3973-90-8Relevant academic research and scientific papers
Acid Catalyzed Direct-Amidation-Dehydrocyclization of 2-Hydroxy-acetophenones to Benzoxazoles by a One-Pot Sustainable Synthesis
Rancan, Elia,Aric, Fabio,Quartarone, Giuseppe,Ronchin, Lucio,Vavasori, Andrea
, p. 939 - 946 (2015/08/06)
A series of 2-methyl-benzoxazoles have been synthesized starting from 2-hydroxy-acetophenones via a one-pot three steps reaction. Hydroxylamonium salt has been used as amidation agent. The reaction occurs with different anions, but the best results is achieved with hydroxylamonium hydrchloride. Despite the number of consecutive stages, the reaction is highly selective. Mild reaction conditions and various solvents can be used, but trifluoroacetic acid is the preferred. Almost, complete recovery of the trifluoroacetic acid can be achieved by vacuum distillation. The role of trifluoroacetic acid, as well as, of the hydroxylamonium salt suggests a cooperative effect leading to high selective formation of 2-methyl-benzoxazoles. Graphical Abstract: One-pot TFA catalyzed synthesis of benzoxazoles starting from 2-hydroxyacetophenones. (Chemical Equation Presented).
One-pot synthesis of benzoxazoles via the metal-free ortho-C-H functionalization of phenols with nitroalkanes
Aksenov, Nicolai A.,Aksenov, Alexander V.,Nadein, Oleg N.,Aksenov, Dmitrii A.,Smirnov, Alexander N.,Rubin, Michael
, p. 71620 - 71626 (2015/09/08)
PPA-activated nitroalkanes are employed in the design of a one-pot cascade transformation involving metal-free and oxidant-free direct ortho-C-H functionalization, followed by Beckman rearrangement and intramolecular cyclocondensation to produce benzoxazoles and benzobisoxazoles directly from easily available phenols.
Benzisoxazole 2-oxides as novel UV absorbers and photooxidation inhibitors
Kociolek, Martin George,Casbohm, Jerry S.
, p. 863 - 867 (2013/10/01)
Compounds with strong absorptions in the ultraviolet (UV) region of the spectrum, particularly the UVA and UVB, have seen much interest as UV screeners or absorbers in a wide variety of commercial products. A series of benzisoxazole 2-oxides have been synthesized and characterized by UV-vis spectroscopy. A number of derivatives have been shown to posses moderate to strong molar absorption coefficients in the UVB range (ca. 300 nm), the strongest being those derived from benzophenones. Three other derivatives containing additional electron withdrawing groups showed strong molar absorption coefficients in the UVA (ca. 340 nm). Solvent effects on the parent derivatives show changes in the molar absorption coefficients with little changes in the λmax values. Preliminary studies of these compounds as potential additives to prevent photooxidation of polystyrene showed considerable inhibition of polymer degradation with the parent unsubstituted benzisoxazole 2-oxide compounds being the most effective. Copyright 2013 John Wiley & Sons, Ltd. A series of benzisoxazole 2-oxides have been shown to posses moderate to strong molar absorption coefficients in the UVB range (ca. 300 nm) and three others with strong absorptions on the UVA (ca. 340 nm). Solvent effects of the parent derivatives show changes in the molar absorption coefficients with little changes in the λmax values. Preliminary studies of these compounds as potential additives to prevent photooxidation of polystyrene showed considerable inhibition of polymer degradation. Copyright
Synthesis of 1,2-benzisoxazole 2-oxides
Kociolek, Martin G.,Hoermann, Olivia
body text, p. 2632 - 2638 (2012/08/08)
(Chemical Equation Presented) A series of 2-hydroxyaryl ketoximes were converted to the corresponding 1,2- benzisoxazole 2-oxides by treatment with iodobenzene diacetate (in acetic acid or methanol) or N-chlorosuccinimide in water. Both methods gave moderate to excellent yields for a variety of substituted oximes under mild conditions within short reaction times. The latter method has the advantages of an aqueous solvent and lack of halogenated organic by-products. Copyright Taylor & Francis Group, LLC.
Microwave-assisted efficient one-step synthesis of amides from ketones and benzoxazoles from (2-hydroxyaryl) ketones with acetohydroxamic acid using sulfuric acid as the catalyst
Madabhushi, Sridhar,Chinthala, Narsaiah,Vangipuram, Venkata Sairam,Godala, Kondal Reddy,Jillella, Raveendra,Mallu, Kishore Kumar Reddy,Beeram, China Ramanaiah
experimental part, p. 6103 - 6107 (2011/11/30)
Efficient one-step method for the synthesis of amides directly from ketones and benzoxazoles from (2-hydroxyaryl) ketones by the reaction of acetohydroxamic acid using sulfuric acid as catalyst was described.
O-acetyl oximes as transformable directing groups for Pd-catalyzed C-H bond functionalization
Neufeldt, Sharon R.,Sanford, Melanie S.
supporting information; experimental part, p. 532 - 535 (2010/05/02)
[Chemical equation presented] O-Acetyl oxlmes serve as effective directing groups for Pd-catalyzed sp2 and sp3 C-H functionalization reactions. The C-H functionalization products can be subsequently transformed Into ortho- or β-functionalized ketones, alcohols, amines, and heterocycles.
Molecular dynamics of cis-1-(2-hydroxy-5-methylphenyl)ethanone oxime and N-(2-hydroxy-4-methylphenyl)acetamide in solution studied by NMR spectroscopy
Mamedov, Ibrahim Garib,Eichhoff, Uwe,Maharramov, Abel Mammadali,Bayramov, Musa Rza,Mamedova, Yegana Vagif
experimental part, p. 671 - 677 (2011/05/30)
The formation of hydrogen bonds and molecular dynamics for themolecules cis-1-(2-hydroxy-5-methylphenyl)ethanone oxime (I) and N-(2-hydroxy-4- methylphenyl)acetamide (II) have been investigated in solution using NMR. The results confirm the formation of O-H...O, O-H...N and O...H-N type inter- and intramolecular hydrogen bonds. Spin-lattice relaxation times (T1), activation energy of molecular dynamics and energy of intramolecular hydrogen bonds have been determined. Copyright
Synthesis, Spectral Data and Extraction of Copper by 1-(2'-Hydroxy-5'-alkylphenyl)-1-alkanone Oximes
Krzyzanowska, Ewa,Olszanowski, A.,Juskowiak, M.
, p. 617 - 630 (2007/10/02)
1-(2'-Hydroxy-5'-alkylphenyl)-1-ethanone oximes with a normal alkyl group containing 2 to 12 carbon atoms and 1-(2'-hydroxy-5'-methylphenyl)-1-alkanone oximes containing 1 to 11 carbon atoms in the hydrocarbon chain were synthesized.Spectral data (u.v., i.r., n.m.r. and 13C) of oximes are reported.Four of these oximes were used for copper extraction from acidic solution.The results obtained indicate, that these oximes are better extractants than alkyl derivatives of 2-hydroxybenzophenone oximes.
Mass Spectra of 1-(2'-Hydroxy-5'-alkylphenyl)-1-alkanone (E)-Oximes
Lozynski, Marek,Krzyzanowska, Ewa
, p. 33 - 40 (2007/10/02)
The mass spectra of 1-(2'-hydroxy-5'-alkylphenyl)-1-ethanone (E)-oximes 1-6 and 1-(2'-hydroxy-5'-methylphenyl)-1-alkanone (E)-oximes 7-12 are given and the major fragmentation pathways discussed.The simultaneous loss of water and alkyl moieties from the m
