Synthesis of 1-substituted 5-aryl-3-(3-coumarinyl)-2-pyrazolines by the reaction of 3-aryl-1-(3-coumarinyl)propen-1-ones with hydrazines

Abstract

Dedicated to Professor Dr. Fritz Sauter on the occasion of his 75 th birthday 1-Acetyl-and 1-propionyl-2-pyrazolines 11-27 have been synthesized by the reaction of (3-coumarinyl)chalcones 1-10 with hydrazine in hot acetic acid or propionic acid. While 5-aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazolines 28-35 have been prepared by the reaction of (3-coumarinyl)chalcones 1,3,5-10 with phenylhydrazine in hot pyridine. Structures of all new compounds have been elucidated by microanalyses, 1 H and 13 C nmr spectroscopies.

On the Mechanism of Photodehydrogenation of Aryl(hetaryl)pyrazolines in the Presence of Perchloroalkanes

“…The synthesis of 3-cinnamoylcoumarins 2a-f. 3-Cinnamoylcoumarins 2a-f were prepared according to (22 The synthesis of (1,5-diaryl-3-pyrazolinyl)coumarins 3a-k. The reactions of 3-cinnamoylcoumarins with phenylhydrazines are described in sufficient detail (26)(27)(28)(29)(30). We have used two protocols for preparation of compounds 3a-k (Scheme 4).…”

Synthesis and pharmacological evaluation of a novel series of 5-(substituted)aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazolines as novel anti-inflammatory and analgesic agents

“…3-Aryl-1-(3-coumarinyl)propan-1-ones (2a-l) were synthesized by the reaction of 3-acetyl coumarin and various substituted aromatic aldehydes in the presence of mixture of piperidine and glacial acetic acid. 5-(Substituted)aryl-3-(3-coumarinyl)-1-phenyl-2-pyrazoline compounds (3a-l) were obtained in good yields by reacting 3-aryl-1-(3-coumarinyl)propan-1-ones (2a-l) with phenylhydrazine in hot pyridine [19].…”

“…On this basis, Levai et al [19] have recently described only the synthesis of 1-substituted-5-aryl-3-(3-coumarinyl)-2-pyrazolines by the reaction of (3-coumarinyl)-chalcones and hydrazines. In view of these observations and in continuation of our research programme on the synthesis of heterocyclic compounds [20][21][22][23], we report herein the synthesis of some new 2-pyrazoline derivatives, which have been found to possess an interesting profile of anti-inflammatory, analgesic and antipyretic activities along with significantly less ulcerogenic potential.…”

Five‐Membered Heterocycles: 1,2‐Azoles. Part 1. Pyrazoles

“…The formation of 225 involves a decarboxylation process, not observed in the reaction of compound 219a with hydrazine [215]. 3-Aryl-1-(3-coumarinyl)propen-1-ones also react with hydrazines to afford 1-substituted 5-aryl-3-(3-coumarinyl)-2-pyrazolines [217].…”