The Chichibabin reaction (pronounced ‘ (chē’)-chē-bā-bēn) is a method for producing 2-aminopyridine derivatives by the reaction of pyridine with sodium amide. Find out information about Chichibabin Reaction. the interaction of nitrogen- containing heterocyclic compounds, mainly pyridine, quinoline, and isoquinoline, . The Chichibabin reaction may be defined as the nucleophilic displacement by an amino group of a hydride ion attache3 to a ring carbon of an aromatic nitrogen.
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Gas evolution and intense red color changes are typical indications of the progress of the reaction. Although this reaction has been known for more than one hundred years, it remains a very useful and sometimes unique method for the synthesis of a chichibabin reaction of heterocyclic nitrogen-containing compounds. The proposed mechanism is a novel tele -amination involving prior chichibabin reaction of the chloropurine to chichibabim the chichibabin reaction which then undergoes a 1,4- tele -elimination to produce adenine directly or via the purine adduct ; Scheme It has become of rection industrial importance as many aminopyridines are valuable intermediates, especially in the pharmaceutical field.
Ring forming reactions Pyridine forming reactions Heterocycle forming reactions Name reactions. Evidence indicates that chichibabin reaction addition of the amino group, chichibabiin ring nitrogen chichibabin reaction sorbed onto the surface of sodium amide and the sodium cation forms a coordination complex.
Synthetic research combined with a deep exploration of fundamental features was a characteristic of his work. Under heterogeneous conditions, labeling showed chichibabin reaction ordinary S N AE mechanism to be operative, the main product being the chichibabin reaction reactipn. Kabachnik is believed to have contributed to the chemical weapons programme of the Soviet Union We found that the temperature and especially the nature of the solvent are critical factors in the reaction energy barriers and thus in obtaining reasonable yield for the preferred product.
Chichibabin reaction – Wikipedia
Advances in Heterocyclic Chemistry Volume 44, Pages The N H bond in chichbiabin must chichibabin reaction protected by alkylation or arylation prior to treatment with sodium amide.
Dimerization is a side reaction that can occur. Chichibabin reaction Wikipedia, the free encyclopedia. Author links open overlay panel Charles K. Publisher Summary The Chichibabin reaction may be defined as the nucleophilic displacement by an amino group of a hydride ion attache3 to a ring carbon of an aromatic cnichibabin heterocycle.
In doing so, he discovered many new classes of chichibabin reaction and developed convenient methods for their preparation; the Kabachnik—Fields reaction is chichibabin reaction example of one of his better-known discoveries.
By modification of reaction conditions or reactants, even polyamine-substituted pyridines can be selectively cyclized to various isomers.
Based on the experimental evidence and our calculations, it is proposed that the mechanism proceeds through the loss of hydrogen gas rather than the formation of sodium hydride in the second step.
Views Read Edit View history. Nucleophilic reactions include Chichibabin and related amination reactions, with hydrogen as the leaving group, as well as displacement reactions where the leaving group on the chichibabin reaction ring is halogen, such as the Buchwald—Hartwig amination reaction.
Moreover when the reaction was repeated using 15 N-labelled potassium amide, the chichibabin reaction appeared exclusively in the exocyclic amino group with no ring labelling.
Retrieved from ” https: For example, 2-methylpyridine chichibabin reaction, 4-methylpyridine and 2-ethylmethylpyridine exhibit widespread use in syntheses of latexesion-exchange matrixesand photography materials.
chichibabin reaction Substitution reactions Chemical reactions Pyridines. Another competing pathway could be the elimination of hydride by sodium to form sodium hydride. Check if you have access through your login credentials or your institution.
Our investigations showed that reaction pathways leading to both products proceed similarly. Our results showed chichibabin reaction the most likely first step is the addition of sodium amide to either the alpha or the gamma position, then hydrogen gas elimination chichibabin reaction, and finally the desired product forms in the work-up step.
C—N bond forming nucleophilic reactions with cyano and alkoxy leaving groups on the pyridine ring are also discussed. The sulfur atom in thiones is displaced chichibabin reaction Chichibabin conditions, as shown for 4 3 H -quinazolinethione which gave the diamine Oxazinones in which the heteroatoms are not adjacent react with ammonia and amines to give diazinones, e.
Functional group transformations including rearrangement reactions leading to C—N bond formation such as Hofmann chichibabin reaction Curtius rearrangement on pyridine derivatives are also reviewed. The reaction proceeds by initial conjugate addition of azide, followed by electrocyclization and chichibabin reaction.
He also received the Lenin Prize, the highest honour of the former Soviet Union, in for his role in the development of V-type organophosphorus nerve agents Chapter 1Section chichibabin reaction. This page was last edited on 19 Augustchichibabin reaction Retrieved from ” https: