Utility of 4‐Benzylidene‐2‐phenyl‐5(4H)‐oxazolone in Synthesis of Triazine, Oxadiazole and Imidazole Derivatives of Anticipated Biological Activity

Abstract

Treatment of oxazolone 1 with hydrazine hydrate at room temperature gave the (Z)‐configurated isomer hydrazide (Z)‐3 (high yield). However, refluxing 1 with hydrazine hydrate yielded the (E)‐configurated isomer hydrazide (E)‐2 (low yield).The hydrazide derivative (Z)‐3 has been utilized as synthon for the synthesis of 1,2,4‐triazinone, imidazolone, and oxadiazole derivatives through appropriate routes. The thiosemicarbazide and semicarbazide derivatives are synthesized by different routes. The structures of the new compounds were established on the basis of IR, 1H‐NMR, mass spectral data, and elemental analysis.

Reaction of 2‐Phenyl‐4‐arylidene‐1,3‐oxazolones with Different Nucleophiles for Synthesis of Some New Heterocycles

“…Treatment of 2‐phenyl‐4‐(thiophen‐2‐ylmethylene)oxazol‐5(4 H )‐one ( 1b ) with hydrazine hydrate in refluxing ethanol for 3 h afforded the hydrazide derivative ( 9 ) . However, on doing the same reaction in methanol by refluxing for 1 h, we get the pyrazolidinone derivative ( 10 ) (cf.…”

“…A solution of ( 1b ) (0.005 mol) in ethanol (20 mL) and hydrazine hydrate (0.01 mol) was refluxed on a water bath for 3 h. The solvent was evaporated, and the residue was treated with cold water (30 mL). The solid product was filtered off and recrystallized to give (3‐hydrazinyl‐3‐oxo‐1‐(2‐thienyl)‐1‐en‐2‐yl)benzamide ( 9 ), (93% yield), white powder (from ethanol), mp 138–140°C .…”

Design, Synthesis, and Evaluation of the Anticancer Properties of a Novel Series of α‐(Benzoylamino)‐β‐substituted Acrylic Amide Derivatives of Pyrazolo[1,5‐a]pyrimidine

“…The second type involves the ring expansion to obtain triazinones . The third one involves the ring opening of oxazolones to obtain α‐(benzoylamino)‐β‐substituted acrylic amides .…”

Action of Some Nitrogen and Carbon Nucleophils on 4‐Arylidene‐1,3‐oxazolones

“…The action of hydrazine hydrate on different oxazolones in different conditions was previously studied [9][10][11][12], but the stereochemistry of the product obtained was not discussed. Thus, treatment of 1 with hydrazine hydrate in refluxing ethanol afforded the Econfigurated isomer hydrazide derivative (E) 3a (low yield).…”