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4-Methylpyridine is both isolated from coal tar and is synthesized industrially. It forms via the reaction of acetaldehyde and ammonia in the presence of an oxide catalyst. The method also affords some 2-methylpyridine. 4-Methylpyridine is of little intrinsic value but is a precursor to other commercially significant species, often of medicinal ...
3-Methylpyridine degrades more slowly than the other two isomers, likely due to the impact of resonance in the heterocyclic ring. Like most simple pyridine derivatives, the picolines contain more nitrogen than is needed for growth of microorganisms, and excess nitrogen is generally excreted to the environment as ammonium during the degradation ...
2-Methylpyridine, or 2-picoline, is the compound described with formula C 6 H 7 N. 2-Picoline is a colorless liquid that has an unpleasant odor similar to pyridine. It is mainly used to make vinylpyridine and the agrichemical nitrapyrin .
A trihydrate (pyridine·3H 2 O) is known; it also crystallizes in an orthorhombic system in the space group Pbca, lattice parameters a = 1244 pm, b = 1783 pm, c = 679 pm and eight formula units per unit cell (measured at 223 K).
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 ...
Geography is a branch of inquiry that focuses on spatial information on Earth. It is an extremely broad topic and can be broken down multiple ways. [14] There have been several approaches to doing this spanning at least several centuries, including "four traditions of geography" and into distinct branches.
A portion of tetrapod workers, led by French paleontologist Michel Laurin, prefer to restrict the definition of tetrapod to the crown group. [14] [18] A crown group is a subset of a category of animal defined by the most recent common ancestor of living representatives. This cladistic approach defines "tetrapods" as the nearest common ancestor ...
This glossary of geography terms is a list of definitions of terms and concepts used in geography and related fields, including Earth science, oceanography, cartography, and human geography, as well as those describing spatial dimension, topographical features, natural resources, and the collection, analysis, and visualization of geographic ...