Pyridine, methylation

The ease with which dissolution of the acetylated products can be achieved is affected by the method of isolation. In the author s experience, drying of the acetate with alcohol and ether results in apparent insolubility (even though the product was soluble at one stage of the purification process), and should be avoided. Drying, under diminished pressure, of the product precipitated by petroleum ether is sufficient. Chloroform is probably the best solvent. Nitroethane, tetrachlorethane, 2,4-pentanedione, pyridine, methyl acetate, ethyl acetate, and benzene, which have also been suggested, have disadvantages in that either they are unstable or they may cause aggregation in solution.44,116 116... 

On unimolar benzoylation with the acid chloride in pyridine, methyl a-1> I yxopy ran os i de gave the 3-benzoate in 46% yield,71 a result that might have been expected in view of the course oi selec-... 

Uses Microscopy medicine testing for pyridine methylating agent. 

Aromatic N-containing heterocycles (pyridine, imidazole etc.,) and their alkyl derivatives represent an important group of products and they have received considerable attention because of their various applications. For instance, methyl pyridines (picolines) and dimethyl pyridines (lutidines) are a class of industrially valuable compounds for the production of dyes and fine chemicals [108]. Sreekumar et al [109] reported pyridine methylation to 3-picolines over Zni xCoxFe204 spinel systems at reaction temperature between 325 and 425°C. The... 

Zni xCuxFe204 have been examined for pyridine methylation with methanol at vapor phase conditions [111]. The conversion of pyridine as well as yield to 3-methyl pyridine is found to be lowest in the case of ZnFe204, whereas conversion and selectivity increases as the copper content is increased and is maximum for x = 1 composition. 

Several standard reactions have been applied to substituents in 2,2 -bi-pyridines. Methyl-substituted 2,2 -bipyridines are oxidized to the corre-... 

On treatment with camphorsulfonic acid/pyridine, methyl ( )-1-[(.S )-4-mcthylphcnylsuirinyl]-2-alkenoates undergo, enantioselectively, a sequential prototropic shift and allylic sulfoxide/ sulfenate rearrangement to produce methyl (R,/f)-4-hydroxy-2-alkcnoates in 64- 72% optical purity63a. 

Imidazo[4,5-b pyridines. Methyl chloride reacts with 78 at the nitrogen atom of the pyridine ring, but with 79 at the unsubstituted imidazole nitrogen atom.183 The Former result is surprising because it does not fit a prediction based on a consideration of the relative reactivities of pyridine and 1-methylimidazole.44... 

Reaction of 2-S-S-bis(5-methoxybenzimidazole) 1 with 3,5-dimethyl-4-methoxy-2-pyridine methyl carboxylate 2 followed by reaction with ammonia to give the carboxylate thioether 3. Compound 3 was oxidized to give the carboxylate sulfoxide 4 which was decarboxylated to give omeprazole 5. 

Malhotra, B.D., Pethrick, R.A (1985) Positron annihilation in 4-vinyl pyridine methyl methacrylate copolymer . Poly. Comm. 26,14. 

Tobacco smoke contains both particulate matter (see Chapter 4) and a large number of gaseous and vapor components. These components include CO, CO2, NO, NO2, acrolein, pyridine, methyl chloride, acetaldehyde, formaldehyde, and dimethylnitrosamine. Particulate matter comprises, for example, nicotine, pyrene, benzo( )pyrene, naphthalene, methyl naphthalene, aniline, and ni-trosonomicotine. 

Kosower and Teuerstein showed that o-xylylene bis-pyridinyl and 1,8-biphenyl-ene bis-pyridinyl diradicals could be photolyzed in low quantum yields at 400 nm to yield the corresponding pyridine (methyl isonicotinate) and either a carbomethoxy-azaanthracene or 1,8-dimethylbiphenylene (Eqs. 22). 

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