13017-50-0Relevant academic research and scientific papers
Determination of heats of tautomerization of nitrile-ketenimine by mass spectrometry
Saraví Cisneros, Hebe,Erben, Mauricio F.,Della Védova, Carlos O.,Laurella, Sergio,Allegretti, Patricia E.,Furlong, Jorge J.P.
, p. 125 - 143 (2011)
Tautomerism of some nitriles has been studied by mass spectrometry. The analysis of the corresponding mass spectra has allowed some fragmentations to specific tautomers to be assigned and the heats of tautomerization to be determined through temperature effects and electron energy studies. Experimental determinations are supported by theoretical calculations. The joint analysis of mass spectrometry and DFT-B3LYP data indicate that this tautomeric equilibrium can be studied by the experimental spectrometric strategy employed.
A simple, efficient and green procedure for Knoevenagel condensation in water or under solvent-free conditions
Yu, Ya-Qin,Wang, Zhong-Liang
, p. 288 - 292 (2013)
1,4-Diazabicyclo[2.2.2]octane was used as an efficient catalyst in the Knoevenagel condensation reaction of various kinds of aromatic/aliphatic/ heterocyclic/α,β-unsaturated aldehydes and ketones with active methylene compounds. This is a convenient and rapid method for Knoevenagel condensation, which affords the corresponding substituted electrophilic alkenes in excellent yields. The reaction condition is mild and the method is operationally simple. The products, only E-isomers were detected, did not need to be purified. The use of water as the reaction mediummakes the process environmentally benign. The catalysts can be recycled six times without activity loss.
A convenient and selective one-pot method for the synthesis of monosubstituted secondary alkyl malononitriles
Sammelson, Robert E.,Allen, Mark J.
, p. 543 - 546 (2005)
We have found that α,α-dicyanoalkenes can be efficiently and selectively reduced to α,α-dicyanoalkanes (malononitriles) with NaBH4 in 95% EtOH at 0 °C. In addition, we have determined that the condensation of malononitrile with ketones using absorption alumina as a catalyst can be followed directly, in one pot, by reduction with NaBH 4 in 95% EtOH at 0 °C to provide the monosubstituted secondary alkyl malononitriles in good to excellent yields (42-94%). This procedure provides a convenient alternative to direct alkylation of malononitrile or reduction of α,α-dicyanoalkene intermediates.
Improved synthesis of mono- and disubstituted 2-halonicotinonitriles from alkylidene malononitriles
Longstreet, Ashley R.,Campbell, Brian S.,Gupton, B. Frank,McQuade, D. Tyler
supporting information, p. 5298 - 5301 (2013/11/06)
Pyridines with 2,3,4 and/or 5 substitution remain challenging to prepare. Existing strategies to form multisubstituted 2-halonicotinonitriles via enamines suffer from dimerization of the starting alkylidene malononitriles resulting in low yields. Through alteration of reaction conditions, a new high yielding method into enamines was realized by condensing DMF-DMA and alkylidene malononitriles in the presence of substoichiometric acetic anhydride. Cyclization of the resulting enamines under Pinner conditions provided 2-halonicotinonitriles in high overall yields.
A simple, efficient and green procedure for Knoevenagel condensation catalyzed by [C4dabco][BF4] ionic liquid in water
Xu, Da-Zhen,Liu, Yingjun,Shi, Sen,Wang, Yongmei
experimental part, p. 514 - 517 (2010/08/04)
A convenient and rapid method for Knoevenagel condensation has been developed by using DABCO-base ionic liquid catalysts. This method is applicable to a wide range of aromatic/aliphatic/heterocyclic/α,β-unsaturated aldehydes and ketones with active methyl
Synthesis of substituted amino-cycloalkyl[b]thieno-[3,2-e]pyridines
Seek, Pierre,Thomae, David,Kirsch, Gilbert
, p. 853 - 857 (2008/09/21)
(Chemical Equation Presented) An efficient two respectively three steps procedure for the synthesis of cycloalkyl[b]thieno[3,2-e]-pyridine amines was developed and in general good to very good yields were obtained.
Geminal dinitriles and their reactions: I. Hydrolysis of alkylidene- and cycloalkylidenemalononitriles in aqueous medium
Smirnov,Sevast'yanova
, p. 1703 - 1708 (2007/10/03)
The kinetics of pseudounimolecular hydrolysis of alkylidene- and cycloalkylidenemalononitriles in an aqueous buffer at pH 7 were studied. Correlations between the rate constants and substituent effects were found to fit the Taft-Hancock equation. Electrochemical reduction of alkylidenemalononitriles was studied using 0.2 M tetraethylammonium iodide as supporting electrolyte. The half-wave reduction potentials are related to the substituent constants σ* by the Taft-Zuman equation. Anomalous behavior of 1,1-dicyano-2,3,3-trimethyl-1-butene was observed during the hydrolysis and electrochemical reduction at a dropping mercury electrode.
A Synthesis of Pyrroloquinazolinones, Indoloquinazolinones, Pyrrolothienopyrimidinones, Benzothienopyrrolopyrimidinones and 6H-Cycloheptathienopyrrolopyrimidinones
Suesse, M.,Johne, S.
, p. 647 - 653 (2007/10/02)
α-Cyano-γ-halo-crotonnitriles (1) synthesized (e.g. via Knoevenagel reaction and by subsequent halogenation) react with primary arylamines (2) to substituted 1-aryl-2-amino-3-cyano-pyrroles (3).We found that the reaction yields pyrroloquinazolin-5-
