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
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
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 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
A new efficient synthesis of 2,5,6-trisubstituted oxazolo（5,4-d]pyrimidi-7（6H）-ones by consecutive azaWittig reaction was developed.The sequential three-component reaction of oxazolyliminophosphorane4,isocyanates a...A new efficient synthesis of 2,5,6-trisubstituted oxazolo（5,4-d]pyrimidi-7（6H）-ones by consecutive azaWittig reaction was developed.The sequential three-component reaction of oxazolyliminophosphorane4,isocyanates and amines produced 2,5,6-trisubstituted oxazolo[5,4-d]pyrimidi-7（6H）-ones 7 in good overall yields in the presence of catalytic amount of EtONa.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.
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.
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.
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.
基金financial support of this work by the National Natural Science Foundation of China(No.21172085)the Natural Science Foundation of Hubei Province(No. 2014CFB567)the Open Foundation of Hubei Province Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients
文摘A new efficient synthesis of 2,5,6-trisubstituted oxazolo（5,4-d]pyrimidi-7（6H）-ones by consecutive azaWittig reaction was developed.The sequential three-component reaction of oxazolyliminophosphorane4,isocyanates and amines produced 2,5,6-trisubstituted oxazolo[5,4-d]pyrimidi-7（6H）-ones 7 in good overall yields in the presence of catalytic amount of EtONa.
