4-Methyl-4 - biphenyls

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. 

The literature3 value for a carefully purified sample of 2-methyl-biphenyl is n2 1.5914. 

De la Mare et al.260 measured the rates of chlorination of biphenyl, a wide range of its methyl derivatives, and anisole in acetic acid at 25 °C. Second-order rate coefficients (104 2) were biphenyl (6.40), 2-methylbiphenyl (3.20), 3-methyl-biphenyl (820), 4-methylbiphenyl (30.0), 2.2 -dimethylbiphenyl (4.40), 3.3 -dimethylbiphenyl (2,630), 4,4 -dimethylbiphenyl (70.0), 2,6 -dimethylbiphenyl (1,130), 3,4,3, 4 -tetramethylbiphenyl (19,300), anisole (12.5 x 104), and these results showed very clearly the effect of steric inhibition of resonance between the phenyl rings through the presence of ortho methyl groups260. Similar (but rather more emphatic) results were obtained262 in chlorination of the /-butyl derivatives for which the corresponding rate coefficients were 2-/-butylbiphenyl (1.0) 4-/-butylbiphenyl (25.7), 2,2 -di-/-butylbiphenyl (1.8), 4,4 -di-/-butylbiphenyl (70.0). 

Capacitance and charge-transfer rates of SAM of ft)-(4 -methyl-biphenyl-4-yl)-alkanethiols (CH3—C6H4—C6H4—(CH2)n -SH, n = 0-6) adsorbed on pc-Au have also been investigated. For n = 1-6, the reciprocal capacity exhibited a linear dependence on the alkane spacer... 

A rough prediction of desorption and recovery can be made by extrapolation from similar compounds however, until we know more about the factors involved, this practice can lead to difficulties as illustrated in Table II. The recovery of naphthalene and biphenyl from charcoal are much lower than one would predict from the recoveries of other aromatic compounds, and this stronger attraction may be related to bond angles or steric effects. The order of recovery, ortho (84%) > meta (81%) > para (76%) methyl biphenyl, supports this theory. One may predict from this information that the recovery of benzene would be very poor, which is not the case. 

P entanitroanilino toluenes, C H NeO10, mw 408.24, N 20.59% were not found in Beil or CA through 1956. There is, however, PentQr nitro-N-methyUp-bipkenylamine, known also as N-Uetkyl-N,2,21,41,6-penttmitroxenyl-amine,which has the same empirical formula as above. This expl compd is described in this work under Methyl biphenyl amine and Derivatives... 

A solution of 2.0 g (6.9 mMol) of 2-n-propyl-5-(l-methylbenzimidazol-2-yl)-benzimidazole and 0.91 g (7.5 mmol) of potassium tert-butoxide in 50 ml of dimethylsulfoxide is stirred for 90 min at room temperature, then 2.6 g (7.5 mMol) of tert-butyl 4 -bromomethyl-biphenyl-2-carboxylate are added and the mixture is stirred for a further 15 h at room temperature. The mixture is then poured onto 300 ml of water and extracted three times with 50 ml of ethyl acetate. The crude product obtained after evaporation of the organic phase is purified by column chromatography (300 g silica gel eluant methylene chloride/methanol = 30 1). In this way, 2.7 g (70%) of an isomer mixture are obtained (by NMR spectroscopy), contains about 1.18 g of tert-butyl-4 -[(2-n-propyl-5-(l-methylbenzimidazol-2-yl)-benzimidazol-l-yl)-methyl]biphenyl-2-carboxylate and about 1.52 g of tert-butyl 4 -[(2-n-propyl-6-(l-methylbenzimidazol-2-yl)-benzimidazol-l-yl)-methyl]biphenyl-2-carboxylate). 

Fig. 4. Back electron transfer rates in photogenerated radical ion pairs in acetonitrile. In all cases cyanoanthracenes served as electron acceptors in their excited states, (a) Methylated benzene derivatives [60b] as donors (one-ring compounds), V = 11.5 cm"1, As = 1.63 eV. (b) Methylated biphenyls or naphthalenes [60b] as donors (two-ring compounds), V = 8.5 cm-1, /, = 1.48 eV. (c) Methylated phenanthrenes [60b] as donors (three-ring compounds) V = 8.0 cm-1, Xs = 1.40 eV. (dl Diphenylbutadienes [61] as donors, V = 8 cm-, X, = 1.55 eV. In all cases X, = 0.25 eV and V= 1500 cm-1...

Recently, the limitations for the intermolecular coupling have been significantly mitigated. Kawatsura and Hartwig [14] and Buchwald et al. [15] have demonstrated that aryl bromides and even aryl chlorides react with malonates (Eq. 3) and 1,3-diketones (Eq. 4) by using sterically bulky and electron-rich phosphines, such as P(f-Bu)3, D BPF, and 2-(di-ferf-butylphosphino)-2 -methyl-biphenyl, as ligands. 

C13H11CI 3-chloro-2-methyl biphenyl 20261-24-9 25.00 1.1370 1 25812 C13H1202 1-naphthalenepropanoic acid 3243-42-3 21.25 1.1359 2... 

C12H26 2-methyl-3-ethyl-3-isopropylhexane 62199-77-3 211.92 20.669 2 25739 C13H12 1-methyl biphenyl 28652-72-4 273.15 17.119 2... 

Open to the atmosphere, 4-bromoanisole (1.87 g, 10 mmol), o-tolylboronic acid (1.50 g, 11 mmol), KF (spray dried, dried in an oven overnight prior to use, 1.92 g, 33 mmol), and THF (10 mL) were added to a 100-ml round-bottomed Schlenk flask equipped with a stir bar. The reaction system was flushed with argon for about 5 min. P(t-Bu)3 (1.9 X 10 M stock solution in THF 2.31 mL, 5.0 x 10 mmol) and Pd2(dba)3 (2.16 x lO" M stock solution in THF 2.31 mL, 5.0 x 10 mmol) in THF were added sequentially. After 48 h at room temperature, the reaction mixture was diluted with ether or EtOAc, filtered through a pad of silica gel with copious washings, and then concentrated. The crude product was then purified via column chromatography eluting with 5% ether in hexane to yield 1.94 g (98%) of 4-methoxy-2 -methyl-biphenyl as a colorless liquid. 

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