A rapid and efficient method for the synthesis of isoxazolo[5,4-d]pyrimidin-4（5H）-ones has been developed through cyclocondensation of 5-aminoisoxazole-4-carboxamides with orthoesters under conventional heating and ...A rapid and efficient method for the synthesis of isoxazolo[5,4-d]pyrimidin-4（5H）-ones has been developed through cyclocondensation of 5-aminoisoxazole-4-carboxamides with orthoesters under conventional heating and solvent-free microwave irradiation with solid acid catalysis. In comparison, the reactions are faster and the yields are higher under microwave irradiation.展开更多
2, 7-Diaminothieno[2, 3-d：5, 4-d]dipyrimidine-4, 5（3H, 6H）diones 4 were synthesized by a facile synthetic method, which includes bis-aza-Wittig reaction of bis-iminophosphorane 1 with aromatic isocyanate to give bi...2, 7-Diaminothieno[2, 3-d：5, 4-d]dipyrimidine-4, 5（3H, 6H）diones 4 were synthesized by a facile synthetic method, which includes bis-aza-Wittig reaction of bis-iminophosphorane 1 with aromatic isocyanate to give bis-carbodiimide 2 and subsequent reaction of 2 with various dialkylamine in the presence of solid K2CO3 or EtONa.展开更多
A novel method to synthesize 2,6-bis(p-aminophenyl)benzo\[1,2-d;5,4-d'\]bisoxazole using 1,2,3-trichlorobenzene as the starting material through nitration, substitution, hydrogenation, and condensation was reporte...A novel method to synthesize 2,6-bis(p-aminophenyl)benzo\[1,2-d;5,4-d'\]bisoxazole using 1,2,3-trichlorobenzene as the starting material through nitration, substitution, hydrogenation, and condensation was reported. During the condensation, the influence of the amount of SnCl_2 on the yield of the product was studied. The electron spectra of the compound were discussed, the results showed that it is a fluorescence material with large Stokes shift.展开更多
Twenty-seven oxadiazolino[5,4-d][1,5]benzodiheteropine derivatives have been synthesized by the 1,3-dipolar cycloaddition of benzodiheteropines with nitrile oxide 1,3-dipoles,their conformations and the characteristic...Twenty-seven oxadiazolino[5,4-d][1,5]benzodiheteropine derivatives have been synthesized by the 1,3-dipolar cycloaddition of benzodiheteropines with nitrile oxide 1,3-dipoles,their conformations and the characteristics of the newly formed oxadiazoline fused on them have been studied.It has also been found that the mass spectra show characteristic fragmentation patterns.展开更多
A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse is...A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse isocyanates in the presence of sodium hydride. The easy availability of substrates and tolerance of structural diversity in this reaction make it attractive to be used for construction of libraries in drug discovery process.展开更多
文摘A rapid and efficient method for the synthesis of isoxazolo[5,4-d]pyrimidin-4（5H）-ones has been developed through cyclocondensation of 5-aminoisoxazole-4-carboxamides with orthoesters under conventional heating and solvent-free microwave irradiation with solid acid catalysis. In comparison, the reactions are faster and the yields are higher under microwave irradiation.
基金We gratefully acknowledge financial support of this work by the National Key Project for Basic Research(2003CB114400,2003CB114406)the National Natural Science Foundation of China(Project No.20372023 and 20102001).
文摘2, 7-Diaminothieno[2, 3-d：5, 4-d]dipyrimidine-4, 5（3H, 6H）diones 4 were synthesized by a facile synthetic method, which includes bis-aza-Wittig reaction of bis-iminophosphorane 1 with aromatic isocyanate to give bis-carbodiimide 2 and subsequent reaction of 2 with various dialkylamine in the presence of solid K2CO3 or EtONa.
文摘A novel method to synthesize 2,6-bis(p-aminophenyl)benzo\[1,2-d;5,4-d'\]bisoxazole using 1,2,3-trichlorobenzene as the starting material through nitration, substitution, hydrogenation, and condensation was reported. During the condensation, the influence of the amount of SnCl_2 on the yield of the product was studied. The electron spectra of the compound were discussed, the results showed that it is a fluorescence material with large Stokes shift.
文摘Twenty-seven oxadiazolino[5,4-d][1,5]benzodiheteropine derivatives have been synthesized by the 1,3-dipolar cycloaddition of benzodiheteropines with nitrile oxide 1,3-dipoles,their conformations and the characteristics of the newly formed oxadiazoline fused on them have been studied.It has also been found that the mass spectra show characteristic fragmentation patterns.
基金supported by the National Natural Science Foundation of China(No.30500634) and NSF of Beijing (No.7102112)
文摘A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse isocyanates in the presence of sodium hydride. The easy availability of substrates and tolerance of structural diversity in this reaction make it attractive to be used for construction of libraries in drug discovery process.
