Download (4Mb) - Etheses - Saurashtra University

Part-IResults and Discussion3.3 Condensation of 2-chloromethylpyrimidin-4(3H)-ones and 2-mercaptobenz-imidazoles to get corresponding condensed pyrimidinylmethylthiobenzimidazoles(IIIi-xxxv)The appropriate condensed 2-chloromethylpyrimidines-4(3H)-one IIi-xviii werecondensed with the 2-mercaptobenzimidazole and 2-mercapto-5-methoxy 27benzimidazole under basic conditions. Literature reports indicate use of NaOMe/MeOHas one of the preferred reaction condition for this condensation. However, it was decidedto utilize the green chemical, eco-friendly technique of Phase Transfer Catalysis (PTC),which involved aq. NaOH (10%) and methylene dichloride as two phases. TriethylBenzylammonium Chloride (TEBA.Cl) was the PTC employed. The reaction was facileat stirring condition at RT within an hour; the product was formed completely and inexcellent yield and purity (Scheme-19).OHNNH+HSNIIi-xviiiClN27Y = H, OCH 3TEBAAq. NaOH (10%)YONHNSNIIIi-xxxvScheme-19HNYThe proposed mechanism is as follows (Scheme-20):84