35220-92-9Relevant academic research and scientific papers
Regioselectivity in the Reaction of 2-Aminobenzothiazoles and 2-Aminobenzimidazoles with Enaminonitriles and Enaminones: Synthesis of Functionally Substituted Pyrimido[2,1-b][1,3]benzothiazole and Pyrimido[1,2-a]benzimidazole Derivatives
Alnajjar, Abdulaziz,Abdelkhalik, Mervat Mohammed,Riad, Hossam Mohammed,Sayed, Samia Mohammed,Sadek, Kamal Usef
, p. 2760 - 2765 (2018)
A variety of new polyfunctionally substituted benzo[d]pyrimido[2,1-b][1,3]thiazole and benzo[4,5]imidazo[1,2-a]pyrimidine derivatives have been synthesized. The general synthetic procedure used for this purpose involves the condensation of 2-aminobenzothiazole and 2-aminobenzimidazole with a variety of enaminonitriles, enaminones, and acrylaldehyde. The regioselectivity for initial attack of either endocyclic ring nitrogen or exocyclic amino group was studied and rationalized for. It has been concluded that ring nitrogen is the most reactive cite in acidic medium, and cyclic intermediate can also be isolated, attesting to this conclusion upon cyclization. However, in basic or neutral medium, the exocyclic amino group was found to be the most reactive center. All structures of the newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible.
Synthesis of structurally related purines: Benzimidazo[1,2-a]pyridines, benzimidazo-[1,2-c]pyrimidines, and pyrazolo-[1,5-a]pyrimidines
Elgemeie, Galal H.,Metwally, Nadia H.
, p. 779 - 785 (2000)
Reactions of sodium salts of 3-hydroxymethylene-2-alkanones with 2-cyanomethylbenzimidazole afforded benzimidazo[1,2-a]pyridines. Analogues reactions with 2-aminobenzimidazole and 5-aminopyrazoles afforded benzimidazo[1,2-c]pyrimidines and pyrazolo[1-5-a]pyrimidines.
A Simple Regioselective Synthesis of Pyrimidobenzimidazoles
Tseng, Shin-Shyong,Epstein, Joseph W.,Brabander, Herbert J.,Francisco, Gerardo
, p. 837 - 843 (2007/10/02)
2-Aminobenzimidazoles were reacted with enaminones in acetic acid to give pyrimidobenzimidazoles.With a substituted enaminone only one regioisomer was obtained.Structural assignments based on nmr and uv spectroscopy are presented.Possible pathways
