4-Nitrophenyl phenyl ether

Outline a reasonable synthesis of 4 nitrophenyl phenyl ether from chlorobenzene and phenol... 

Diphenyl ether 2-Nitrophenyl phenyl ether 4-Nitrophenyl phenyl ether... 

Also in the diphenylether series, 4-nitrophenol in dry pyridine containing Cu(l)phenylacetylide after refluxing under nitrogen for 10 hours and then treatment with bromobenzene followed by further refluxing during 4 hours, furnished 4-nitrophenyl phenyl ether in 70-77% yield (ref.64). 

There has been a series of papers on the deoxygenation of 2-nitrophenyl phenyl ethers and sulphides. Of particular interest has been the role of pentacovalent intermediates (47) in these reactions. These are certainly not the primary intermediates in the reactions but are of great importance in determining the course of the reaction. Their genesis is thought to be that shown in Scheme 3.57... 

The aryl halide must be one that is reactive toward nucleophilic aromatic substitution by the addition-elimination mechanism. p-Fluoronitrobenzene is far more reactive than fluorobenzene. The reaction shown yields p-nitrophenyl phenyl ether in 92% yield. 

Quinoxalinones have been suggested for the chromatography of keto acids [184,185]. They are produced by reaction with aromatic o-diamines, as shown in Scheme 4.21 (p. 77). A solution of 60 mmol of sublimed o-phenylenediamine in 100 ml of 10% acetic acid was mixed with a solution of 30 mmol of the keto acid in 30 ml of water. The precipitated quinoxalinone was filtered after 15 min, washed with water, dried and crystallized from methanol. Prior to the GC analysis proper, it had to be converted into a silyl derivative 5—50 /ul of about a 1% solution of quinoxalinone in dry pyridine was mixed with 20 jul of a pyridine solution of the internal standard (6-methyl-2-naphthol, p-nitrophenyl phenyl ether). A 200-/lz1 volume of BSA and 50 of pyridine were added. As the silylation proceeded very quickly, the reaction mixture could be injected immediately. 

MeTHF has also been used as an alternative to dichloromethane in biphasic reactions including alkylations, amidations and nucleophilic substitutions. For example, 2-nitrophenyl phenyl ether was prepared in 95% yield using 2-MeTHF as the organic solvent through reaction of phenol and o-fluoronitrobenzene using tetrabutylammonium bromide as a phase transfer catalyst. 

PROBLEM 24.9 Which of the following two combinations of reactants is more appropriate for the preparation of p-nitrophenyl phenyl ether ... 

More recently, a PVC ISE based on the [4-(l,l,3,3-tetramethylbutyl) phenyl] phosphate/decan-l-ol system in conjunction with a chemometric technique has facilitated magnesium measurements (35). Attempts to make magnesium sensors with magnesium adducts of poly(propylene glycol) in conjunction with tributyl phosphate, di-octylphenyl phosphonate, its 3-nitrophenyl derivative, 2-nitroethyl benzene and 2-nitrophenyl phenyl ether solvents produced instead calcium sensors with = 0.06-0.08. 

All ammonium ISEs are based on the macrotetrolide antibiotics and their major applications relate to enzyme studies. PVC membranes with nonactin (18) (containing up to 28% monactin 19) have been fabricated with a wide range of solvents, namely diethyl-, dibutyl- and dioctyl phthalates dioctyl adipate dibutyl-, dioctyl- and diethylhexyl sebacates diethylhexyl- and tripentyl phosphates di-octylphenyl phosphonate and 2-nitrophenyl phenyl ether (49,50). In terms of selectivity, dioctyl adipate (DOA) was the best solvent, and the nonactin sensor could be conserved by fixing the mass ratios of nonactin DOA PVC at 1 300 160. The Nerntian slope was 57.5mV decade and kRH4,K = 0 H (50). 

Dissolve 0.1 g of the dried precipitate, 0.3 g o-nitrophenyl phenyl ether and 0.17 g PVC powder in 6 ml tetrahydrofuran (caution flammable toxic vapour). 

It should also be noted that there is the possibility of complications arising from reaction of the nucleophile with the solvent to give the lyate anions. For example, phenoxides may react with alcohols to form alkoxide ions, so that reaction of 4-nitrofluorobenzene with sodium phenoxide in methanol was found to give 99% of 4-nitroanisole and only 1 % of the nitrophenyl phenyl ether [58]. 

FIG. 10 Faradaic admittance coefficient Yq for the interface between 0.1 M LiCl in water and 0.02 M tetrabutylammonium tetraphenylborate ( ) or tetrapentylammonium tetrakis[3,5-bis(tri-fluoromethyl)phenyl]borate ( ) in o-nitrophenyl octyl ether as a function of the interfacial potential difference A y. (From Ref 73.)... 

The relative stability of l, 2 -epoxyvinylbital, and the great instability of its diol, can be gainfully compared with the fate of the corresponding metabolites of phenyl vinyl ether (10.69, R = H) and 4-nitrophenyl vinyl ether (10.69, R = N02), two mutagenic and tumorigenic compounds [144] [145]. Their primary metabolic route is by vinyl epoxidation to the corresponding... 

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