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21.
A.?R.?MustafinaEmail author L.?S.?Kuznetsova A.?S.?Michailov V.?E.?Kataev A.?I.?Konovalov W.?D.?Habicher 《Journal of solution chemistry》2004,33(10):1257-1276
The complexation of a macrocycle containing thiopyrimidine and uracil moieties (M) with amino acids and some dicarboxylic acids was studied by pH-metric, UV-VIS, 1H NMR spectroscopy methods in chloroform, methanol, aqueous 1,4-dioxane, and biphasic water–chloroform media. The complexation of M with acids is too weak to solubilize them from the solid state into chloroform solutions containing M. The 1H NMR spectra and pH-metric data of aqueous 1,4-dioxane (80 vol.%) reveal the pH-dependent 1:1 binding between M and the acids studied. The protonation of M is not a prerequisite for binding of fumaric, succinic, o-phtalic acids and the series of amino acids, whereas binding of maleic acid requires the protonation of both thiopyrimidine moieties of M. Therefore,M·(H+)2 exhibits strong selectivity towards maleic acid in aqueous 1,4-dioxane and in biphasic water–chloroform media. 相似文献
22.
Srinivasa Rao Dasari Subbaiah Tondepu Lakshmana Rao Vadali Nareshvarma Seelam 《合成通讯》2020,50(19):2950-2961
Abstract Polyethylene glycol-400 (PEG-400) has been developed as an efficient and eco-friendly reaction medium for the synthesis of new isoxazolyl pyrido[2,3-d]pyrimidine derivatives 11 from isoxazolyl cyanoacetamide synthon 7. Compound 7 was employed with various aromatic aldehydes 8 and malononitrile 9 in the presence of triethylamine (Et3N) to afford the corresponding (E)-6-amino-1-(3-methyl-5-styrylisoxazol-4-yl)-2-oxo-4-phenyl-1,2-dihydro- pyridine-3,5-dicarbonitrile 10 at room temperature by using PEG-400 as a solvent medium as well as catalyst. The intermediate 10 on treatment with thiourea in the presence of PEG-400 at 90?°C to give the target compounds isoxazolyl pyrido[2,3-d]pyrimidines 11 in good to excellent yields. The newly synthesized compounds 10 and 11 were characterized by IR, 1H NMR, 13C NMR, and HRMS analysis. The target compounds 11a-x was screened for their anti-inflammatory and analgesic activities. Among the tested compounds, the compounds 11s, 11t, 11u, 11v, 11w, and 11x showed significant anti-inflammatory and potent analgesic activities as that of reference drugs. The advantages of this protocol are operational simplicity, catalyst free, environmental safety, wide substrate scope, good yields, and PEG-400 can be recovered and reused. Most significant of all, this protocol is green. 相似文献
23.
An extremely short synthesis of 2,2-dimethyl-3-hydroxymethyl cyclopentanone 2 (R1 = R2 = Me), an advanced intermediate in the synthesis of the pheromone planococcyl acetate 3, is described. 相似文献
24.
《Magnetic resonance in chemistry : MRC》2018,56(8):775-781
Recently, it has been reported that large nJCC correlations can sometimes be observed in 1,1‐ADEQUATE spectra with significant intensity, which opens the possibility of structural misassignment. In this work, we have focused on pyrimidine‐based compounds, which exhibit multiple bond correlations in the 1,1‐ADEQUATE experiment as a consequence of 3JCC coupling constants greater than 10 Hz. Results are supported by both the experimental measurement of 3JCC coupling constants in question using J‐modulated‐ADEQUATE and density functional theory calculations. 相似文献
25.
Carbonyl compounds reacted with stable phosphonium ylides in D2O to give α-deuterated-α,β-unsaturated carbonyl compounds in the same flask. The chemical yield and deuterium incorporation are excellent under our procedure. The fragile group like ozonide was compatible with our reaction condition. 相似文献
26.
Die in hochaufgelösten Protonenresonanzspektren von 15N-markierten Pyrimidinderivaten infolge der indirekten Spin-Spin-Kopplung zwischen 15N und dem um zwei Bindungen entfernten Proton auftretenden Aufspaltungen liefern Aussagen über den Ort der Markierung im Pyrimidinring. Quantitative Angaben über die relative Häufigkeiten von 15N in diesen Positionen werden unter Verwendung der Rechentechnik erhalten. Die Ergebnisse über die relative Häufigkeiten von 15N im gesamten Molekül stimmen gut mit den massenspektrometrischen Werten überein. 相似文献
27.
Essam Kh. Ahmed 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):667-679
New ethyl 3-(substituted)-4-oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydropyrido[4',3':4,5]thieno-[2,3-d]pyrimidine-7-carboxylates ( 3a , b ), ( 6 ),( 11-13 ), ethyl 3-methyl-5-oxo-2,3,6,9-tetrahydro 5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]pyrimidine-8(7H)-carboxylate ( 4 ), and ethyl 2-methyl-5-oxo-2,3,6,9-tetrahydro-5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]-pyrimidine-8(7H)-carboxylate ( 8 ) have been synthesized from diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate 1. The structure of these compounds as well as their intermediates have been established by their spectral data. 相似文献
28.
Cemil İbiş Zeliha Gökmen Nihal Yilmaz Bozkurt 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2907-2914
Mono(thio)substituted dienes 1a-1b gave compounds 3a-c and 5d-g with piperazine and piperidine derivatives in dichloromethane. Compounds 8 , 9 , and 10 were obtained from the reactions of perchlorobutadiene ( 6 ) with 1,4-butanedithiol ( 7 ) in ethanol in the presence of sodium hydroxide. Compounds 12a-b , 13a-b were obtained from the reactions of perchlorobutadiene ( 6 ) with allylmercaptan (CH 2 =CH--CH 2 --SH) and mercaptoethanol (HO--CH 2 --CH 2 --SH). 相似文献
29.
《高分子科学杂志,A辑:纯化学与应用化学》2013,50(1-2):133-143
New silicon-containing disubstituted polyacetylene was prepared by the polymerization of BTMSA having two bulky substituents (n-butyl and trimethylsilyl) using transition metal catalysts. The polymerization proceeded in a mild manner and the final polymer yield was generally lower than those of silicon-containing monosubstituted acetylenes by the similar catalyst system. The characterization on the polymer structure revealed that the resulting poly(BTMSA) have a conjugated backbone system, but the polymers have peculiar copolymer composition of poly-(BTMSA) and poly(1-hexyne) due to the spontaneous desilylation during the polymerization. The fluoride-ion induced desilylation of poly(BTMSA) using n-Bu4N+F? in THF yielded a completely desilylated product, pure poly(1-hexyne). 相似文献
30.