10557-78-5

Upstream product

• 59305-66-7 (Z)-2-Bromo-1,3-diphenyl-propenone oxime 
• 870127-38-1 (Z)-1,3-diphenylprop-2-yn-1-one O-methyl oxime 
• 7338-94-5 1,3-diphenyl-2-propynone 
• 6502-38-1 chalcone oxime 
• 29881-14-9 1,2-diphenyl-cyclopropane 
• 1474-24-4 1,3-diphenyl-2-triphenylphosphoranylidenepropane-1,3-dione 
• 24768-82-9 4-iodo-3,5-diphenylisoxazole 
• 2039-49-8 3,5-diphehylisoxazole 

Downstream Products

• 22020-72-0 triphenylizoxazole 

Relevant academic research and scientific papers

13C NMR spectroscopy of heterocycles: 3,5-diaryl-4-bromoisoxazoles

A series of 3,5-diarylisoxazoles (1-9) underwent reaction with N-bromosuccinimide in acetic acid to yield the corresponding 3.5-diaryl-4-bromoisoxazoles (1Br-9Br) in low to moderate yield. The X-ray structure of 3-(4-chlorophenyl)-5-phenyl-4-bromoisoxazole showed torsion angles of ~40° and ~36° between the 3- and 5-aryl groups and the central ring system, respectively. Molecular modeling studies predicted the 3,5-phenylisoxazole ring system to be essentially coplanar and the 3,5-diphenyl groups of the 4-bromoisoxazole derivative to be twisted with torsional angles of 50° and 37°, respectively. Carbon-13 nuclear magnetic resonance (13C NMR) data of the 3,5-diaryl-4-bromoisoxazoles were obtained in dimethyl sulfoxide-d6 (DMSO-d6) at 50°C. Plots of the C4 chemical shift data for isoxazoles (1-9) vs. those for 4-bromoisoxazoles (1Br-9Br) showed a good linear correlation (r2 = 0.974) with a slope of 0.96. Substitution on the 3-aryl group had essentially no effect on the chemical shift for C4 of the 4-bromoisoxazole, whereas that on the 5-aryl group showed an excellent correlation with σ+ values. Despite the predicted torsion angle differences, distal transmission of substituent effects in the 4-bromo ring system was essentially analogous to that in the planar 3,5-diarylisoxazoles.

Reactivity of 2-halo-2H-azirines. Part II. Thermal ring expansion reactions: Synthesis of 4-haloisoxazoles

The thermolysis of haloazidoalkenes and 2-halo-2H-azirines is described. 2-Benzoyl-2-halo-2H-azirine-3-carboxylates (2a and 2b) underwent ring expansion leading to the synthesis of new 4-haloisoxazoles in high yield. The same isoxazoles were also obtained in high yield directly from haloazidoalkenes (1a and 1b). The thermolysis of the β-azido-α,β-unsaturated ketone 1e led to complete conversion to form the corresponding isoxazole 4e. An isoxazole derivative 4c could also be obtained, in moderate yield, from 2-bromo-3-phenyl-2H-azirine-2-carboxylate (1c). From the thermolysis of azidoalkene 1d the only product that could be isolated was pyrazine-2,3,5,6-tetracarboxylate (5).

R4NHal/NOHSO4: A Usable System for Halogenation of Isoxazoles, Pyrazoles, and beyond

A new convenient and versatile halogenating system (R4NHal/NOHSO4), giving straightforward and general access to halogenated 3,5-diaryl- and alkylarylisoxazoles, pyrazoles and electron-rich benzenes from the corresponding scaffolds, is suggested. The method provides excellent regioselectivity, scalability to the gram scale, and a broad scope for both aromatics and halogens. A three-step, one-pot reaction protocol was developed, and a series of 3,5-diaryl-4-haloisoxazoles has been efficiently synthesized from 1,2-diarylcyclopropanes under suggested nitrosating-halogenating conditions.

Copper-catalyzed aerobic oxidative C-O bond formation for the synthesis of 3,5-disubstituted isoxazoles from enone oximes

A direct access to 3,5-disubstituted isoxazoles has been accomplished through an intramolecular oxidative coupling reaction of enone oximes using a catalytic quantity of Cu(OAc)2. This method features an inexpensive metal catalyst, molecular ox

Isomerizable (: E / Z)-alkynyl- O -methyl oximes employing TMSCl-NCS in chlorinative cyclization for the direct synthesis of 4-chloroisoxazoles

For the first time, 4-chloroisoxazoles are directly synthesized in moderate to excellent yields from (E/Z)-alkynyl-O-methyl oximes via chlorinative cyclization. The synthesis employs the combination of N-chlorosuccinimide (NCS) and chlorotrimethylsilane (

Iron(III) chloride/diorganyl diselenides: A tool for intramolecular cyclization of alkynone O-methyloximes

This report describes the synthesis of 4-organoselenylisoxazoles via FeCl3/RSeSeR-mediated intramolecular cyclization of alkynone O-methyloximes. The optimized conditions allowed the cyclization to proceed at room temperature under ambient atmo

Synthesis of isoxazoles via electrophilic cyclization

(Chemical Equation Presented) A variety of 3,5-disubstituted 4-halo(seleno)isoxazoles are readily prepared in good to excellent yields under mild reaction conditions by the reaction of 2-alkyn-1-one O-methyl oximes with ICI, I2, Br2,

Convenient and improved halogenation of 3,5-diarylisoxazoles using N-halosuccinimides

The convenient C-4 halogenation of 3,5-diarylisoxazoles using N-halosuccinimides (NBS, NCS, or NIS) in acetic acid is described. A strong acid catalyst was required for efficient halogenation of some isoxazoles depending on the substituent on the 5-phenyl ring. Finally, the 4-iodoisoxazoles were found to undergo a novel proto-deiodination upon heating in the presence of H2SO4.

Preparation of 4-Bromo-1-hydroxypyrazole 2-Oxides by Nitrosation of α-Bromo-α,β-unsaturated Ketoximes

Nitrosation of the oximes of 3-bromo-3-penten-2-one, 3-bromo-4-phenyl-3-buten-2-one, and 2-bromo-1,3-diphenyl-2-propen-1-one using sodium nitrite in acetic acid gave low yields of 4-pyrazolone 1,2-dioxides.Nitrosation using butyl nitrite in the presence of copper(II) sulfate and pyridine in aqueous ethanol produced insoluble copper complexes from which 3,5-dimethyl-, 3-methyl-5-phenyl-, and 3,5-diphenyl-4-bromo-1-hydroxypyrazole 2-oxides could be liberated by treatment with dilute potassium hydroxide, filtration, and acidification of the filtrate.High yields wereobtained with the first two oximes, but, presumably due to unfavorable stereochemistry of the oxime, the diphenyl derivative gave a lower yield of the complex, accompanied by 4-bromo- and 4-nitro-3,5-diphenylisoxazole and 4-oximino-3,5-diphenyl-4,5-dihydroisoxazole.

Halogenation of Vinyl Ketoximes. Synthesis of Isoxazoles and Preparation and Silver Ion-Promoted Reactions of 4-Halo-2-isoxazolines

Reaction of several α,β-unsaturated ketoximes with N-bromosuccinimide (NBS) gave isoxazoles, but yields were lower and the reaction less general than a similar transformation using iodine under basic conditions.With β,β-disubstituted oximes, 4-halo-5,5-disubstituted-2-isoxazolines were obtained using NBS, iodine, or N-chlorosuccinimide.Treatment of the 4-bromoisoxazolines with silver acetate or silver nitrate caused either elimination with rearrangement to give isoxazoles or substitution at C-4, depending upon the nature of the substituents at C-5.