Dimethyl-1,1-biphenyl

Kim, C.-K., Y.-J. Cho, and Z-G Gao. 2001. Preparation and evaluation of biphenyl dimethyl dicarboxylate microemulsions for oral delivery . Cont. Rel70 149-155. 

Biphenyl Dimethyl methyl m-Methoxyphenol Stearic acid... 

Biphenyl dimethyl dicarboxylate Heaptoprotective Tween 80, Triacetin, MCT 4-fold improvement in AUC as compared to suspension [98]... 

Chi, S.C., Enhanced dissolution rate of biphenyl dimethyl dicarboxylate using SMEDDS, Adv. Eormulation Dev. Poorly-Soluble Drugs, 92, 79, 1999. 

N,N-bis(4-methylphenyl)-N,iV-bis(4-ethylphenyl)-[l,l -(3,3 -dimethyl)biphenyl]-4,4 -diamine [115310-63-9] (ETPD) (8) -doped PMPS (Table 1, entry 22), hole mobihty approaching 10 cm /Vs at 2.5 x 10 V/cm was observed (48). This is the highest recorded hole mobihty for disordered organic systems. From this perceptive, it is very interesting to study the carrier mobihty of polymers heavily doped with semiconductor nanoclusters. 

Milling Red SWB l-[4-[4-[4-toluenesulfonyloxy]phenylazo](3,3 dimethyl-l,l -biphenyl)-4 -azo]-2-hydroxynaphthalene-6,8-disulfonic acid di-Na salt, Acid Red 114 [6459-94-5] M 830.8, m dec >250", Cl 23635, X,max 514nm. Salted out three times with sodium acetate, then repeatedly extracted with EtOH. [McGrew and Schneider J Am Chem Soc 72 2547 1950.] See Solochrome Violet R on p. 352 in Chapter 4. 

Liver cancer can also be a consequence of exposure to hepatotoxic chemicals. Natural hepatocarcinogens include fungal aflatoxins. Synthetic hepato-carcinogens include nitrosoamines, certain chlorinated hydrocarbons, polychlorinated biphenyls (PCBs), chloroform, carbon tetrachloride, dimethyl-benzanthracene, and vinyl chloride.Table 5.15 lists the chemical compounds that induce liver cancer or cirrhosis in experimental animals or... 

Polybibenzoates are a kind of thermotropic polyesters obtained by polycondensation of 4,4 -biphenyldicar-boxylic acid (p,p -bibenzoic acid) with a diol. These polyesters contain the biphenyl group, which is one of the simplest mesogens. They are synthesized by melt transesterification of the dimethyl or diethyl ester of p,p -bibenzoic acid and the corresponding diol, using a titanium compound as catalyst, according to the following scheme ... 

Heteroaromatic diazonium salts can also be used for Gomberg-Bachmann aryla-tions. Fukata et al. (1973) refluxed 3,5-dimethyl-4-diazopyrazole (10.27) in benzene and obtained 3,5-dimethyl-4-phenylpyrazole (10.28, 36%), biphenyl (10.29, 17%), 3,5-dimethylpyrazole (10.30, 12%), and pyrazolo[4,3-c]pyrazole (10.31, 15%). In nitrobenzene the three isomeric 3,5-dimethyl-4-(nitrophenyl)-pyrazoles were formed in the ratio o m p = 10 3 3. In the opinion of Fukata et al. this ratio and the course of the reaction indicate a homolytic process. The present author thinks that the data do not exclude a competitive heterolytic reaction with the pyrazolyl cation, because equal amounts of substitution of nitrobenzene in the 3- and 4-positions are not typical for a homolytic aromatic substitution. 

The organic solvent is removed by distillation under reduced pressure to give 4,4 -dimethyl-l,T-biplienyl contaminated with a small amount of bis(4-methylphenyl)thallium bromide. The crude product is dissolved in 30 ml. of benzene, and the solution is filtered through a short column of alumina (Note 7) using a total of 250 ml. of benzene as eluent. Distillation of the benzene under reduced pressure leaves 19-21 g. (80-83%) of 4,4 -dimethyl 1,1 -biphenyl as a colorless solid, m.p. 118-120° (Note 8). 

Dimethyl-I,l -biphenyl has been prepared by a wide variety of procedures, but few of these are of any practical synthetic utility Classical radical biarjl syntheses such as the Gomberg reaction or the thermal decomposition of diaroyl peroxides give complex mixtures of products m which 4,4 dimethyl-l.l -biphenyl is a minor constituent A radical process maj also be involved in the formation of 4,4 dimethyl-1, l -biphenyl (13%) by treatment of 4-bromotoluene with hydrazine hydrate 5 4,4 -Dimethyl-l,l -biphenyl has been obtained in moderate to good yield (68-89%) by treatment of either dichlorobis(4-methyl phenyl)tellurium or l,l -tellurobis(4-methylbenzene) with degassed Raney nickel in 2 methoxyethyl ether 6... 

All of the useful procedures described for the preparation of 4,4 -dimethyl-1,l -biphenyl involve coupling of either a 4-halotoluene by a metal or the corresponding Gngnard reagents by a metal halide 4 Halotoluenes can be coupled directly by treatment with lithium,7 sodium,8 10 magnesium,11 oi copper12 13, yields are, however, very low in the first three cases (5-15%) and only moderate (54-60%) when... 

The present method of preparation of 4,4 -dimethyl-l,l -biphenyl is that described by McKillop, Elsom, and Taylor 15 It has the particular advantages of high yield and manipulative simplicity and is, moreover, applicable to the synthesis of a variety of symmetrically substituted biaryls 3,3 - and 4,4 -Disubstituted and 3,3, 4,4 -tetrasubstituted 1,1 -biphenyls are readily piepared, but the reaction fails when applied to the synthesis of 2,2 -disubstituted-l,T biphenyls The submitters have effected the following conversions by the above procedure (starting aromatic bromide, product biphenyl, % yield) bromobenzene, biphenyl, 85,1 -bromo-4-methoxybenzene, 4,4 -dimethoxy-l, 1 -biphenyl, 99, 1 bromo 3 methylbenzene, 3,3 dimethyl-1,l -biphenyl, 85 4-bromo-l,2-dimethylbenzene, 3,3, 4,4 -tetramethyl-l,l -biphenyl, 76, l-bromo-4-chlorobenzene, 4,4 -dichloro-l,l -biphenyl, 73, l-bromo-4-fluorobenzene, 4,4 -difluoro-l,l -biphenyl, 73... 

Related procedures, in which treatment of 4-methylphenylmagnes-mm halides with halides of copper(II),1,1 silver(I),17 cobalt(II),18 or chiomium(III)19 also lead to the formation of 4,4 -dimethyl-l,l -biphenyl, are either experimentally more difficult than, or do not give yields comparable to, the above method... 

Generally, higher catalyst concentration leads to side reactions. An efficient approach to minimize the side reactions is to use the minimum amounts of Friedel-Crafts catalyst (e.g., FeCl3, 0.1-4 wt%). The reaction can be performed either in bulk or in solution using, for example, nitrobenzene, dimethyl sulfone, or chlorinated biphenyls as the reaction media. 

Dimethylamino-methyl)-2-hydroxymethyl-aus 2 -Carboxy-2-(dimethylaminocarbonyl)-biphenyl und Lithiumalanat 165 2,2 -Dinitro- 474, 476, 695 6,6 -Dinitro-2,2 -bis-[chlorcarbonyl]- 188 2,2 -Dinitro-4,4 -bis-[diathylamino]- 695 4,4 -Dinitro-2,2 -bis-rhydroxymethyl]- 213 6,6 -Dinitro-2,2 -bis-[hydroxymethyl]- 188 2,2 -Dinitro-4,4 -diamino- 695 6,6 -Dinitro-2,2 -diformyl- 694 4,4 -Dinitro-2,2 -dimethoxycarbonyl- 213 2,2 -Dinitro-4,4 -dimethyl- 695 6,6 -Dinitro-2 -formyl-2-carboxy- 694 2,2 -Dinitroso- 476 -4-hydroxamsaure-chlorid 537 4-(a-Hydroxy-benzyl)- 542 Methoxy- 678 2-Methyl- 556 Nitro- 672, 678 4-Nitro- 687... 

CN 4 -[(l,4 -Dimethyl-2 -propyl[2,6 -bi-l//-benzimidazol]-l -yl)methyl][l,l -biphenyl]-2-carboxylic acid... 

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