A facile synthesis of pyrimido2',3':5',1'pyrazolo 3',4':4,5pyrimido1,6-abenzimidazoles and 1,2,4triazino3',4':5',1'pyrazolo3',4':4,5-pyrimido6,1-abenzimidazoles

摘要

Thieno2',3':4,5pyrimido1,6-abenzimidazoles 4-7 have been synthesized by the reaction of 3-mercaptopyrimido1,6-abenzimidazole with halo ketones and halo esters, respectively. 3-Aminopyrazolo3',4':5,6pyrimido1,6-abenzimidazole 9 reacted with acetylacetone, ethyl acetoacetate, ethyl benzoylacetate, ethyl #alpha#-chloroacetoacetate and #beta#-aryl-#alpha#-cyanoacrylonitriles to give pyrimido2",3":5',1'pyrazolo3'4':4,5pyrimido1,6-abenzimidazoles 13,14a,b 15, 19a-e, respectively. Diazonium salt 20 coupled with each of malononitrile, benzoylacetonitrile, ethyl cyanoacetate, acetylacetone, diethylmalonate and #beta#-keto esters to give 1,2,4triazino3",4":5',1'pyrazolo3'4':4,5pyrimido6,1-abenzimidazoles 21-25a,b, respectively. Structures of the synthesized compounds are confirmed on the basis of elemental analyses, and spectral data.