72564-20-6Relevant academic research and scientific papers
Structure and tautomerism of azo coupling products from N-alkylenaminones derived from acetylacetone and benzoylacetone in solid phase and in solution
Simunek, Petr,Svobodova, Marketa,Bertolasi, Valerio,Pretto, Loretta,Lycka, Antonin,Machacek, Vladimir
, p. 429 - 438 (2007)
A series of azo coupling products have been prepared by reaction of substituted benzenediazonium tetrafluoroborates with N-alkyl 4-aminopent-3-en-2-ones or 3-amino-1-phenylbut-2-en-1-ones. The structure and tautomerism of the reaction products were studied by means of single-crystal X-ray study and by NMR spectroscopy in deuteriochloroform solution. The azo coupling products obtained from 4-methylaminopent-3-en-2-ones (3a-i) exist in CDCl3 solution as E/Z isomer mixtures with the Z isomer strongly predominating. The major isomer is a mixture of enamino-azo and imino-hydrazo tautomers with the former predominating. The proportion of the azo form depends on substitution of the benzene ring of the diazonium salt and decreases in the order of MeO > Me > Br > NO2. The position of tautomeric equilibrium is practically unaffected by switching from 4-methylaminopent-3-en- 2-ones to 3-methylamino-1-phenylbut-2-en-1-ones. In the solid phase, the azo form always predominates; substitution of diazonium salt and at N3 nitrogen does not significantly affect the position of the tautomeric equilibrium. The azo coupling products always exist in the form of a single Z isomer. All determined structures, in the solid state, consist of a mixture of the two tautomeric forms, amino-diazenyl and imino-hydrazone, in ratios ranging from 82/18 to 91/9%. The weighed superimposition of both the hydrogen-bonded N1=N2-C1=C2-N3H/ HN1-N2=C1-C2=N3 heterodienic fragments, however, do not allow to clarify the effects of the para-substituents at the N1-phenyl ring both on the N1...N3 hydrogen-bond distances and on the bond lengths in the heterodienic systems within the series 3a-c,f and 4a-c,e,f. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
Solvent-free synthesis of pyrrole derivatives
Rostami-Charati, Faramarz,Hossaini, Zinatossadat,Khalilzadeh, Mohammad A.,Jafaryan, Hojatollah
experimental part, p. 217 - 220 (2012/04/23)
A one-pot synthesis of pyrrole derivatives via reaction between activated carbonyl compounds, primary amines, and 1,3-dicarbonyls under solvent-free conditions is described..
ADDITION OF ORGANOCUPRATES TO KETOKETENIMINES. SYNTHESIS OF β-ENAMINOKETONES
Cal, Teresa de la,Cristobal, Blanca I.,Cuadrado, Purification,Gonzalez, Ana M,Pulido, Fco. J.
, p. 1039 - 1046 (2007/10/02)
Base-induced ring cleavage of 3-unsabstituted isoxazolium salts followed by reaction of the resulting ketoketenimine with organocuprates affords asymmetric β-enaminoketones in high yields.
