A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxy- carbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of -keto ester, aldehydes and urea through impro...A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxy- carbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of -keto ester, aldehydes and urea through improved Biginelli reaction.展开更多
A novel catalyst indium(Ⅲ) tribromide is shown to efficiently promote 5-carbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones from a three-component coupling of β-diketones, aldehydes and urea in ethanol. This modified on...A novel catalyst indium(Ⅲ) tribromide is shown to efficiently promote 5-carbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones from a three-component coupling of β-diketones, aldehydes and urea in ethanol. This modified one-pot Biginelli′s cyclocondensation not only features simple operation, but also takes place in nonpolluted environment. The structure of the Biginelli reaction product from β-diketones, salicylaldehyde and urea has been proposed to possess an oxygen-bridge.展开更多
Study of the phase chemistry relation of quaternary system system CsBr-SmBr3-(13%)HBr-H2O at 25 ℃ is carried out in order to investigate the reaction of CsBr and SmBr3 in hydrobromic acid. A new compound 5CsBr.2SmBr3...Study of the phase chemistry relation of quaternary system system CsBr-SmBr3-(13%)HBr-H2O at 25 ℃ is carried out in order to investigate the reaction of CsBr and SmBr3 in hydrobromic acid. A new compound 5CsBr.2SmBr3.22H2O is discovered and obtained in the system. X-ray powder diffraction, thermal analysis (TG and DTA) and polarization character of the new compound obtained from the system are investigated.Meanwhile, the synthetic mechanisms of compounds (CsSm2Br7, Cs3Sm2Br9, Cs3SmBr6 and Cs2SmBr5) are suggested on the basis of phase chemical relation of the system.展开更多
Phase chemical relation of quaternary systems KBr-REBr3-HBr (13%)-H2O (25℃, RE=La, Sm) were determined, and the rule of phase change was also discovered bere when RE are light rare earth elements. It is found from th...Phase chemical relation of quaternary systems KBr-REBr3-HBr (13%)-H2O (25℃, RE=La, Sm) were determined, and the rule of phase change was also discovered bere when RE are light rare earth elements. It is found from the experiment that the quaternary systems in which KBr and REBr3 react in hydrobromic acid belong to a simple eutectic type,so the reaction mechanism for synthesizing compound K2REBr5 type and real action of the first step reaction can be explained with Meyer’s method. Furthermore, it can be seen from comparison between the systems in this paper and the system CsBr-REBr-HBr (13%)-H2O (25℃) that CsBr and REBr3 acting in hydrobromic acid with each other can form doublecompound easier than KBr and REBr3.展开更多
基金the National Natural Science Foundation of China(29872018&29972026).
文摘A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxy- carbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of -keto ester, aldehydes and urea through improved Biginelli reaction.
文摘A novel catalyst indium(Ⅲ) tribromide is shown to efficiently promote 5-carbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones from a three-component coupling of β-diketones, aldehydes and urea in ethanol. This modified one-pot Biginelli′s cyclocondensation not only features simple operation, but also takes place in nonpolluted environment. The structure of the Biginelli reaction product from β-diketones, salicylaldehyde and urea has been proposed to possess an oxygen-bridge.
文摘Study of the phase chemistry relation of quaternary system system CsBr-SmBr3-(13%)HBr-H2O at 25 ℃ is carried out in order to investigate the reaction of CsBr and SmBr3 in hydrobromic acid. A new compound 5CsBr.2SmBr3.22H2O is discovered and obtained in the system. X-ray powder diffraction, thermal analysis (TG and DTA) and polarization character of the new compound obtained from the system are investigated.Meanwhile, the synthetic mechanisms of compounds (CsSm2Br7, Cs3Sm2Br9, Cs3SmBr6 and Cs2SmBr5) are suggested on the basis of phase chemical relation of the system.
文摘Phase chemical relation of quaternary systems KBr-REBr3-HBr (13%)-H2O (25℃, RE=La, Sm) were determined, and the rule of phase change was also discovered bere when RE are light rare earth elements. It is found from the experiment that the quaternary systems in which KBr and REBr3 react in hydrobromic acid belong to a simple eutectic type,so the reaction mechanism for synthesizing compound K2REBr5 type and real action of the first step reaction can be explained with Meyer’s method. Furthermore, it can be seen from comparison between the systems in this paper and the system CsBr-REBr-HBr (13%)-H2O (25℃) that CsBr and REBr3 acting in hydrobromic acid with each other can form doublecompound easier than KBr and REBr3.
