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991.
A wide range of mono-and disubstituted 2,3-dihydroquinazolin-4(1H)-ones were obtained in high yields by condensation of isatoic anhydride,aldehydes with ammonium salts or primary amines in the presence of strontium chloride in aqueous ethanol under reflux. 相似文献
992.
Gholamabbas Chehardoli Mohammad Ali Zolfigol Seyedeh Bahareh Azimi Ebadollah Alizadeh 《中国化学快报》2011,22(7):827-830
Melamine and poly vinylpyrrolidone(PVP) reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-(H2SO4)3 and PVP-(H2SO4)n.These solid acids were used for the first nitration of bisphenol A as well as other phenols in the presence of NH4NO3.Mono- and di-nitro bisphenol A have been characterized with IR and 1H NMR techniques. 相似文献
993.
Silica gel-supported polyphosphoric acid(PPA-SiO2) was found to be an efficient catalyst for the one-pot four-component Hantzsch condensation reaction of aryl aldehydes,dimedone,ethyl acetoacetate and ammonium acetate to afford the corresponding polyhydroquinoline derivatives in high yields.The main advantages of the present approach are short reaction times,clean reaction profiles,simple experimental and workup procedures. 相似文献
994.
Two new diterpenoids,3,4,18β-cyclopropa-ent-abieta-8(14),13(15)-dien-16,12-olide(1) and 3-oxojolkinolide B(2),were isolated from the roots of Suregada glomerulata(Blume) Baill.Their structures were determined by spectroscopic evidences. Compound 2 showed moderate cytotoxicity. 相似文献
995.
A novel kind of supported combined liquid membrane(SCLM) has been studied for the Gd(Ⅲ) transfer.SCLM contained polyvinylidene fluoride membrane(PVDF) as the liquid membrane support and renewal solution including HNO3 solution as the stripping solution and 2-ethyl hexyl phosphonic acid-mono-2-ethyl hexyl ester(HEH(EH)P) as the carrier dissolved in kerosene. The mixed solution of carrier and kerosene was membrane solution.The optimum transport conditions of Gd(Ⅲ) were that concentration of HNO3 solution was 4.00 mol/L,concentration of carrier was 0.16 mol/L,and volume ratio of membrane solution to stripping solution was 30:30 of the renewal phase,and pH value was 4.80 of the feed phase.Under the optimum condition studied, when initial concentration of Gd(Ⅲ) was 1.00×10-4 mol/L,the transfer rate of Gd(Ⅲ) was 96.8%during 130 min. 相似文献
996.
A novel fluorescent Zn2+ probe based on 6-methoxyquinolin was synthesized in four steps from inexpensive starting materials.It exhibits very strong fluorescence responses and has a remarkably high selectivity to Zn2+ than other physiological relevant metal ions.This new compound could be used as low-priced yet high-quality Zn2+ probe. 相似文献
997.
2,3-Dihydroquinazolin-4(1H)-one derivatives are synthesized via a one-pot,three component reaction of isatoic anhydride and an aromatic aldehyde with ammonium acetate or primary amine catalyzed by silica-bonded N-propylsulfamic acid(SBNPSA) in refluxing ethanol. 相似文献
998.
999.
可逆加成一断裂链转移(RAFT)聚合作为一种新型活性自由基聚合方法,由于其具有单体适用面广、聚合条件温和、不受聚合方法的限制等优点,已经成为聚合物分子设计的有效手段之一.点击化学(Click chaemistry)是近几年发展起来的一种快速合成的新方法,是指选用易得原料,通过可靠、高效而又具有选择性的化学反应来实现碳杂... 相似文献
1000.