Benzylcyanide and 4-nitrobenzylcyanide condensed with triethyl orthoformate and piperidine or morpholine to yield 2-aryl-2-piperidinyl or 2-morpholinylacrylonitriles. These coupled with aromatic diazonium salts to yield the 2-arylhydrazno-2-arylethane nitriles in good yields. The latter were converted into 4-aminopyrazoles in good yields using the Thorpe-Ziegler cyclization.
A Route to Dicyanomethylene Pyridines and Substituted Benzonitriles Utilizing Malononitrile Dimer as a Precursor
作者:Noha M. Helmy、Fatma E. M. El-Baih、Monirah A. Al-Alshaikh、Moustafa S. Moustafa
DOI:10.3390/molecules16010298
日期:——
The conditions of the reaction of malononitrile dimer with enaminones and arylidenemalononitrile could be adapted to yield either pyridines or benzene derivatives. A new synthesis of pyrido[1,2-a]pyrimidines from the reaction of malononitrile dimer 1 and 2-phenyl-3-piperidin-1-yl-acrylonitrile (11) is described. Compound 1 condensed with DMFDMA to yield an enaminonitrile that reacted with hydrazine hydrate to yield N',4,6-triamino-2H-pyrazolo[3,4-b]pyridine-5-carboxamidine (17).
Enamines in Heterocyclic Synthesis: A Novel Simple and Efficient Route to Condensed Pyridazines
作者:Elham S. Darwish、Mahmoud A. Abdelrahman、Abdellatif M. Salaheldin
DOI:10.1515/znb-2011-0607
日期:2011.6.1
An efficient and easy preparation of enamine derivatives, via active methyl and methylene compounds by in situ-generated 1-(diethoxymethyl)piperidine, produced from the mixture of triethyl orthoformate/piperidine/DMF, are described. Some new pyridazinone derivatives have been synthesized from the reaction of enamines with hydrazine hydrate and cyanoacid hydrazide. Graphical Abstract Enamines in Heterocyclic
Novel rearrangement reactions leading to the formation of 2-piperidinyl-tetrahydroquinolinones were observed to occur in reactions of enaminonitrile with the 1,3-cyclohexanedione derivatives. In contrast, 2-phenyl-3-(piperidin-1-yl)acrylonitrile was observed to react with 5,5-dimethyl-1,3-cyclohexanedione to yield 7,7-dimethyl-3-phenyl-7,8-dihydroquinoline-2,5(1H,6H)-dione. While not participating in reaction with 5,5-dimethyl-1,3-cyclohexanedione, 2-benzoyl-3-(dimethylamino)acrylonitrile reacted with 3-oxo-3-phenylpropanenitrile to yield 2-benzoyl-4-[hydroxy(phenyl)-methylene]pent-2-enedinitrile and 5-benzoyl-6-hydroxy-2-phenylnicotinonitrile. The structure of 2-benzoyl-4-[hydroxy(phenyl)methylene]pent-2-enedinitrile along with other substances prepared in this effort were determined by X-ray crystallographic analysis.
Enaminonitriles in Heterocyclic Synthesis: Novel Synthesis of 3-Aminopyrroles and Pyrrolo[3,2-d]pyrimidine Derivatives
作者:Abdellatif M. Salaheldin
DOI:10.1515/znb-2008-0514
日期:2008.5.1
Several new 3-aminopyrrole derivatives have been synthesized from 3-substituted amino-2-phenylacrylonitriles using Thorpe-Ziegler cyclization. These substituted pyrroles are readily converted into 5H-pyrrolo[3,2-d]pyrimidines (9-deazapurines).