2.5- Dimethyl-6-phenylpyridine

More recently, analogs of 20 and 21 have been prepared in a similar manner from 2,5-dimethyl-4-phenylpyridine and the same cyclization has also been effected using formamide instead of acetic anhydride.47... 

Dimethyl-4-phenylpyridine undergoes nitration using mixed acid at 0°C (1 h) to form 25% of the 4-nitrophenyI product and 35% of a dinitro product, which has not been characterized. The corresponding acid (63,R = C02H) gives the 3-nitrophenyl product (60%) (76CHE312). 

Abbreviations AD, asymmetric dihydroxylation BPY, 2,2 -bipyridine DMTACN, 1,4-dimethyl-l,4,7-triazacyclonane EBHP, ethylbenzene hydroperoxide ee, enantiomeric excess HAP, hydroxyapatite LDH, layered double hydroxide or hydrotalcite-type structure mCPBA, meta-chloroperbenzoic acid MTO, methyltrioxorhenium NMO, A-methylmorpholine-A-oxide OMS, octahedral molecular sieve Pc, phthalocyanine phen, 1,10-phenantroline PILC, pillared clay PBI, polybenzimidazole PI, polyimide Por, porphyrin PPNO, 4-phenylpyridine-A-oxide PS, polystyrene PVP, polyvinylpyridine SLPC, supported liquid-phase catalysis f-BuOOH, tertiary butylhydroperoxide TEMPO, 2,2,6,6-tetramethyl-l-piperdinyloxy TEOS, tetraethoxysilane TS-1, titanium silicalite 1 XPS, X-ray photoelectron spectroscopy. 

Trp-P-1 3-amino-1,4-dimethyl-5//-pyrido[4,3-fe]indole Trp-P-2 3-amino-l-methyl-5//-pyrido[4,3-fe]indole Glu-P-1 2-amino-6-methyldipyrido[l,2-a 3, 2 -ct]imidazole Glu-P-2 2-aminodipyrido[ 1,2-a 3, 2 -rf]imidazole Phe-P-1 2-amino-5-phenylpyridine... 

Heating 3-benzamido-2,6-dimethyl-A-phenylpyridine-4-carboxamide at 200 =C for 12 hours gives a 100% yield of 6,8-dimethyl-2,3-diphenylpyrido[3,4-d]pyrimidin-4(3i7)-one.453... 

Ouweland et al., 1978) or directly by the pyrolysis of amino acids (Fujimaki et al., 1969). Another important, if not the main, precursor of pyridines in roasted coffee is trigonelline (see Section 2.1.1.2), a product isolated by Goi ter (1910), identical to the product isolated from the seeds of Trigonella foenum-graecum. Viani and Horman (1974, 1976) identified 12 pyridinic compounds after pyrolysis of trigonelline, six of which have now been identified in roasted coffee (4-methylpyridine is noted as identified in coffee, but it is not present in the lists of quoted publications, and to our knowledge its identification has not yet been reported in the literature). The presence of four other alkyl derivatives and of two N-methylnicotinamides have not yet been confirmed in the flavor. The authors have also isolated two piperidylpyridines, 3-phenylpyridine and two of its methyl derivatives, as well as four unsubstituted and dimethyl-substituted dipyridyl compounds. 

Benzaldehyde, methyl propiolate, NH4-acetate, and acetic acid heated 10-15 min. on a steam bath dimethyl l,4-dihydro-4-phenylpyridine-3,5-dicarboxylate. Y 79%. F. e. s. T. Chennat and U. Eisner, Soc. Perkin I 1975, 926. 

In the derivatives of 2-phenylpyridine platinum compounds 9.15, as shown in Eq. (9.5), cytotoxicity was also studied in three human cancer cell lines derived from ovarian carcinoma (CHI), lung carcinoma (A549), and colon carcinoma (SW480) by means of an MTT assay (MTT=3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) [74]. This study needs to be pursued further in future, however, in order to be able to find the role of different phosphine ligands in this field. 

Dimethyl-4-phenylpyridine was produced using an analogous sequence and this process has expanded the access to a variety of 2,4,6-substituted pyridines. This synthetic sequence had limited utility however, due to the reactivity of the intermediate pyrylium ions with residual organomagnesium reagents during the quench. 

When 2,5-dimethyl-4-phenylpyridine is heated with sodium amide at 180° for 5 hours, 2-amino-3,6-dimethyl-4-phenylpyridine (IX-8) is obtained. If the 2-and 6-positions are not available, direct amination takes place at the 4-position thus, the reaction of 2,6-lutidine with sodium in liquid ammonia yields 4-amino-2,6-lutidine (IX-9). The 4-chloro substituent in perchloropyridine is... 

Huisgen and Herbig condensed A -benzylphenylazomethine (X-18) with two moles of dimethyl acetylenedicarboxylate to obtain the corresponding 1,2-dihydropyridinetetracarboxylic acid ester (X-19). Oxidation with bromine afforded tetramethyl 2-phenylpyridine 3,4,5,6-tetracarboxylate (X-20). 

CigHigNsOS, 2-Formyl-4-phenylpyridine thiosemicarbazone - dimethyl-formamide, 43B, 305 CigH2o iiC3S, Torasemide, 44B, 218... 

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