6009-46-7Relevant academic research and scientific papers
New and general nitrogen heterocycle synthesis: Use of heteropoly acids as a heterogeneous recyclable catalyst
Hekmatshoar, Rahim,Sadjadi, Sodeh,Sadjadi, Samaheh,Heravi, Majid M.,Beheshtiha, Yahya S.,Bamoharram, Fatemeh F.
experimental part, p. 1708 - 1716 (2010/07/15)
An efficient synthetic method of six-and five-member nitrogen heterocyclic compounds was developed. Nitrogen heterocyclic compounds were prepared by condensation of the-dicarbonyl compounds with the corresponding-or-amino alcohols, subsequent cyclization, and spontaneous aromatization in the presence of a catalytic amount of Keggin-type heteropoly acids under very mild conditions. Copyright
Synthesis of 3-Acylpyrroles, 3-(Alkoxycarbonyl)pyrroles, 1,5,6,7-Tetrahydro-4H-indol-4-ones and 3-Benzoylpyridines Based on Staudinger-Aza-Wittig Reactions of 1,3-Dicarbonyl Compounds with 2- and 3-Azido-1,1-dialkoxy- alkanes
Bellur, Esen,Yawer, Mirza A.,Hussain, Ibrar,Riahi, Abdolmajid,Fatunsin, Olumide,Fischer, Christine,Langer, Peter
experimental part, p. 227 - 242 (2009/06/24)
The Staudinger-aza-Wittig reaction of 1,3-dicarbonyl compounds with 2-azido-1,1-diethoxyethane and subsequent cy- clization allowed an efficient synthesis of a variety of pyrroles, 1,5,6,7-tetrahydro-4H-indol-4-ones, and of a pyridine. Georg Thieme Verlag
Synthesis of functionalized pyrroles and 6,7-dihydro-1H-indol-4(5H)-ones by reaction of 1,3-dicarbonyl compounds with 2-azido-1,1-diethoxyethane
Bellur, Esen,Langer, Peter
, p. 2151 - 2154 (2007/10/03)
The condensation of 1,3-dicarbonyl compounds with 2-azido-1,1- diethoxyethane and subsequent cyclization allowed an efficient synthesis of a variety of pyrroles and 6,7-dihydro-1H-indol-4(5H)-ones.
Synthesis of 2-alkylidenepyrrolidines, pyrroles, and indoles by condensation of silyl enol ethers and 1,3-bis-silyl enol ethers with 1-azido-2,2-dimethoxyethane and subsequent reductive cyclization
Bellur, Esen,Goerls, Helmar,Langer, Peter
, p. 4751 - 4761 (2007/10/03)
The condensation of 1,3-bis-silyl enol ethers with 1-azido-2,2- dimethoxyethane and subsequent reductive cyclization allowed an efficient regio- and diastereoselective synthesis of a variety of 2-alkylidene-4- methoxypyrrolidines. The thermal elimination of methanol resulted in the formation of functionalized pyrroles. Similarly, 2,3,3a,4,5,6-hexahydro-2,3- benzopyrroles were prepared and transformed into 4,5,6,7-tetrahydro-2,3- benzopyrroles. In contrast, treatment of 2-alkylidenepyrrolidines with trifluoroacetic acid resulted in formation of indoles by [4 + 2] cycloaddition and subsequent extrusion of a nitrogen atom.
Versatility of Weinreb amides in the Knorr pyrrole synthesis
Alberola, Angel,Ortega, Alfonso Gonzalez,Sadaba, M. Luisa,Sanudo, Carmen
, p. 6555 - 6566 (2007/10/03)
N-Methoxy-N-methyl-α-enaminocarboxamides were prepared starting from enamines and Weinreb α-aminoamides. Their reaction with oganometallic compounds and subsequent cyclization constitute a versatile alternative in the Knorr pyrrole synthesis.
The chemistry of pyrrolic compounds. LXXI synthesis of the ring c and the ring D demethyl analogues of deoxophylloerythroetioporphyrin (dpep)
Clezy, Peter S.,Salek, Abdoreza
, p. 265 - 272 (2007/10/03)
The demethyl analogues (1d,e) of dpep have been prepared by utilizing in each case an oxidative cyclization of an intermediate biladiene-ac to assemble the porphyrin macrocycle.
Magnetic Circular Dichroism Studies. 66. Synthesis of Demethyl Monosubstituted Porphyrins. The Effect of Substituent Conformation on the Magnetic Circular Dichroism Spectra of Ethoxycarbonyl Porphyrins.
Wee, Andrew G. H.,Shu, Arthur Y. L.,Bunnenberg, Edward,Djerassi, Carl
, p. 3327 - 3336 (2007/10/02)
The synthesis of a series of demethyl monosubstituted (acetyl, vinyl, formyl, cyano, and ethoxycarbonyl) free-base porphyrins (6b-f) is described.The key intermediates, 5-formyl-5'-methyldipyrrylmethanes 16a and 26, used in this synthesis are prepared in high yields by an improved procedure which entails decarboxylation of the 5-carboxy-5'-methyldipyrrylmethanes 15a and 25 in trifluoroacetic acid and subsequent formylation of the decarboxylated dipyrrylmethane with a mixture of dimethylformamide and p-nitrobenzoyl chloride.The preparation of the demethylformylporphyrin 6d from the demethylvinylporphyrin 6c was succesfully accomplished by the use of thallium(III) as a "protecting group" for the macrocycle.This series of monosustituted porphyrins allows, or the first time, the assessment of the electronic and optical consequences of the substituent effects on the porphyrin macrocycle on the same sterically unconstrained basis as now exists for a wide variety of other cyclic ?-electron systems.This is illustrated by comparing the MCD spectra of the methyl and demethyl ethoxycarbonyl free-base porphyrins.The observed sign variations of the MCD bands for these two porphyrins are explained with the perimeter model approach previously elaborated for substituted porphyrins.
Intramolecular Michael-type additions. II. Synthesis of derivatives of 7-thia-2-azabicyclooct-3-ene, a novel heterocyclic ring system
Baggs, Marion E. M.,Gregory, Brian
, p. 794 - 802 (2007/10/02)
The isothiouronium salt derived from dimethyl 4-chloromethyl-1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate reacted with ammonium hydroxide to give dimethyl 7-thia-2-aza-1,3-dimethylbicyclooct-3-ene-4,8-dicarboxylate, which could be converted back to a dihydropyridine using iodomethane.Replacement of ammonium hydroxyde by sodium hydroxyde afforded a tetrahydro- and a dihydrothienopyridine as by-products. 3,5-diacetyl-4-chloromethyl-1,4-dihydro-2,6-dimethylpyridine reacted with thiourea, followed by ammonium hydroxide, to give 3-acetyl-2-methylpyrrole, 4-acetyl- and 4,8-diacetyl-7-thia-2-aza-1,3-dimethylbicyclooct-3-ene.The structure and stereochemistry of the novel 7-thia-2-azabicyclooctenes are established using spectroscopic methods.The mechanism of their formation is discussed in terms of Baldwin's rules.
