An efficient method is described for the synthesis of 2-substituted quinolino[7＇,8＇：5~6]pyrano[2,3-d] pyrimidin-4（3H）-ones（6） via a tandem aza-Wittig annulation process. The iminophosphorane（3） reacted with a...An efficient method is described for the synthesis of 2-substituted quinolino[7＇,8＇：5~6]pyrano[2,3-d] pyrimidin-4（3H）-ones（6） via a tandem aza-Wittig annulation process. The iminophosphorane（3） reacted with aromatic isocyanates, followed by heterocyclization on the addition of secondary amines, phenols or alcohols to give the corresponding guanidine intermediates（5）, which were cyclized in the presence of a catalytic amount of a base to tetracyclic compounds 6 in good yields. The corresponding carbodiimide（4） and guanidine-type intermediate compounds 5 need not be isolated.展开更多
Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane derivatives 3.Reacting 3 with phenylisocyanate gave the high...Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane derivatives 3.Reacting 3 with phenylisocyanate gave the highly reactive carbodiimide intermediate 4,which was reacted with different nitrones to afford new l,2,4-oxadiazolidin-5-ylidene-aminothiophenes 5a-c. Treatment of 4 with absolute EtOH at room temperature gave methyleneamino-5-（methylthio）thiophene 7,（methylthio）-3-（3- phenylureidothiophene）-2-carboxylate 8 or thienopyrimidine 9 and 10 at refluxing temperature.Finally reaction of carbodiimide intermediate 4 with different secondary amines gave the new thienopyrimidines 11a-c.展开更多
基金Supported by the Mid-young Scholar's Science and Technology Program of the Education Department of Hubei Province,China(No.Q20082202)
文摘An efficient method is described for the synthesis of 2-substituted quinolino[7＇,8＇：5~6]pyrano[2,3-d] pyrimidin-4（3H）-ones（6） via a tandem aza-Wittig annulation process. The iminophosphorane（3） reacted with aromatic isocyanates, followed by heterocyclization on the addition of secondary amines, phenols or alcohols to give the corresponding guanidine intermediates（5）, which were cyclized in the presence of a catalytic amount of a base to tetracyclic compounds 6 in good yields. The corresponding carbodiimide（4） and guanidine-type intermediate compounds 5 need not be isolated.
文摘Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane derivatives 3.Reacting 3 with phenylisocyanate gave the highly reactive carbodiimide intermediate 4,which was reacted with different nitrones to afford new l,2,4-oxadiazolidin-5-ylidene-aminothiophenes 5a-c. Treatment of 4 with absolute EtOH at room temperature gave methyleneamino-5-（methylthio）thiophene 7,（methylthio）-3-（3- phenylureidothiophene）-2-carboxylate 8 or thienopyrimidine 9 and 10 at refluxing temperature.Finally reaction of carbodiimide intermediate 4 with different secondary amines gave the new thienopyrimidines 11a-c.
