87378-58-3Relevant academic research and scientific papers
Fluorocarbon Derivatives of Nitrogen. Part 13. Reaction of Perfluoroalkanenitriles with Pyridinium Alkoxycarbonylmethylides: Synthesis of Perfluoroalkylated Imidazopyridines (1-Azaindolizines). X-Ray Molecular Structure of Pyridinium 4,5-Dihydro-4-oxo-2,6-bis(trifluoromethyl)py...
Banks, Ronald E.,Pritchard, Robin G.,Thomson, Julie
, p. 1769 - 1776 (2007/10/02)
Pyridinium t-butoxycarbonylmethylide, generated in situ by treatment of N-(t-butoxycarbonylmethyl)pyridinium perchlorate with sodium hydride (in acetonitrile) or triethylamine (in dichloromethane), reacts with trifluoroacetonitrile to yield 3-(t-butoxycarbonyl)-2-(trifluoromethyl)imidazopyridine, N-pyridinium perchlorate, and pyridinium 4,5-dihydro-4-oxo-2,6-bis(trifluoromethyl)pyrimidin-5-ylide.The corresponding heptafluoropropyl compounds can be prepared in the same way, starting from heptafluorobutyronitrile; in both cases, the relative yields of the three types of product can be varied by changing the reactant ratios.Treatment of N-pyridinium perchloroate with heptafluorobutyronitrile in the presence of triethylamine gives 2-(heptafluoropropyl)-4,5-dihydro-4-oxo-6-(trifluoromethyl)pyrimidin-5-ylide.Trapping of pyridinium ethoxycarbonylmethylide with trifluoroacetonitrile provides the known 3-(ethoxycarbonyl)-2-(trifluoromethyl)imidazopyridine, plus pyridinium 4,5-dihydro-4-oxo-2,6-bistrifluoromethyl)pyrimidin-5-ylide.Reduction (zinc-acetic acid) of the latter, for which a detailed X-ray crystallographic analysis has been performed, gave 4-hydroxy-2,6-bis(trifluoromethyl)pyrimidine.A stepwise mechanism is proposed to account for the cycloaddition step involved in formation of perfluoroalkylated imidazopyridines form pyridinium alkoxycarbonylmethylides and the perfluoroalkanenitriles CF3CN and n-C3F7CN.
Reaction of Pyridinium t-Butoxycarbonylmethylide with Trifluoroacetonitrile
Banks, Ronald Eric,Thomson, Julie
, p. 589 - 592 (2007/10/02)
Pyridinium t-butoxycarbonylmethylide (I), generated by treatment of N-(t-butoxycarbonymethyl)pyridinium perchlorate with sodium hydride in acetonitrile, reacts with trifluoroacetonitrile to give 3-(t-butoxycarbonyl)-2-(trifluoromethyl)-imidazopyridine (II), pyridinium 4,5-dihydro-4-oxo-2,6-bis(trifluoromethyl)pyrimidin-5-ylide (III), and N-pyridinium perchlorate (IV).Formation of the last two products, plus the fact that when treated with sodium hydride the perchlorate (IV) yields the imidazopyridine (II), provides powerful evidence in support of a stepwise mechanism for the 1,3-dipolar cycloaddition involved in formation of the imidazopyridine nucleus in (II).
