A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

Thiazoles and benzothiazoles form part of the molecular structure of many drugs, biocides and industrial chemicals. Examples include 2-mercaptobenzothiazole which is widely used as a rubber accelerator in the manufacture of tyres and which as a consequence occurs in street runoff and esturine sediments [ l ] and which may have ecotoxicological importance. In spite of this widespread occurrence ...