589-93-5

Usage

Uses

Used in Pharmaceutical Industry:
2,5-Dimethylpyridine is used as an intermediate in the synthesis of various pharmaceutical compounds. Its ability to displace CO from the heme iron makes it a valuable component in the development of drugs targeting specific biological processes.
Used in Chemical Synthesis:
2,5-Dimethylpyridine is used as a reagent and catalyst in various chemical reactions, facilitating the formation of desired products and improving the efficiency of the synthesis process.
Used in Analytical Chemistry:
The FT-IR and FT-Raman spectra of 2,5-Lutidine have been studied, which indicates its potential use in analytical chemistry for the identification and characterization of compounds through spectral analysis.

Purification Methods

Steam distil the lutidine from a solution containing 1-2 equivalents of 20% H2SO4 until about 10% of the base has been carried over with the non-basic impurities, then the acidic solution is made alkaline, and the base is separated, dried with NaOH and fractionally distilled twice. Dry the distillate with Na and fractionally distil it through a Todd column (p 11) packed with glass helices. The hydrochloride has m 219o(dec), and the picrate has m 170.5o (from EtOH or H2O). [Beilstein 20 H 244, 20 II 160, 20 III/IV 2774, 20/6 V 27.]

InChI:InChI=1/C7H9N/c1-6-3-4-7(2)8-5-6/h3-5H,1-2H3

Upstream product

• 38203-08-6 5-methyl-2-pyridineacetonitrile 
• 83791-90-6 2,4-dichloro-3,6-dimethylpyridine 
• 67-56-1 methanol 
• 108-99-6 3-Methylpyridine 
• 546-67-8 lead(IV) tetraacetate 
• 64-19-7 acetic acid 
• 14435-92-8 carbonyl azide 
• 106-42-3 para-xylene 
• 110-86-1 pyridine 
• 109-06-8 α-picoline 
• 104-90-5 5-ethyl-2-methyl-pyridine 
• 100-97-0 hexamethylenetetramine 
• 123-63-7 paracetaldehyde 
• 50-00-0 formaldehyd 

Downstream Products

• 71858-91-8 2-(5-methyl-[2]pyridyl)-ethanol 
• 100975-46-0 2-(5-methyl-[2]pyridyl)-propane-1,3-diol 
• 7175-47-5 4-methylphenyl isocyanide 
• 114493-29-7 2-(4-cyclohexyl-phenyl)-6-methyl-indolizine 
• 7370-20-9 (E)-2-styryl-5-methylpyridine 
• 34893-50-0 2,5-dimethylpiperidine 
• 4985-92-6 5-methylpicolinaldehyde 
• 18113-81-0 2-ethyl-5-methylpyridine 
• 100-26-5 Pyridine-2,5-dicarboxylic acid 
• 5552-82-9 ethyl 2-(5-methylpyridin-2-yl)acetate 
• 27068-69-5 3,6-dimethyl-2-phenylpyridine 
• 107392-98-3 4-Hydroxy-3,6-dimethyl-2-phenylpyridine 
• 116037-22-0 2,5-Dimethyl-1-[2-oxo-3-(triphenyl-λ⁵-phosphanylidene)-propyl]-pyridinium; bromide 
• 141945-37-1 trans-2-<2-(2-chlorophenyl)vinyl>-5-methylpyridine 

Relevant academic research and scientific papers

Flow synthesis of 2-methylpyridines via α-methylation

A series of simple 2-methylpyridines were synthesized in an expedited and convenient manner using a simplified bench-top continuous flow setup. The reactions proceeded with a high degree of selectivity, producing α-methylated pyridines in a much greener fashion than is possible using conventional batch reaction protocols. Eight 2-methylated pyridines were produced by progressing starting material through a column packed with Raney nickel using a low boiling point alcohol (1-propanol) at high temperature. Simple collection and removal of the solvent gave products in very good yields that were suitable for further use without additional work-up or purification. Overall, this continuous flow method represents a synthetically useful protocol that is superior to batch processes in terms of shorter reaction times, increased safety, avoidance of work-up procedures, and reduced waste. A brief discussion of the possible mechanism(s) of the reaction is also presented which involves heterogeneous catalysis and/or a Ladenberg rearrangement, with the proposed methyl source as C1 of the primary alcohol.

Generation and reactions of pyridyllithiums via Br/li exchange reactions using continuous flow microreactor systems

A continuous flow microreactor method for generating and carrying out reactions on pyridyllithiums has been developed based on Br/Li exchange reactions of bromopyridines and dibromopyridines. The reactions can be carried out without using cryogenic conditions by virtue of short residence times and efficient heat transfer, while very low temperatures such as-78 or-110°C are required for conventional batch macro methods. Moreover, sequential introduction of two different electrophiles has been successfully achieved using dibromopyridines in an integrated flow microreactor system composed of four micromixers and four microtube reactors.

Convenient procedure for the α-methylation of simple pyridines

A convenient and straightforward laboratory procedure is presented for a highly selective mono-α-methylation of pyridines without reactive functional groups. The methylating agent is probably carbon monoxide/dihydrogen generated in situ from a high-boiling alcohol on a metal surface. The reaction is catalyzed by a Raney nickel catalyst at ambient pressure, which renders the protocol practicable in standard organic laboratories. The intrinsically high reaction temperature and long reaction times restrict the application to pyridine derivatives with less reactive substituents. The outcome of the reaction can be rationalized by the assumption of a simple heterogeneous mechanism. Copyright Taylor & Francis Group, LLC.

Titanocene(III) catalyzed homogeneous hydrosilation-hydrogenation of pyridines

The homogeneous catalytic hydrosilation-hydrogenation of pyridines is observed in the presence of Cp2TiMe2 (Cp = η5-C5H5) and CpCp*TiMe2 (Cp* = η5-C5Me5) as catalysts and using PhSiH3 or PhMeSiH2 as the source of Si-H. Under appropriate conditions, and with appropriate ring-substitution, good yields of the N-silyldihydropyridine or N-silyltetrahydropyridine products are be obtained. Although complete saturation is not achieved with organosilane alone, carrying out the reaction under moderate H2 pressures can give excellent yields of N-silylpiperidines. Under moderate pressures of H2, [Cp2TiH]2 catalyzes rapid H-D exchange between H2 and the 2- and 6-positions of C5D5N. Under the same conditions, only traces of hydrogenation are observed. This, together with the regioselectivity of 3-picoline hydrosilation-hydrogenation, leads to the conclusion that the key step in the reaction is probably addition of Ti-Si to C=N.

Vapor-phase photochemistry of dimethylpyridines

Irradiation of dimethylpyridine vapors (2-5 Torr) at 254 nm results in the formation of two sets of isomerization products. One set, formed in the larger yield, is substantially quenched when the irradiations are carried out in the presence of 15-21 Torr of nitrogen and is not formed when the irradiations are carried out with light of λ > 290 nm. In addition, a second set of reactions, which involve the interconversion of 2,3- and 2,5- dimethylpyridines, is enhanced by the addition of nitrogen, and these reactions are the only photoisomerization reactions observed when the irradiations are carried out with light of λ > 290 nm. In addition to the photoisomerizations, four of the dimethylpyridines also undergo demethylation to yield monomethylpyridines, and 2,6-dimethylpyridine undergoes methylation to yield a trimethylpyridine product. A variety of crossover experiments confirmed that the photoisomerizations are intramolecular. Based on the major phototransposition products, the six dimethylpyridines can be divided into two triads. Interconversion of the three members of each triad results in the major phototransposition products. These intra-triad interconversions are suggested to occur via 2,6-bonding, originating in a vibrationally excited S2 (π,π*) state of the dimethylpyridine, followed by nitrogen migration and rearomatization. This allows nitrogen to insert within each carbon- carbon bond. Phototransposition of 2,6-dideuterio-3,5-dimethylpyridine to a mixture of 5,6-dideuterio-2,4-dimethylpyridine and 3,4-dideuterio-2,5- dimethylpyridine is consistent with this mechanism. In addition to these intra-triad reactions, 2,5-dimethylpyridine, a member of triad 1, was observed to interconvert with 2,3-dimethylpyridine, a member of triad 2. These inter-triad reactions are suggested to occur via interconverting Dewar pyridine intermediates, formed from the triplet state of the dimethylpyridines. These Dewar pyridine intermediates were also observed by 1H NMR spectroscopy after irradiation of the dimethylpyridines in CD3CN at -30 °C.

SIMPLE AND CONVENIENT DEOXYGENATION OF HETEROAROMATIC N-OXIDES WITH SODIUM HYPOPHOSPHITE

Sodium hypophosphite catalytic transfer hydrogenation in the presence of 10percent palladium on carbon constitutes a simple and excellent deoxygenation method for heteroaromatic N-oxides in acetic acid medium.

SIMPLE AND EFFICIENT DEOXYGENATION OF HETEROAROMATIC N-OXIDES USING TiCl4/SnCl2.

Various unfunctionalized heteroaromatic N-oxides are efficiently deoxygenated to the corresponding bases under mild conditions by treatment with the novel reagent TiCl4/SnCl2.

An Improved Liquid-Phase Synthesis of Simle Alkylpyridines

The synthesis of pyridines from mixtures of aldehydes or ketones and NH3 in the liquid phase has been reinvestigated, using continuous dosage of the carbonyl components to the reaction mixture.The main product from the reaction of acetaldehyde and formaldehyde is 3-methylpyridine (6), which is also the main product from the reaction of acrolein or a mixture of crotonaldehyde and formaldehyde under the same conditions.The reaction of other aldehydes with formaldehyde give 3,5-dialkylpyridines, e.g. 10, 16.Acetone reacts with either formaldehyde or acetaldehyde to give polysubstituted alkylpyridines.A mechanistic pathway is proposed which accounts for the formation of the observed products.

Transformations of pyridine bases on a nickel-aluminum catalyst

The electronic structures of some pyridine bases are analyzed by means of 1H and 13C NMR spectroscopic data for substituted pyridines and the calculated bond orders in the pyridine ring. The differences in the chemical bonds in the pyridine ring of isomeric methylpyridines and the carbon-carbon bonds between the ring and the methyl groups in these compounds are in agreement with the experimental data on the thermal stability of the simplest pyridine bases and the gas-phase transformation of the isomeric methylpyridines on an industrial nickel-aluminum catalyst. The possibility of obtaining mono- or dialkylpyridines under these conditions, depending on the structure of the starting pyridine bases, is demonstrated.