81819-85-4

Upstream product

• 118-93-4 o-hydroxyacetophenone 
• 123-11-5 4-methoxy-benzaldehyde 
• 34000-29-8 [E]-3-(p-methoxyphenyl)-1-(2-hydroxyphenyl)prop-2-en-1-one 
• 100-63-0 phenylhydrazine 
• 3327-24-0 1-(2-hydroxyphenyl)-3-(4-methoxyphenyl)-2-propen-1-one 
• 39729-17-4 2'-hydroxy-4-methoxychalcone dibromide 
• 59-88-1 phenylhydrazine hydrochloride 

Downstream Products

• 83548-80-5 2-[4-Bromo-5-(4-methoxy-phenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl]-phenol 

Relevant academic research and scientific papers

Investigating ESIPT and donor-acceptor substituent effects on the photophysical and electrochemical properties of fluorescent 3,5-diaryl-substituted 1-phenyl-2-pyrazolines

This paper describes the synthesis, structural study, and evaluation of electrochemical and photophysical properties by UV–Vis absorption and fluorescence emission analysis (solution and solid-state) of a series of eight 3,5-aryl-substituted 1-phenyl-2-pyrazolines (5), where 3-aryl = 2-OH-C6H4 (5a-g) or Ph (5h), and 5-aryl = Ph (a, h), 1-naphthyl (b), 4-Br-C6H4 (c), 4-F-C6H4 (d), 4-OCH3-C6H4(e), 4-NO2-C6H4 (f), 4-(N(CH3)2)-C6H4(g). The UV–Vis absorption properties of 2-pyrazolines were evaluated in DCM, MeCN, AcOEt, EtOH, and DMSO as the solvent and showed a fluorescence shift for the polar aprotic solvents. The steady-state fluorescence emission exhibited a band in the blue region when excited at the least energetic transition of each compound, although the excited-state intramolecular proton (ESIPT) effect was not detected. In the solid state, compounds presented similar behavior regarding absorption and emission properties compared to the solution assays. With the electrochemical analyses performed for the synthesized 2-pyrazolines, it was possible to conclude that the redox potentials were influenced by the electronic and steric effects of the substituents on the aryl rings and, according to the electronic nature of the substituents, which electron-donating groups were favored. Finally, the TD-DFT analyses revealed that all compounds had delocalized electron density throughout the 2-pyrazolines unit and were not influenced by the substituent bonded at C-5. Nonetheless, LUMO orbital analysis showed that only derivatives 5b and 5f have this localized density over the substituents.

Synthesis of pyrazoline and isoxazoline in triethanolamine medium

Reactions of chalcones 1a-u with phenylhydrazine and hydrazine hydrate give pyrazolines 2a-u and with hydroxylamine hydrochloride yield isoxazolines 3a-c in triethanolamine medium. The structures of products are established by melting points, chemical studies and spectral data (IR and 1HNMR).

CONDENSATION REACTIONS OF 1,3-DIPHENYL-2-PROPEN-1-ONES WITH NUCLEOPHILIC REAGENTS

The reactivity of substituted 1,3-diphenyl-2-propen-1-ones has been investigated under acidic and basic conditions with amino-compounds resulting to heterocyclic derivatives.Other reactions with ethyl acetoacetate and acetylacetone have afforded substitut

Action of Phenylhydrazine Hydrochloride on Chalkone Dibromides in Dimethylformamide

Chalkone dibromides (II) when treated with phenylhydrazine hydrochloride in DMF do not give the expected pyrazoles, but afford 3,5-diaryl-1-phenylpyrazolines (III) which are the normal products of chalkones (I) and phenylhydrazine hydrochloride in DMF.