Eco-friendly synthesis and biological evaluation of substituted pyrano[2,3-c]pyrazoles

Convenient Synthesis, Characterization, Cytotoxicity and Toxicity of Pyrazole Derivatives

“…Thus, 1 H NMR spectrum of 4a revealed the presence of a singlet at δ 2.49 ppm indicating the presence of the CH 3 group, a multiplet at δ 7.59-8.41 ppm equivalent to the C 6 H 5 group and a singlet at δ 10.40 ppm corresponding to the NH group. Moreover the 13 C NMR spectrum demonstrated a signal at δ 14.1 equivalent to the CH 3 group, δ 116.0 corresponding to the CN group, signals at δ 128. 6, 129.5, 129.7, 129.8, 131.3, 131.8, 133.0, 133.9 corresponding to the phenyl, pyran and pyrazole carbons and a signal at δ 155.7 corresponding to C=O.…”

“…H NMR spectrum of 22a (as an example) showed the presence of a singlet at δ 2.49 ppm corresponding to CH 3 group, a mutiplet at δ 7.09-7.50 ppm corresponding to the phenyl protons and a singlet at δ 9.75 equivalent to the NH group. Moreover, the 13 C NMR spectrum showed the presence of the CH 3 group at δ 12.27, the The methylene group present in the pyrazole 1 was reported to show high reactivity towards thiazole formation via its reaction with phenylisothiocyanate in basic DMF solution followed by heterocyclization with α-halocarbonyl compounds. 28,29 Thus, 1 was reacted with phenylisothiocyanate in DMF/KOH solution to give the intermediate potassium sulfide salt 23.…”

“…The one-pot reaction of compound 1 with salicylaldehyde and malononitrile gave the annulated 5-amino-1-methyl-3H-chromeno[4',3':4,5]-pyrano[2,3-c]pyrazol-6(11bH)-one (13). The analytical and spectral data of the latter product was the basis of its structural elucidation.…”

“…Moreover, 13 C NMR showed signals at δ 36.9 indicating the pyran C-4 and signals at δ 114.1, 127.1, 128.3, 129.1, 137.3, 144.9, 146.8, Kamel: Convenient Synthesis, Characterization, ... 148. 4, 150.6, 154.3, 154.0 equivalent to the phenyl, pyrazole, pyran and pyridine carbons.…”

“…11,12 It has been found that pyranopyrazoles are an important class of biologically active heterocycles. They are reported to possess a multiplicity of pharmacological properties including anticancer, 13 antimicrobial, 14 anti-inflammatory, 15 insecticidal and molluscicidal activities. 16,17 They are also potential inhibitors of human Chk1 kinase.…”