Diphenyl mixtures

Phenyl ether-diphenyl mixture (vapour) Phenylethylene, see Styrene, monomer Phenyl glycidyl ether Phenylhydrazine Phosdrin (Mevinphos )... 

SYNONYMS diphenyl oxide-diphenyl mixture, dowtherm A. 

Synonyms/Trade Names Diphenyl oxide-diphenyl mixture, Dowtherm A ... 

Diphenyl. Reflux a mixture of 1 g, of diphenyl, 2 ml. of glacial acetic acid and 0 -5 ml. of fuming nitric acid for 10 minutes. Pour into 20 ml. of cold water, filter oflF the precipitate, wash it with cold water imtil free from acid, and recrystallise from alcohol. The product is 4-nitrodiphenyl, m.p. 114°,... 

Difluorodiphenyl. Bis-diazotise a solution of 46 g. of benzidine (Section IV,88) in 150 ml. of concentrated hydrochloric acid and 150 ml. of water by means of a solution of 35 g. of sodium nitrite in 60 ml. of water add about 200 g. of crushed ice during the process (compare p-Fbtorotoluene above). Filter the solution and add it to a filtered solution of 85 g. of sodium borofluoride in 150 ml. of water. Stir for several minutes, collect the precipitated bis-diazonium borofluoride by suction filtration, wash with 5 ml. of ice-cold water, and dry at 90-100°. Place the dry salt in a flask fitted with an air condenser, immerse the flask in an oil bath, and slowly raise the temperature to 150° (Fume Cupboard ). When decomposition of the salt is complete, steam distil the mixture collect the 4 4 difluoro-diphenyl which passes over and recrystallise it from ethanol. The yield is 21 g., m.p. 92-93°. 

Place 125 ml. of glacial acetic acid, 7 -5 g. of purifled red phosphorus (Section II,50,d) and 2 5 g. of iodine in a 500 ml, round-bottomed flask fitted with a reflux condenser. Allow the mixture to stand for 15-20 minutes with occasional shaking until aU the iodine has reacted, then add 2 5 ml. of water and 50 g, of benzilic acid (Section IV,127). Boil the mixture under reflux for 3 hours, and filter the hot mixture at the pump through a sintered glass funnel to remove the excess of red phosphorus. Pour the hot filtrate into a cold, weU-stirred solution of 12 g. of sodium bisulphite in 500 ml, of water the latter should be acid to litmus, pro duced, if necessary, by passing sulphur dioxide through the solution. This procedure removes the excess of iodine and precipitates the diphenyl-acetic acid as a fine white or pale yellow powder. Filter the solid with suction and dry in the air upon filter paper. The yield is 45 g., m.p. 

Propiophenone. Prepare a solution of diphenyl-cadmium in 110 ml. of dry benzene using 4 9 g. of magnesium, 32 4 g. of bromobenzene and 19 5 g. of anhydrous cadmium chloride. Cool the solution to 10°, and add during 3 minutes a solution of 14 -8 g. of propionyl chloride (b.p. 78-79°) in 30 ml. of dry benzene use external coohng with an ice bath to prevent the temperature from rising above 40°. Stir the mixture for 2 hours at 25-35°. Work up the product as detailed above except that 6 per cent, sodium carbonate solution should replace the saturated sodium bicarbonate solution. The yield of propiophenone, b.p. 100-102°/16 mm., is 17 6 g. 

Acyl halides are intermediates of the carbonylations of alkenes and organic-halides. Decarbonylation of acyl halides as a reversible process of the carbo-nylation is possible with Pd catalyst. The decarbonylation of aliphatic acid chlorides proceeds with Pd(0) catalyst, such as Pd on carbon or PdC, at around 200 °C[109,753]. The product is a mixture of isomeric internal alkenes. For example, when decanoyl chloride is heated with PdCF at 200 C in a distillation flask, rapid evolution of CO and HCl stops after I h, during which time a mixture of nonene isomers was distilled off in a high yield. The decarbonylation of phenylpropionyl chloride (883) affords styrene (53%). In addition, l,5-diphenyl-l-penten-3-one (884) is obtained as a byproduct (10%). formed by the insertion of styrene into the acyl chloride. Formation of the latter supports the formation of acylpalladium species as an intermediate of the decarbonylation. Decarbonylation of the benzoyl chloride 885 can be carried out in good yields at 360 with Pd on carbon as a catalyst, yielding the aryl chloride 886[754]. 

The plastici2er performance of isopropylphenyl diphenyl phosphate [28108-99-8], [68937-41-7], [68782-95-6], C2 H2 04P, is close to that of tricresyl phosphate. It is made from the product of isopropylation of phenol by propylene. The phosphate is a mixture of mainly 0- and -isomers and contains a distribution of different levels of alkylation (101,102). 

Dowtherm LE is a mixture of diphenyl oxide and methylated biphenyl for use in Hquid-phase systems. The low crystal point and low viscosity obviate protection from freezing at temperatures down to —30°C. 

For methylene diphenyl diisocyanate (MDI), the initial reaction involves the condensation of aniline [62-53-3] (21) with formaldehyde [50-00-0] to yield a mixture of oligomeric amines (22, where n = 1, 2, 3...). For toluene diisocyanate, amine monomers are prepared by the nitration (qv) of toluene [108-88-3] and subsequent hydrogenation (see Amines byreduction). These materials are converted to the isocyanate, in the majority of the commercial aromatic isocyanate phosgenation processes, using a two-step approach. 

Aromatic polysulfites can be produced if bisphenols, eg, bisphenol A, are heated with diphenyl sulfite in the presence of lithium hydride (112). Halosulfates and Halosulfites. A general method for the preparation of alkyl halosulfates and halosulfites is the treatment of the alcohol with sulfuryl or thionyl chloride at low temperatures while passing an inert gas through the mixture to remove hydrogen chloride (113). 

Condensing Organic Va.por, The eutectic mixture of diphenyl and diphenyl oxide is an excellent vapor medium for precise temperature control at temperatures higher than those practical using steam. This mixture can achieve 315°C while holding pressure at 304 kPa (3 atm) absolute. In contrast, steam would require 10.6 MPa (105 atm) pressure. 

Photolysis of 2,3-diphenyl-A -azirine (442) generates benzonitrile ylide (443). Irradiation in the presence of ethyl cyanoformate resulted in a mixture of the oxazoline (444) and the imidazole (445) by 1,3-dlpolar cycloaddition to the carbonyl and nitrile group, respectively (72HCA919). 

A mixture of 56.8 g (0.21 mol) of diphenyl phosphorochloridate (Note 1), 16.3 g (0.25 mol) of sodium azide, and 300 mL of anhydrous acetone (Note 2) in a 500-mL round-bottomed flask fitted with a calcium chloride tube is stirred at 20-25°C for 21 hr. The lachrymatory mixture is filtered in a hood, and the filtrate is concentrated under reduced pressure. The residue is distilled through a short Vigreux column (Note 3). The yield of diphenyl phos-phorazidate, bp 134-136 C (0.2 ram), is 49-52 g (84-89 ) (Note 4). 

The crude enamlne (1) is dissolved in 20 mL of toluene, and the solution is transferred (Note 3) to a 100-mL, three-necked flask equipped with a magnetic stirring bar, 50-mL dropping funnel, reflux condenser protected with a calcium chloride tube, and a thermometer immersed in the solution. A solution of 13.2 g (0.048 mol) of diphenyl phosphorazidate (Note 4 uarntng) in 20 mL of toluene is added with stirring during 30 min di11e the reaction temperature is maintained at about 25°C. The mixture is stirred for 4 hr at 25 C and heated at reflux for 1 hr. The mixture is transferred to a 300-mL, round-bottomed flask and most of the toluene is removed under reduced pressure to yield 23.7 g of a reddish-brown oil, 2 (Note 5). 

The computer results from Table 5-13 show the calculated compositions of benzene, diphenyl, triphenyl, and hydrogen. At a fixed feedrate, increasing V/F values correspond to movement through the plug flow reactor (i.e., increasing reactor volume). Thus, these results illustrate how the composition varies with position in the reactor. Here, the mole fraction of benzene decreases steadily as the reaction mixture progresses in the reactor, while the composition of diphenyl increases and reaches a maximum between 1,684 and 1,723 hr and thereafter decreases. This is often typical of an intermediate in consecutive reactions. 

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