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Helio G. Bonacorso Rosália Andrighetto Nícolas Krüger Jussara Navarini Alex F. C. Flores Marcos A. P. Martins Nilo Zanatta 《Journal of heterocyclic chemistry》2013,50(Z1):E193-E199
This article reports a convenient and general method for the regioselective synthesis of a new series of 2‐alkyl(aryl)‐8‐methyl‐4‐trifluoromethyl‐7‐aminoquinolines in 86–93% yields, from cycloaromatization reactions of N‐(oxotrifluoroalkenyl)‐2,6‐diaminotoluenes in a strongly acidic medium polyphosphoric acid and absence of solvent. The enaminoketone intermediates were easily isolated from the reaction of 4‐alkoxy‐4‐alkyl(aryl)‐1,1,1‐trifluoroalk‐3‐en‐2‐ones [CF3C(O)CH═C(R)OR1, where R = H, Me, Ph, 4‐FPh, 4‐BrPh, 4‐MePh, and R1 = Me, Et] with 2,6‐diaminotoluene (2,6‐DAT) in methanol under mild conditions, in 46–70% yields. Another synthetic route also allowed the regioselective synthesis of 2‐aryl(heteroaryl)‐4‐methyl‐4‐trifluoromethyl‐7‐aminoquinolines from direct cyclocondensation reactions of 4‐alkoxy‐4‐aryl(heteroaryl)‐1,1,1‐trifluoroalk‐3‐en‐2‐ones with 2,6‐diaminotoluene in methanol under mild conditions, in 21–36% yields. 相似文献
96.
Nilo Zanatta Fabio M. da Silva Andreia M. P. W. da Silva Estefania da C. Aquino Helio G. Bonacorso Marcos A. P. Martins 《Journal of heterocyclic chemistry》2013,50(4):868-873
A simple procedure for the synthesis and characterization of new 3‐alkoxy‐3‐(1H‐tetrazol‐5‐yl)propionic acids and 2‐(1H‐tetrazol‐5‐yl)tetrahydrofuran‐ and ‐(1H‐tetrazol‐5‐yl)‐2H‐pyran‐3‐carboxylic acids from the [2 + 3] cycloaddition reactions between the nitrile group of β‐cyanocarboxylic acids with sodium azide in the presence of zinc chloride is described. The tetrazolic acids were isolated in moderate to good yields and are structurally analogous to succinic acid. 相似文献
97.
Marcos A. P. Martins Paulo Muraro Paulo Beck Pablo Machado Clarissa P. Frizzo Nilo Zanatta 《合成通讯》2013,43(20):3465-3476
Twelve novel 3-alkyl[aryl]-1-carboxamides-5-trichloromethyl-5-hydroxy-4,5-dihydro-lH-pyrazole have been synthesized in good yields (72–90%) using environmentally benign microwave-induced techniques. The compounds were synthesized from the cyclocondensation of 4-alkoxy-1,1,1-trichloro-3-alkyl[aryl]-2-ones [Cl3CC(O)C(R2) = C(R1)OR, where R = Me, Et; R1 = H, Me, Et, Pr, i-Pr, i-Bu, t-Bu, Ph, Ph-4-NO2, Ph-4-F, Ph-4-Cl, Ph-4-Br; and R2 = H, Me] with semicarbazide hydrochloride in the presence of pyridine and using methanol/water (3:1 v/v) as the solvent. The advantages of using microwave irradiation, rather than a conventional method, were demonstrated. 相似文献
98.
Evaluation by empirically derived equations for the substituent effect (EXn and EYn, n = 1 to 6) on the 13C NMR chemical shifts for C-1, C-2, C-3, C-4, C-5 and C-6 in 1-alkylamino-6-ethoxy-1,5-hexadien-3,4-diones 1a-f and 1,6-bis(alkylamino)-1,5-hexadien-3,4-diones 2a-f [XCH=CHC(O)-C(O)CH=CHY, where X, Y = OEt, NH2, PhCH2NH, n-BuNH, i-PrNH, cyclo-C6H11NH, t-BuNH], taking as reference the 1,6-diethoxy-1,5-hexadien-3,4-dione (3), is reported. From the calculated values for the EXn and EYn effects for each substituent it was possible to estimate the chemical shift of each carbon of the compounds 1,2 with excellent precision: 100% of the calculated chemical shifts are found to be within ±0.5ppm. The carbon-13 chemical shifts of C-1, C-2 and C-3 of compounds 1a,2a,3 led a good correlation with carbon charge densities (qr). 相似文献
99.
Marcos A. P. Martins Alex F. C. Flores Giovani P. Bastos Nilo Zanatta Helio G. Bonacorso 《Journal of heterocyclic chemistry》1999,36(4):837-840
The reaction of a series of β-methoxyvinyl trifluoromethyl ketones [CF3COC(R2)?C(OMe)R1, where R1 = Me, -(CH2)3-C3, -CH2)4-C3, Ph and R2 = H, Me, -(CH2)3-C4, -(CH2)4-C4] with N-methylhydroxylamine is reported. The regiochemistry of the reaction are explained by MO calculation data. 相似文献
100.
Ademir F. Morel Adriana Flach Nilo Zanatta Eduardo M. Ethur Marco A. Mostardeiro Ilaine T.S. Gehrke 《Tetrahedron letters》1999,40(52):79-9209
Waltherine-C (5), a novel 14-membered cyclopeptide alkaloid has been isolated, together with four known cyclopeptide alkaloids, waltherine-A (1) and -B (2), scutianine-B (3) and adouetine-Y' (4), from the bark of Waltheria douradinha (Sterculiaceae) from Rio Grande do Sul, Brazil. The structure and NMR assignments of this new alkaloid were determined by 1D and 2D NMR techniques. The stereochemistry of the ring amino acid residue and the N,N-dimethyl amino acid side-chain has been assigned by gas chromatography employing modified cyclodextrins as chiral stationary phases. 相似文献