One Pot Synthesis of Dihydropyrano (2,3-c) pyrazoles Catalyzed by Bronsted Acid

An efficient and versatile multicomponent procedure for the synthesis dihydropyrano (2, 3-c) pyrazole derivatives promoted by Bronsted Acid as a catalyst is PTSA in protic solvent and These derivatives can be obtained series of dihydropyrano (2,3-c)pyrazoles from ethyl acetoacetate, hydrazine hydrochloride, malononitrile, and aromatic aldehydes in the presence of PTSA. This method was is used for environmentally friendly multicomponent cyclocondensation methods which have a series of intriguing advantages , including the use of a nontoxic solvent, inexpensive and readily available catalyst, simplicity in work-up, high yields (up to 91%). The compound can be confirmed by 1HNMR, 13CNMR and LCMS. Besides, the study of the antimicrobial activity was against bacterial as well as fungal strains. KEYWORDS: Ethyl acetoacetate, hydrazine hydrochloride, malononitrile, aromatic aldehydes, Dihydropyrano (2, 3-c) pyrazoles, PTSA