Efficient synthesis of fused pyrazoles via simple cyclization of o-alkynylchalcones with hydrazine

The synthesis of pyrazole derivatives from o-alkynylchalcones and hydrazine via simple cyclization is described. This greener synthetic methodology provides a straightforward approach to the synthesis of a variety of pyrazole derivatives under mild reaction condition. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.