共查询到6条相似文献,搜索用时 0 毫秒
1.
Sayed M. Riyadh 《中国化学会会志》2005,52(3):545-551
Treatment of 6‐hydroxy‐5‐phenylazo‐2‐thioxo‐4(1H)‐pyrimidinone 1 with a series of hydrazonoyl halides 2 and N,2‐diaryl‐diazinecarbohydrazonoyl halides 9 in dioxane in the presence of triethylamine under reflux furnishes 6‐phenylazo and 3,6‐bis(arylazo)‐7‐hydroxy‐1H‐[1,2,4]triazolo[4,3‐a]pyrimidin‐5(4H)‐one derivatives 7 and 10 , respectively. The biological activities of the products were evaluated. 相似文献
2.
Vladimír Mrkvička Antonín Lyčka Robert Vícha Antonín Klásek 《Helvetica chimica acta》2011,94(1):78-91
3‐Hydroxyquinoline‐2,4‐diones 1 react with isocyanates to give novel 1,2,3,4‐tetrahydro‐2,4‐dioxoquinolin‐3‐yl (alkyl/aryl)carbamates 2 and/or 1,9b‐dihydro‐9b‐hydroxyoxazolo[5,4‐c]quinoline‐2,4(3aH,5H)‐diones 3 . Both of these compounds are converted, by boiling in cyclohexylbenzene solution in the presence of Ph3P or 4‐(dimethylamino)pyridine, to give 3‐(acyloxy)‐1,3‐dihydro‐2H‐indol‐2‐ones 8 . All compounds were characterized by IR, and 1H‐ and 13C‐NMR spectroscopy, as well as by EI mass spectrometry. 相似文献
3.
《Magnetic resonance in chemistry : MRC》2002,40(8):529-532
The 1H{15N} NMR spectrum of 5,7‐diphenyl‐1,2,4‐triazolo[1,5‐a]‐pyrimidine ( 3 ) was measured by GHMQC, unambiguously assigned and compared with the spectra of 1,2,4‐triazolo[1,5‐a]pyrimidine ( 1 ) and 5,7‐dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine ( 2 ). A series of Au(III) chloride complexes of general formula AuLCl3, where L = 1 , 2 , 3 , was synthesized and studied by 1HH{15N} GHMQC and 1H{13C} GHMBC. Low‐frequency shifts of 72–74 ppm (15N) and 5–6 ppm (13C) were observed upon complexation by Au(III) ions for the coordination site N‐3 and adjacent C‐2, C‐3a atoms, respectively. The 13C signals of C‐5, C‐6, C‐7 and the 1H resonances of H‐2, H‐6 were shifted to higher frequency. Comparison with analogous Pd(II), Pt(II) and Pt(IV) complexes revealed that in the case of Au(III) coordination the 15N shifts were relatively smaller, whereas those for 13C and 1H were larger. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
4.
《Magnetic resonance in chemistry : MRC》2002,40(2):114-122
1H and 13C NMR spectroscopy of a series of 1‐vinyl‐2‐(2′‐heteroaryl)‐pyrroles were employed for the analysis of their electronic and spatial structure. The C—H···N intramolecular interaction between the α‐hydrogen of the vinyl group and the pyridine nitrogen, a kind of hydrogen bonding, was detected in 1‐vinyl‐2‐(2′‐pyridyl)pyrrole, which disappeared in its iodide methyl derivative. It was shown that this interaction is stronger than the C—H···O and C—H···S interactions in 1‐vinyl‐2‐(2′‐furyl)‐ and ‐2‐(2′‐thienyl)‐pyrroles. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
5.
Abdolkarim Zare Maria Merajoddin Fereshteh Abi Ahmad Reza Moosavi‐Zare Mohammad Mokhlesi Mohammad Ali Zolfigol Zhila Asgari Vahid Khakyzadeh Alireza Hasaninejad Ali Khalafi‐Nezhad Abolfath Parhami 《中国化学会会志》2012,59(7):860-865
Trityl chloride (triphenylmethyl chloride, TrCl, Ph3CCl) is utilized as an efficient and homogeneous organocatalyst for the synthesis of 14‐aryl‐14H‐dibenzo[a,j]xanthenes from β‐naphthol and arylaldehydes under solvent‐free conditions. Moreover, a plausible mechanism is suggested based on the literature and on in situ formation of trityl carbocation with inherent instability during the reaction. 相似文献
6.
Mehdi Rimaz Nader Noroozi Pesyan Jabbar Khalafy 《Magnetic resonance in chemistry : MRC》2010,48(4):276-285
The tautomerism of the synthesized 3‐arylpyrimido[4,5‐c]pyridazine‐5,7(6H,8H)‐diones ( 1a–d ) and 3‐aryl‐7‐thioxo‐7,8‐dihydro‐6H‐pyrimido[4,5‐c]pyridazine‐5‐ones ( 2a–d ) was studied in dimethyl sulfoxide (DMSO)‐d6. 1H NMR spectra of 1a–d showed a clustered water molecule in the structure backbone that is attached by strong intermolecular H bonding. The relation between the temperature and H bonding of the clustered water molecule with 1a was also studied as representative. The relation between the electronegativity (χ) of the substituent on phenyl ring and the chemical shifts of clustered water protons in 1a–d was also studied. All of 1a–d and also 2d compounds existed in lactam ( I ) form, whereas 2a–c compounds have two distinguished tautomers in DMSO‐d6 [lactam ( I ) and lactim ( II ) forms]. The solvent‐substrate proton exchange was examined in compounds 1a–d and 2a–d by adding one drop of D2O. All compounds (except 1d ) showed proton/deuterium exchange of the clustered water protons in DMSO by adding one drop of D2O. Some compounds (but not all of them) that are easily soluble in DMSO‐d6 containing D2O showed isotopic splitting (β‐isotope effect) in their 13C NMR spectra. Among them, compound 1a was the best evidence to help the spectral assignments and structure determination of predominant tautomer by carbon‐13 splitting (β‐isotope effect). Copyright © 2010 John Wiley & Sons, Ltd. 相似文献