Conversion of 3-Formylchromones into Pyrrole and Thiophene Derivatives

Fitton, A. O.; Frost, Jonathan R.; Suschitzky, H.; Houghton, Peter G.

doi:10.1055/s-1977-24298

Cited by 25 publications

(10 citation statements)

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“…was successful and the spiroheterocyclic adduct spiro[(1´-methyl-2´-imido-4´-oxo)-1´, 3´-diazolane-5´, 2-(7-methyl-9-oxo-2, 3, 4, 4a tetrahydroxantene)]-3, 4-dicarboxylic acid (11) was formed in 64% yield. The proposed structure was confirmed by 13 C NMR. Similar Diels -Alder reactions were reported previously [18].…”

Section: Resultsmentioning

confidence: 59%

“…The 5-(2-hydroxyphenyl)-4-(hydroxy-methylidene)-2-(1-methylguanidino)-2-pentenoic acid hydrolysis products (10) were obtained only by refluxing compounds 5 in concentrated hydrochloric acid. We propose the structure of compounds 10, which contain guanidinyl, carboxyl and enolic groups on the basis of 1 H NMR, 13 C NMR spectra and elemental analysis. Compounds 10 could be regarded as a mixtures of isomers with a very fast tautomeric equilibrium of both enolic and oxo groups.…”

Section: Resultsmentioning

confidence: 99%

“…Thus prepared were compounds 10a, 10e and 10f 13 C NMR spectral data for compound 10e [δ(ppm); DMSO -d 6 , 300 MHz] …”

Section: Acid Hydrolysis Of Compounds 5a 5e and 5fmentioning

confidence: 99%

“…Five-membered ring heterocycles 2-4 are known as precursors of α-amino acids and they can be condensed easily with aldehydes. It is known that condensations of creatinine with aldehydes [11,12] as well as the Gränacher synthesis [13] with rhodanine under classical conditions take several hours at high temperatures (160-180°C).…”

Section: Introductionmentioning

confidence: 99%

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Effect of Microwave Irradiation on the Condensation of 6-Substituted 3-Formylchromones with Some Five-membered Heterocyclic Compounds

et al. 2000

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Different types of 3-substituted 4H-4-oxobenzopyrans were prepared by microwave irradiation as well as by a classical method. The beneficial effect of microwave irradiation on the aldol condensation of 3-formylchromones with 2-imino-1-methylimidazolidine-4-one (creatinine), 2-thioxoimidazolidine-4-one (thiohydantoin) and 2-ethyl-2-thioxothiazolidin-4-one (3-ethylrhodanine) in different reaction media is described. Our results show that the effect of microwave irradiation on the reactions studied was a shortening of the reaction times and a smooth increase in the yields. The subsequent reactions of the product with some nucleophiles are discussed. The structure of the products was proven by elemental analysis, IR and NMR spectra.

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Section: Resultsmentioning

confidence: 59%

Section: Resultsmentioning

confidence: 99%

“…Thus prepared were compounds 10a, 10e and 10f 13 C NMR spectral data for compound 10e [δ(ppm); DMSO -d 6 , 300 MHz] …”

Section: Acid Hydrolysis Of Compounds 5a 5e and 5fmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of Microwave Irradiation on the Condensation of 6-Substituted 3-Formylchromones with Some Five-membered Heterocyclic Compounds

et al. 2000

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“…Oxazolones 87 were readily obtained from the reaction of 3-formylchromones 1a,b and N-acetyl/ benzoylglycine in acetic anhydride containing freshly fused sodium acetate (Scheme 42) [17,70,71].…”

Section: Scheme 41mentioning

confidence: 99%