الفهرس 
Synthesis of Pyrano[2,3-c]pyrazolesOnly 14 pages are availabe for public view
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Abstract
The first chapter is the introduction which comprises an updated
literature survey on the chemistry and biological application of pyrano[2,3-
c]pyrazole derivatives. This review included the design and synthetic
strategies used to obtain the pyrano[2,3-c]pyrazole derivatives, and their
reactions are reviewed and discussed.
The second chapter presented all the experimental procedures used in the
development of the current study, including synthetic methodologies,
physico-chemical properties, biological applications studies (including antiCoV-229E and anticancer assays), and molecular modeling studies of the
synthetic pyrano[2,3-c]pyrazole derivatives.
The third chapter is devoted to results and discussion, which includes a
base-catalyzed one-pot four-component approach was conducted
conventionally or using microwave or ultrasound to synthesize 6-amino-3-
methyl-4-(thiophen-2-yl)-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile
(A) in 93% yield depending on a clean method of simple conditions to adopt
the principles of green chemistry. This could be easily accomplished by
tandem Knoevenagel condensation/Michael addition/imine–enamine
tautomerism/O-cyclization through the reaction of hydrazine hydrate, 96%,
β-keto ester as ethyl acetoacetate, thiophene-2-carbaldehyde, and enolizable
active methylene compound as malononitrile in the presence of piperidine as
a catalyst (5 mol%) with vigorous stirring in an aqueous medium for 20 min
at room temperature under an open atmosphere (conventionally) (Scheme 1).