4,4’-Difluoro biphenyl

In some molecules the molecular dipole is simply dominated by a single polar bond. In sufficiently complex molecules there may be several polar bonds of differing strength. In this case the molecular dipole is determined by their relative orientation. Ab initio studies of 2-2 -difluoro biphenyl have revealed a strong shape dependence of the molecular dipole as a function of inter-ring angle. This is illustrated in Fig. 12. 

Fig. 12. Torsional potential and molecular dipole for 22-difluoro biphenyl...

Diflu-oro-a-methyl-y-oxo-(1,1 -bi-phenyl)-4-butanoic acid, 4-(2, 4 -Difluoro-biphenyl-4-yl)-2-methyl-4-oxo-butyric acid C17H14F203, Mr 304.29... 

Comparison of the four molecules biphenyl, 2-fluorobiphenyl, 2,2 -difluoro-biphenyl and perfluorobiphenyl shows that the angle of twist increases in a reasonable way introducing more fluorine atoms in the 2-position (Table 6). A twist angle recently reported for crystalline 2-H-nonafluorobiphenyl237 of 59.5 0 also fits nicely into the picture. 

For systemic use, 3-chloro-2, 4 -difluoro-biphenyl-4-carbonitrile, is especially preferred. For topical application, 3-chloro-2, 6 -difluoro-biphenyl-4-carbonitrile is preferred. 

Although most applications use smecto-gens of positive dielectric anisotropy, there are some wide temperature range smecto-gens of negative dielectric anisotropy. Some notable examples are the lateral cyano phenyl benzoates [18] (6) and the 2,3-difluoro-biphenyl carboxylic acid esters [19], e.g.. 

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... 

An early biphenyl candidate, A-331440 (6) has been reported to be a competitive, potent inverse agonist with balanced activity at human and rat H3Rs with good oral bioavailability [40]. While A-331440 was active in obesity models, its development was precluded by genotoxicity issues [41], The latter was eliminated by a tactical orf/zo-substitution on the phenoxy central core by fluorine to provide A-417022 (7). A-417022 and the 3,5-difluoro analog (A-423579) also produced prolonged weight loss over a 28-day period in a rat diet-induced obesity model [17,41],... 

Chemical Name 2, 4 -Difluoro-4-hydroxy-[l,l -biphenyl]-3-carboxylic acid... 

SYNS DIFLUNISAL 2, 4 -DIFLUORO-4-HYDROXY-(l,l -BIPHENYL)-3-CARBOXYLIC ACID 2, 4 -DIFLUORO-4-HYDROXY-3-BIPHENYLCARBOXYUC ACID 2, 4 -DIFLUORO-4-HYDROXY-(l, l-DIPHENYL)-3-CARBOXYLIC ACID DOLOBID DOLOBIL DOLOBIS FLOVACIL FLUNIGET 2-(HYDROXY)-5-(2,4-DIFLUOROPHENYL)BENZOIC ACID MK 647... 

Physical constants of several partially fluorinated biphenyls (up to the 2,2, 3,4, -5,5, 6-heptafluoro-compound), obtained by a range of classical methods including the Friedel-Crafts, Ullmann, and Balz-Schiemann reactions, have been reported, and 1,8-difluoro- or 1,4,5-trifluoronaphthalene may be obtained by conventional routes (nitration, reduction, diazotization) from 1,8-diamino- or 1,5-difluoro-naphthalene, respectively. ... 

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