in this thesis, a better reaction conditions for the synthesis of spirobarbiturates catalyzed by task-specific ionic liquid (2-hydroxy-n-(2-hydroxyethyl)-n,n-dimethylethanaminium formate), calcium hypochlorite ca(ocl)2 or n-bromosuccinimide (nbs) in the presence of water at room temperature by ultrasonic technique is provided. the design and synthesis of spirocycles is a challenging task because it involves the creation of a quaternary center, which itself is considered to be one of the most difficult tasks among synthetic transformations. the spirobarbiturates through one-step multicomponent reaction (mcr) of aldehydes, n.n?-dimethylbarbituric acid and catalyst by ultrasonic technique with high efficiency and no side products are produced. this method has advantages compared with previous methods such as simple reaction conditions, short time, the reaction environment safety and ease the separation of synthesis products after the reaction. in the second part of this project a one-pot, three-component condensation of malononitrile and thiols with aromatic aldehydes, containing either electron-donating or electron-withdrawing groups, catalyzed by biguanide-supported sba-15(sba-15-met) in ethanol at temperature 50 ?c conditions to produce highly substituted pyridines in high conversion is reported. also in the third part of this project, an efficient process multi-component reaction of various thiols and malononitrile with aromatic aldehydes, containing either electron-donating or electron-withdrawing groups, catalyzed by ion exchange resin (ion exchange iii) in acetonitrile at room temperature conditions to produce highly substituted pyridines in high conversion is reported.