54818-68-7Relevant academic research and scientific papers
Chitosan based heterogeneous catalyses: Chitosan-grafted-poly(4- Vinylpyridne) as an efficient catalyst for michael additions and alkylpyridazinyl carbonitrile oxidation
Khalil, Khaled D.,Al-Matar, Hamad M.
, p. 5288 - 5305 (2013/07/19)
Chitosan-grafted-poly(4-vinylpyridine) (Cs-PVP) copolymers could be synthesized under heterogeneous conditions in presence of a potassium persulfate and sodium sulfite redox system. The synthesized graft copolymer could be utilized effectively, in the form of beads, as an efficient catalyst for Michael additions of active methylenes to functionally substituted alkenes. Moreover, methyl moiety oxidation in methyl pyridazinyl carbonitriles by H 2O2 in the presence of chitosan-g-polyvinyl pyridine-supported iron (III) complex, Cs-PVP/Fe, could be affected. A variety of pyrans, naphthopyrans, and thiopyrans could be synthesized efficiently in the presence of these graft copolymer beads by novel catalytic routes. These polymeric catalysts could be used instead of the old toxic commercial organic basic catalysts, piperidine or pyridine, and could be readily isolated from the reaction mixture and recycled several times without significant loss of catalytic activity.
About the reaction of β-dimethylamino-α,β-enones with active methylene nitriles
Abdelrazek, Fathy M.,Elsayed, Akram N.
experimental part, p. 949 - 953 (2009/12/05)
(Chemical Equation Presented) The reaction of 3-dimethylamino-1- arylpropenone derivatives with active methylene nitriles was reinvestigated and a plausible mechanism to account for the results is suggested. X-ray crystallographic study supported the sugg
Enaminones as building blocks in heterocyclic syntheses: Reinvestigating the product structures of enaminones with malononitrile. A novel route to 6-substituted-3-oxo-2,3-dihydropyridazine-4-carboxylic acids
Alnajjar, Abdul-Aziz,Abdelkhalik, Mervat Mohammed,Al-Enezi, Amal,Elnagdi, Mohamed Hilmy
experimental part, p. 68 - 77 (2009/08/15)
The reported structures of reaction products of enaminones with malononitrile in ethanolic piperidine are revised. A novel route to 2,3-dihydropyridazine-4-carboxylic acids 4a-c via reactions of 2-cyano-5-(dimethylamino)-5-arylpenta-2,4-dienamides 8a-c wi
Orthoamides. L. Contribution to the chemistry of propiolaldehydaminales - Synthesis and transformations to push-pull-substituted buta-1,3-dienes, cyclobutanes, vinylogous amidinium salts and 1,2,3-triazoles
Kiesel, Michael,Haug, Erwin,Kantlehner, Willi
, p. 159 - 170 (2007/10/03)
Tert-butylaminalester 5 reacts with terminal alkynes to give aminals of substituted propiolaldehydes 3c,d. The aminal 3a is accessible from N,N,N′,N′-tetramethylformamidinium chloride (7b) and sodium acetylide. The aminals 3b,c can also be prepared from bis(dimethylamino)acetonitrile 8 and terminal alkynes in the presence of sodium hydride. The nitrile 8 is also useful for the preparation of the bis-aminal of acetylenedialdehyde 6. The aminal 3e can be transaminated by heating with secondary amines to give the aminals 3f-i. The aminals 3a-i react with strong CH2-acidic compounds (pKa between 9 and 14) to give the 1-dialkylamino-1,3-butadienes 10. The isomeric 1-dialkylamino-butadienes 18 can be obtained from the condensation of the CH-acidic cinnamic acid derivatives 19 with dimethylformamidedimethylacetal. CH and NH-acidic compounds as cyanacetamide react with the aminals 3c,e exclusively with the acidic methylene group to produce the enamines 10h,t. The acylformamidine 21 can be obtained from 10t and tert-butylaminalester 5. The pyridone 22 is accessible from the condensation product 10h by thermal cyclization. The pyrido[2,3-d]pyrimidine 26 is formed in the reaction of the 6-amino-uracile 23 with the aminal 3a. In an unexpected reaction the 1,2-bis(cyano-dialkylaminomethylene)-cyclobutanes 28a-d result from the action of trimethylsilylcyanide on the aminals 3e-h. The corresponding reaction with trimethylsilylisothiocyanate affords the vinylogous amidinium thiocyanates 34a,b. In the reaction of trimethylsilylazide and the aminals 3 are produced the 4-(dialkylaminomethylene)-4H-1,2,3-triazoles 38. Johann Ambrosius Barth 1997.
