Pyridine, 2,6-diphenyl

Moreover, the group explored Sonogashira, Suzuki and Stille couplings of 25, where the reactivity of the C-Cl and C-Br bonds was shown to be similar. Scheme 8 illustrates an example of the Stille reaction accomplished with compound 25 yielding 2,5-diphenyl pyridine 28. 

Die sterischen Verhaltnisse konnen die Selektivitat jedoch verandem 2,6-Diphenyl-pyridin liefert als Hydrochlorid in Athanol mit Platin(IV)-oxid 2,6-Dicyclohexyl-piperi-din, und die 2,4,6-Triphenyl-Verbindung ergibt 2,4,6-Tricyclohexyl-pyridin1. 

Fig. 7.16. Facial selectivity of diphenyl pyridine-te-oxazoline catalysts. Reproduced from Tetrahedron Asymmentry, 9, 357 (1998), by permission of Elsevier.

The crystal structure of the 2,6-diphenyl pyridine complex 19 shows a 0 interaction between the C-H bond and the coordination site trans to Ir-C (Eq. 2.25)... 

Metho. 2.6-diphenyl-pyridin-dicarbon< aaure-(3.S)-di tliyle8ter 22, 274. 

Phosphonate ester or phosphonic acid substituents have been additionally evaluated in an attempt to increase the interacting sites with the phosphoric acid doping agent along the polyelectrolyte macromolecular chains. These were strategically located as side groups in a diol monomer which was prepared by a phosphoms-carbon coupling reaction of tetrahydropyranyloxy diprotected 2,5-dibromo-1,4-dihydroxy benzene with diethylphosphite. Either in the phosphonate ester or in the phosphonic acid form the diol was used in polymerizations with the bis (4-fluorophenyl) sulfone or bis(4-fluorophenyl) phenylphosphinoxide as well as with the 2,5-diphenyl-pyridine diol and the tetramethyl-... 

Diphenyl (pyridin-3-yl(p-tolylamino)methyl) phosphonate (4d) White solid, mp 194-196 °C reaction time 32 h yield 89%... 

The historical direct reaction route, which utilised phosgenation of a solution of BPA in pyridine, proved inefficient commercially because of the need for massive pyridine recycle. Calcium hydroxide was used as an HCl scavenger for a period of time. In the historical transesterification process, BPA and diphenyl carbonate are heated in the melt in the presence of a catalyst, driving off by-product phenol, which is recycled to diphenyl carbonate. Using a series of reactors providing higher heat and vacuum, the product polymer was eventually produced as a neat melt. 

Imidazo[4,5-6]pyridine, 1,2-dimethyl-methylation, 5, 618 Imidazo[4,5-6]pyridine, 2,3-diphenyl-synthesis, 5, 636 Imidazo[4,5-6]pyridine, 6-halo-alkylation, 5, 616 aminomethylation, 5, 616 Imidazo[4,5-6]pyridine, 2-(4-hydroxy-6-methylpyrimidin-2-ylamino)-synthesis, 5, 637... 

Pyridine, 2-(dimethylamino)-5-nitro-nitration, 2, 189 Pyridine, 3,5-dinitro-conformation, 2, 110 Pyridine, 3,5-diphenyl-synthesis, 2, 0... 

Most N-phenyl quaternary salts are not prepared by direct quater-nization but rather by introducing the nitrogen substituent before ring closure. It has recently been found that diphenyl iodonium boro-fluoride reacts smoothly with pyridine the phenyl carbonium ions formed give the 1-phenylpyridinium ion good yield. ... 

Tile same methodology as mentioned for the preparation of (9) was applied for the synthesis of 8-nitro-l,6-naphthyridines. Heating diethyl N- 3-nitropyridin-4-yl)aminomethylenemalonate (12) in diphenyl ether yields ethyl 8-nitro-l,6-naphthyridin-4(lH)-one 3-carboxylate (13) (63JCS4237, 30%) and acid treatment of 4-( y, y-diethoxypropylamino)-5-nitro-2-(/3,/3 -trifluoroethoxy)-pyridine (14) gives in a similar way 8-nitro-5-(/3, /3-triflu-oroethoxy)-l,2-dihydro-l,6-naphthyridine (15, 76%). Subsequent oxidation with chloranil, acid hydrolysis, and methylation with methyl iodide gives 8-nitro-6-methyl-l,6-naphthyridin-5(6H)-one (16,63%) (81JHC941). 

Another approach involves utilization of the amines for addition of a fused pyridine ring to the benzothiadiazole skeleton. The Gould-Jacobs reaction of 4-amino-2,l,3-benzothiadiazole 60 with diethyl ethoxymethylenemalonate gave the substitution product, and, after thermal cyclization in diphenyl ether, afforded the... 

Abbreviations acac, acetylacetonate Aik, alkyl AN, acetonitrile bpy, 2,2 -bipyridine Bu, butyl cod, 1,5- or 1,4-cyclooctadiene coe, cyclooctene cot, cyclooctatetraene Cp, cyclopentadienyl Cp, pentamethylcyclopenladienyl Cy, cyclohexyl dme, 1,2-dimethoxyethane dpe, bis(diphenyl-phosphino)ethane dppen, cis-l,2-bis(di[Atenylphosphino)ethylene dppm, bis(diphenylphosphino) methane dppp, l,3-bis(diphenylphosphino)propane eda,ethylenediamine Et,ethyl Hal,halide Hpz, pyrazole HPz, variously substituted pyrazoles Hpz, 3,5-dimethylpyrazole Me, methyl Mes, mesityl nbd, notboma-2,5-diene OBor, (lS)-endo-(-)-bomoxy Ph, phenyl phen, LlO-phenanthroline Pr, f opyl py, pyridine pz, pyrazolate Pz, variously substituted pyrazolates pz, 3,5-dimethylpyrazolate solv, solvent tfb, tetrafluorobenzo(5,6]bicyclo(2.2.2]octa-2,5,7-triene (tetrafluorobenzobanelene) THE, tetrahydrofuran tht, tetrahydrothicphene Tol, tolyl. 

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