An efficient and stereoselective synthesis of pyrazolo[4,3‐c]pyridine derivatives under microwave heating

Abstract

A practical, inexpensive, and rapid method for the stereoselective synthesis of pyrazolo [4,3-c]pyridine derivatives via microwave-assisted reactions of 3,5-diarylidenepiperidin-4-ones with phenylhydrazine in ethylene glycol. This method has the advantages of good yield, operational simplicity, and simple purification procedure.

A mild, simple, and efficient approach to the synthesis of some novel 7-benzylidene-2,3-diphenyl-3,3a,4,5,6,7-hexahydro-2H-indazole derivatives

“…For this purpose, we create a method for the synthesis of some novel 7-benzylidene-2,3-diphenyl-3,3a,4,5,6,7-hexahydro-2H-indazole derivatives, which is environmentally benign, simple and economical by introducing DABCO, a tertiary amine base with weak basicity and moderate hindrance (14), as a nontoxic, nonvolatile, stable, inexpensive and easy to handle catalyst. Also this reaction requires neither solvents nor harmful reagents.…”

“…Most of these methods provided the procedure of synthesizing 7-benzylidene-5-methyl-2,3-diphenyl-3,3a, 4,5,6,7-hexahydro-2H-pyrazolo[4,3-c]pyridine derivatives (13)(14)(15) and meanwhile only a limited number of 7-benzylidene-2,3-diphenyl-3,3a,4,5,6,7-hexahydro-2H-indazole derivatives have been synthesized (12,13). However, for the most of these methods, the yield is low due to reverse and side reactions, and several and difficult purification steps are required.…”

One‐Pot Microwave‐Assisted Synthesis of Novel Substituted N‐Dichloroacetyl‐4,5‐dimethyl‐1,3‐oxazolidines

“…Since the first study on the use of microwave irradiation in organic chemistry, the accelerated process has been a lure for chemists to further apply this technology to new reactions. Microwave‐assisted reactions have received great interest because of their simplicity in operation, enhanced reaction rates, products with high purity, and better yields compared to those conducted by conventional heating [1,2]. Therefore, microwave‐assisted synthesis has been used as an effective and powerful technique to promote a lot of chemical reactions [3–6].…”