Studies with 3‐functionally substituted 2‐arylhydrazononitriles: A new route to 3‐substituted‐2‐arylhydrazononitriles, 4‐amino‐pyrazole‐5‐carbonitriles, azadienes and cinnolines

Abstract

3‐Amino‐3‐phenyl‐2‐phenylazoacrylonitrile 6 is obtained in good yield via reaction of 5 with phenyl magnesium bromide. The compound 6 is readily converted into 4a. The so formed alkanenitrile reacted with phenylmagnesium bromide to yield 8. Compound 8 could be also obtained from reaction of 9 with phenylmagnesium bromide. The arylhydrazononitriles 8 and 4a reacted with chloroacetonitrile to yield the 4‐aminopyrazoles 12a,b. Compound 12a reacted with acetic anhydride to yield the 15a and with benzoyl chloride to yield the pyrazole 16 which was converted into 15b. Refluxing 10 in acetic acid gave a mixture of the azadiene 21 and the cinnoline 22 is obtained. The azadiene 21 is converted into 22 either thermally or photochemically.

Substituted Hydrazonals as Building Blocks in Heterocyclic Synthesis: A New Route to Arylhydrazonocinnolines

“…1,2 The structure and chemistry of these novel arylhydrazones has attracted much attention with plenty of uses for these compounds being reported recently. 3,4 It has been noted that in DMSO these molecules exist as a mixture of two conformers E and Z. 2,5 Since 2-arylhydrazonopyrovales undergoes rearrangement into the 1-arylhydrazono-2-oxopropanes under mild conditions, we thought that it might be possible that such a rearrangement might also take place in the case of 2.…”

Analogs of biologically active compounds IX. Synthesis of several new uracil and pteridine 6-aza-analogs based on cyclization of arylhydrazones derived from mesoxalic acid

“…25 In this reference only phenyl derivative 8o was prepared and referred to as azo compound 8B. On basis of NMR spectroscopy we found that the newly prepared compounds 8i-8p in either DMSO-d 6 or CDCl 3 solutions exist in several tautomeric forms 8Ax-y and 8Bx-y in an equilibrium.…”

Green Synthesis, Printing Performance, and Antibacterial Activity of Disperse Dyes Incorporating Arylazopyrazolopyrimidines

“…3–5 Nitriles have been broadly used as intermediates in the synthesis of various heterocycles, such as aminopyrazoles, that can be easily prepared by the reaction of nitrile derivatives with hydra-zine. 6,7 The reaction of aminopyrazole derivatives with electrophilic reagents affords a variety of fused heterocycles with a broad spectrum of antimicrobial activity. 8–14 Furthermore, these fused heterocycles are also used as intermediates in the dye industry.…”