranes of both eukaryotes and prokaryotes contain stmctures that serve to oxidize low potential quinols while reducing high potential metaHoproteins (40). In plant thylakoid membranes, this complex is usually referred to as the cytochrome b /f complex, or plastoquinolplastocyanin oxidoreductase, which oxidizes plastoquinol reduced in PSII and reduces plastocyanin oxidized in PSI (25,41). Some diphenyl ethers, eg, 2,4-dinitrophenyl 2 -iodo-3 -methyl-4 -nitro-6 -isopropylphenyl ether [69311-70-2] (DNP-INT), and the quinone analogues,... 

Purified by distn and by recrystn from pet ether. The bis-2,4-dinitrophenyl hydrazone has m 221 dec. [Halford and Weissmann J Org Chem 17 1646 1952 Riemschneider and Kassahn Chem Ber 92 1705 7959.]... 

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. 

B. 2,4-Dinitrobenzenesulfenyl chloride. Dry 2,4-dinitrophenyl benzyl sulfide (232 g., 0.80 mole) and 400 ml. of dry ethylene chloride are placed in a 2-1., one-necked, round-bottomed flask equipped with a stirrer (Note 3). Sulfuryl chloride (119 g., 0.88 mole) (Note 4) is added to the resulting suspension at room temperature. A mildly exothermic reaction causes the solid to dissolve quickly, usually within 1 to 2 minutes, with a temperature rise of 10-15° (Note 5). The resulting clear yellow solution is concentrated to an oil by heating under aspirator vacuum on a steam bath (Note 6). Caution Do not heat with gas or electricity because the product, like many nitro compounds, can explode if overheated.) The residual oil is cooled to 50-60°, and 3-4 volumes of dry petroleum ether (b.p. 30-60°) are added with vigorous handswirling. The oil quickly crystallizes. The mixture is cooled to room temperature and filtered to separate 2,4-dinitrobenzene-sulfenyl chloride as a yellow crystalline solid. The sulfenyl chloride is washed well with dry petroleum ether and dried at 60-80° (Note 7) weight 150-170 g. (80-90%) m.p. 95-96° (Notes 8, 9). 

Excited-state intramolecular nucleophilic aromatic substitutions are known as photo-Smiles rearrangements. Ealier, these were reported for 2,4-dinitrophenyl ethers and. v-lriazinyl ethers32. The exploratory33 and mechanistic34 studies on photo-Smiles rearrangements of p-(nitrophenoxy)- >-anilinoalkanes were carried out (equation 28). 

A similar twisting was expected to occur with the phenoxy ether to explain the greater reactivity of the 2,6-isomer in recent studies of the reactions of 2,4-dinitro and 2,6-dinitrophenyl phenyl ethers with zz-butylamine109. Nevertheless, in this case, the authors... 

Dinitrofluorobenzene (DNFB) reacts with phenols and, which is not of interest here, with amino groups. Hydrogen fluoride is eliminated. DNFB does not react w ith carboxylic acids. Alcohols, if they react at all, form dinitrophenyl ethers very slowly. Very weakly dissociated phenolic hydroxyl groups, e.g., in salicylic acid (pK = 13.4), are inert towards DNFB. 

Hydroxy-l,2,3,4-tetrahydroquinolines 304 were obtained by cyclization of oxime 2,4-dinitrophenyl ethers 303 in the presence of system NaBH3CN/NaH/l,4-dioxane (equation 131) . If the reductive cyclization was followed by oxidation with DDQ (2,3-dichloro-4,5-dicyano-p-benzoquinone) the corresponding 8-hydroxyquinolines 305 were obtained . ... 

Bicyclo[3.3 l]nonan-9-one, (2,4-dinitrophenyl)hydrazone (8,9) (—) Monochloroborane diethyletherate Borane, chloro-, compound with ethyl ether (8), Borane, chloro-, compound with 1,1 -oxybis[ethane] (1 1) (9) (36594-41-9). 

Dinitrophenyl-l,3-di(/3-hydroxyethyl) -ether. One of the names for 1,3-Bis(2-hydroxyethoxy)-4,6-dinitrobenzene, described in Vol 2, p B145-R... 

N)3,C6H2.0.C6Hs(N02)2 lflts (from eth acet), mp 200—204° insol in w si sol in ale or eth sol in benz, toluene Nitrobenzene can be prepd by nitration of 3,4-dinitrophenyl-ether with mixed nitric-sulfuric acid at 110°... 

Stability of the compounds 86 varies dramatically with the nitrogen substituent. Methyl" and phenyl s derivatives (86 R = Me or Ph) are moderately stable crystalline solids—often hydrated (87 or 88 X = OH). The 2,4-dinitrophenyl derivative [86 R = C6H3(NO2)2, R = H] is less stable but can be isolated as orange prisms (mp 112°C)5° It readily rearranges to the diaryl ether 96 (mp 128°C) with which it was originally confused.5The monomeric 5-nitro-2-pyridyI derivative is similarly unstable and in solution dimerizes giving adduct 97a. 5 5 The 4,6-di-methylpyrimidin-2-yl derivative can only be isolated as the dimers 97b and... 

T etrctnitro-4-acetamidodiphenyl-ether or 3.5-Dinitro-4-acetamidophenol-[2 4 -dinitrophenyl -ether, CHa. CO. NH. ... 

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