20730-02-3Relevant academic research and scientific papers
A formal [3+2] cycloaddition reaction of: N -methylimidazole as a masked hydrogen cyanide: Access to 1,3-disubstitued-1 H -1,2,4-triazoles
Yavari, Issa,Khaledian, Omid
supporting information, p. 9150 - 9153 (2020/10/02)
N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C-N bond cleavages. This journal is
[3+2]-cycloaddition of in situ generated nitrile imines and acetylene for assembling of 1,3-disubstituted pyrazoles with quantitative deuterium labeling
Voronin, Vladimir V.,Ledovskaya, Maria S.,Gordeev, Evgeniy G.,Rodygin, Konstantin S.,Ananikov, Valentine P.
, p. 3819 - 3828 (2018/04/14)
A novel synthetic methodology for the preparation of 1,3-disubstituted pyrazoles from in situ generated nitrile imines and acetylene is reported. The reactions are performed in a simple two-chamber reactor. One part of the reactor is loaded with hydrazonoyl chloride precursors of active nitrile imine species and a base. The other part is used to generate acetylene from CaC2 and water. Partitioning of the reactants improves the yields of desired pyrazoles up to 99% and simplifies their isolation to a simple procedure of solvent evaporation. The approach requires no complex equipment and utilizes inexpensive, safe, and easy to handle calcium carbide as a starting material. A model deuterium incorporation is carried out according to the developed methodology, producing a series of novel 4,5-dideuteropyrazoles with excellent deuterium enrichment. Theoretical calculations on reaction mechanism and characterization of possible intermediate structures were performed.
Synthesis of indoles via alkylidenation of acyl hydrazides
Hisler, Kevin,Commeureuc, Aurélien G.J.,Zhou, Sheng-ze,Murphy, John A.
supporting information; experimental part, p. 3290 - 3293 (2009/08/17)
Indoles have been synthesised via alkylidenation of acyl phenylhydrazides using phosphoranes and the Petasis reagent, followed by in situ thermal rearrangement of the product enehydrazines. The Petasis reagent provides an essentially neutral equivalent of the [acid-catalysed] Fischer indole synthesis, but with acyl phenylhydrazides as starting substrates. Alkylidene triphenylphosphoranes convert aroyl phenylhydrazides to indoles, but acyl phenylhydrazides derived from aliphatic carboxylic acids undergo a Brunner reaction to form indolin-2-ones.
A facile synthesis of acylhydrazines from acylbenzotriazoles
Wang, Xiaoxia,Yu, Hongping,Xu, Peifang,Zheng, Renwei
, p. 595 - 597 (2007/10/03)
Acylbenzotriazoles were found to react with substituted hydrazines and aqueous hydrazine under very mild conditions, thus affording a facile synthesis of three types of acylhydrazines in moderate to excellent yields.
Preparation, properties, and reductive alkylation of arylhydrazides
Verardo, Giancarlo,Toniutti, Nicoletta,Giumanini, Angelo G.
, p. 1180 - 1187 (2007/10/03)
1 [-Acy]-2-arylhydrazines (1), readily obtained in high yield from the condensation of arylhydrazines and the appropriate liquid carboxylic acid (2), underwent reductive alkylation with the same or different liquid carboxylic acids (2) and NaBH4 to give 1-acyl-2-alkyl-2-arylhydrazines (3) in good to moderate yields. The carboxylic acid has both the role of supplying the entering alkyl group and of acting as solvent. Most likely, it also modifies the BH4- anion to an active reducing agent under those conditions. The 1H NMR criteria for identifying the location of acylation of hydrazines and E and Z isomers are given. The MS spectra of the prepared hydrazides were analyzed in order to identify relevant structural features leading to specific fragmentations.
Some Observations on the Brunner Reaction
Wolff, Jens,Taddei, Maurizio
, p. 4267 - 4272 (2007/10/02)
Elucidation of the stereochemical course of the Brunner reaction is described.A slight modification in the procedure gives better yields and seems very promising for a more general application of this reaction.
