Multi-component reactions (MCRs) are very important reactions and they can produce the desire products in one pot without isolating the intermediates and decreasing the reaction times and using energy, therefore, these reactions have attracted more interest in modern organic syntheses and researchers have made great efforts for developing new MCRs In continuation of our effort to develop new and green method in organic chemistry, avoiding using organic solvents during the reactions in organic synthesis. Here we wish to report a an efficient one pot-reaction under clean and economical conditions (green chemistry) with straightforward work-up using inexpensive Br?nsted acidic ionic liquids in short reaction time with high yield. Ionic liquids (ILs) as green solvents and catalysts have been applied frequently in modern organic reactions, due to their specific properties such as high thermal stability, undetectable vapor pressure, non- inflammability and significant advantages in terms of environmental and economic impacts. Br?nsted acidic ionic liquids were designed to replace traditional mineral acidic in chemical procedures. In this investigation N-methyl-2-pyrrolidonum hydrogen sulfate [H-NMP]HSO 4 was synthesis and its application for synthesize of some organic compounds such as: ?-aminonitrils, coumarins, 1-amidoalkyl 2-naphthols. ?–aminonitriles as important intermediates for predation of ?-amino acids and various nitrogen containing heterocycles were investigated. The Strecker reaction is one of the general method for synthesize of ?-aminonitrils, we did apply this useful acidic ionic liquid for synthesis of ?-aminonitrils from coupling various aldehydes and ketones with aniline and trimethylsilyl cyanide under one-pot Strecker reaction, facile and solvent-free conditions. The coumarins are versatile heterocyclic organic compounds which also are known as benzo-2-pyrone derivatives, having various biological activities.Also they have widely used as additives in food. We employed this catalyst in the Pechmann reaction as a well-known simple method from the reaction of phenols and ?-ketoesters at 120 o C under solvent–free conditions in good to excellent yields with short reaction times. Amidoalkyl 2-naphtols as useful compounds bearing 1,3-arrangement of amino and oxygenated functional groups are frequently found in biologically important natural products and also are potent biological activities such as nucleoside antibiotics and HIV protease inhibitors Interestingly the 1-amidomethyl-2-naphthols can be converted to important biologically active 1-aminomethyl-2-naphthol derivatives by an amide hydrolysis reaction. We also prepared these important compounds by mixing various aldehydes with acetamide, benzamide or urea in the presence of catalytic amount of [H-NMP]HSO 4 at 120 o C using an oil bath.