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4-Methylpyridine is the organic compound with the formula CH 3 C 5 H 4 N. It is one of the three isomers of methylpyridine. This pungent liquid is a building block for the synthesis of other heterocyclic compounds. Its conjugate acid, the 4-methylpyridinium ion, has a pK a of 5.98, about 0.7 units above that of pyridine itself. [1]
The Chichibabin pyridine synthesis (/ ˈ tʃ iː tʃ iː ˌ b eɪ b iː n /) is a method for synthesizing pyridine rings. The reaction involves the condensation reaction of aldehydes , ketones , α,β-Unsaturated carbonyl compounds , or any combination of the above, with ammonia . [ 1 ]
[4] σ-adduct (Meisenheimer adduct) formation; Evidence indicates that before addition of the amino group, the ring nitrogen atom is sorbed onto the surface of sodium amide and the sodium cation forms a coordination complex. [3] This increases the δ+ on the α-carbon atom, thus 1,2-addition of sodium amide is favored over 1,4-addition.
This was the first synthesis of a heteroaromatic compound. [24] [40] The first major synthesis of pyridine derivatives was described in 1881 by Arthur Rudolf Hantzsch. [41] The Hantzsch pyridine synthesis typically uses a 2:1:1 mixture of a β-keto acid (often acetoacetate), an aldehyde (often formaldehyde), and ammonia or its salt as the ...
trans-[MCl 2 (pyridine) 4] n+ is a common type of transition metal pyridine complex. Chloro(pyridine)cobaloxime. Crabtree's catalyst.. Owing to the relatively wide C-N-C angle, the 2,6-hydrogen atoms interfere with the formation of [M(py) 6] z complexes.
DNA and RNA also contain other (non-primary) bases that have been modified after the nucleic acid chain has been formed. In DNA, the most common modified base is 5-methylcytosine (m 5 C). In RNA, there are many modified bases, including those contained in the nucleosides pseudouridine (Ψ), dihydrouridine (D), inosine (I), and 7-methylguanosine ...
Another use of the Kröhnke pyridine synthesis was the generation of a number of 2,4,6-trisubstituted pyridines that were investigated as potential topoisomerase 1 inhibitors. [ 20 ] 2-acetylthiophene ( 46 ) was treated with iodine and pyridine to generate α-pyridinium acyl ketone 47 .
3-Methylpyridine or 3-picoline, is an organic compound with formula 3-CH 3 C 5 H 4 N. It is one of three positional isomers of methylpyridine, whose structures vary according to where the methyl group is attached around the pyridine ring. This colorless liquid is a precursor to pyridine derivatives that have applications in the pharmaceutical ...