- Enantioselective Synthesis of Functionalized Diazaspirocycles from 4-Benzylideneisoxazol-5(4H)-one Derivatives and Isocyanoacetate Esters
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Enantioenriched spirocyclic compounds bearing three contiguous stereocenters and high functionalization were obtained through a formal [3+2] cycloaddition reaction catalyzed by a cooperative system. The spiro compounds were synthesized from 4-arylideneisoxazol-5-ones and isocyanoacetate esters using a bifunctional squaramide/Br?nsted base organocatalyst derived from a Cinchona alkaloid and silver oxide as Lewis acid. This method afforded two out of the four possible diastereomers with good yields and high enantiomeric excess for both diastereomers. (Figure presented.).
- Martínez-Pardo, Pablo,Laviós, Adrián,Sanz-Marco, Amparo,Vila, Carlos,Pedro, José R.,Blay, Gonzalo
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- Palladium catalyzed insertion reaction of isocyanides with 3-arylisoxazol-5(4 H)-ones: Synthesis of 4-aminomethylidene isoxazolone derivates
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A palladium catalyzed insert reaction of isocyanides to 3-arylisoxazol-5(4H)-ones for the construction of 4-aminomethylidene isoxazolone derivates is reported. In this transformation, only the C-H bond of the methylene group was involved while the remaining ring structure was retained. In general, this work provided a new protocol for the synthesis of 4-aminomethylidene isoxazolones.
- Zhu, Yi-Ming,Xu, Pei,Wang, Shun-Yi,Ji, Shun-Jun
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- Potassium fluoride on alumina: Dry condensation of 3-phenylisoxazol-5-one with aldehydes under microwave irradiation
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3-Phenylisoxazol-5-one (2) and aromatic aldehydes were condensed to 3-phenyl-(4-arylmethylene) isoxazol-5-one (3) in the presence of Al203-KF without solvent under microwave irradiation.
- Villemin,Martin,Garrigues
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- Organocatalytic Enantioselective 1,6-aza-Michael Addition of Isoxazolin-5-ones to p-Quinone Methides
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A thiourea-Br?nsted base bifunctional catalyst allowed the enantioselective 1,6-aza-Michael addition of isoxazolin-5-ones to p-quinone methides to give isoxazolin-5-ones having a chiral diarylmethyl moiety attached to the N atom with fair to good yields and enantiomeric excesses. To the best of our knowledge this reaction represents the first example of enantioselective N-alkylation of isoxazolin-5-ones as well as the first example of enantioselective 1,6-aza-Michael reaction involving p-quinone methides.
- Torán, Ricardo,Vila, Carlos,Sanz-Marco, Amparo,Mu?oz, M. Carmen,Pedro, José R.,Blay, Gonzalo
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- Stereoselective Michael Halogenation Initiated Ring Closure (MHIRC) Synthesis of Spirocyclopropanes from Benzylidenemalononitriles and 3-Arylisoxazol-5(4H)-ones
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The new chemical cascade reaction was found: the direct formation of substituted 4-oxo-2,7-diaryl-5-oxa-6-azaspiro[2.4]hept-6-ene-1,1-dicarbonitriles from benzylidenemalononitriles and 3-aryl-2-isoxazol-5(4H)-ones. The action of bromine on the equimolar mixture of benzylidenemalononitrile and 3-aryl-2-isoxazol-5(4H)-one in the basic alcohol solution results in stereoselective formation of spirobicycle containing the 2-isoxazolin-5-one and the cyclopropane fragments in 53-92% yields. Thus, the new simple and efficient ‘one-pot’ approach to substituted (2R*,3R*)-4-oxo-2,7-diaryl-5-oxa-6-azaspiro[2.4]hept-6-ene-1,1-dicarbonitriles was found directly from simple and reasonable starting compounds as benzylidenemalonitriles and 3-aryl-2-isoxazol-5(4H)-ones.
- Vereshchagin, Anatoly N.,Elinson, Michail N.,Korshunov, Alexander D.,Anisina, Yuliya E.,Novikov, Roman A.,Goloveshkin, Alexander S.,Bushmarinov, Ivan S.,Zlotin, Sergey G.,Egorov, Mikhail P.
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- The tyrosinase inhibitory effects of isoxazolone derivatives with a (Z)-β-phenyl-α, β-unsaturated carbonyl scaffold
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Thirteen (Z)-4-(substituted benzylidene)-3-phenylisoxazol-5(4H)-ones were designed to confirm the geometric effect of the double bond of the β-phenyl-α, β-unsaturated carbonyl scaffold on tyrosinase inhibitory activity. Compounds 1a–1m, which all possessed the (Z)-β-phenyl-α, β-unsaturated carbonyl scaffold, were synthesized using a tandem reaction consisting of an isoxazolone ring formation and a Knoevenagel condensation, and three starting materials, ethyl benzoylacetate, hydroxylamine and benzaldehydes. Some of the compounds showed inhibitory activity against mushroom tyrosinase as potent as compounds containing the “(E)”-β-phenyl-α, β-unsaturated carbonyl scaffold. Compounds 1c and 1m showed greater inhibitory activity than kojic acid: IC50 = 32.08 ± 2.25 μM for 1c; IC50 = 14.62 ± 1.38 μM for 1m; and IC50 = 37.86 ± 2.21 μM for kojic acid. A kinetic study indicated that 1m inhibited tyrosinase in a competitive manner and that it probably binds to the enzyme's active site. In silico docking simulation supported binding of 1m (?7.6 kcal/mol) to the active site of tyrosinase with stronger affinity than kojic acid (?5.7 kcal/mol). Similar results were obtained using cell-based assays, and in B16F10 cells, compound 1m dose-dependently inhibited tyrosinase activity and melanogenesis. These results indicate the anti-melanogenic effect of compound 1m is due to the inhibition of tyrosinase and (Z)-isomer of the β-phenyl-α, β-unsaturated carbonyl scaffold can, like its congener the (E)-isomer, act as an excellent scaffold for tyrosinase inhibition.
- Kim, Su Jeong,Yang, Jungho,Lee, Sanggwon,Park, Chaeun,Kang, Dongwan,Akter, Jinia,Ullah, Sultan,Kim, Yeon-Jeong,Chun, Pusoon,Moon, Hyung Ryong
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- A synthetic route towards 3,4-disubstituted pyrrolidin-2-ones: via a Michael addition and reductive ring closing strategy
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Pyrrolidin-2-one derivatives were synthesized via DABCO mediated Michael addition of isoxazol-5(4H)-ones with nitroalkenes, followed by one pot reduction of the nitro group and ring cleavage with cyclization. 2-Pyrrolidinone scaffolds with a wide range of substituents were synthesized with good yield and diastereoselectivity by using this protocol.
- Dawange, Monali,Parekh, Nikita,Kumbhar, Avinash,Dehaen, Wim,Kusurkar, Radhika
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- Construction of isoxazolone-fused phenanthridinesviaRh-catalyzed cascade C-H activation/cyclization of 3-arylisoxazolones with cyclic 2-diazo-1,3-diketones
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A Rh(iii)-catalyzed cascade C-H activation/intramolecular cyclization of 3-aryl-5-isoxazolones with cyclic 2-diazo-1,3-diketones was described, leading to the formation of isoxazolo[2,3-f]phenanthridine skeletons. The protocol features the simultaneous one-pot formation of two new C-C/C-N bonds and one heterocycle in moderate-to-good yields with good functional group compatibility. It is amenable to large-scale synthesis and further transformation.
- Hu, Wangcheng,He, Xinwei,Zhou, Tongtong,Zuo, Youpeng,Zhang, Shiwen,Yang, Tingting,Shang, Yongjia
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supporting information
p. 552 - 556
(2021/02/06)
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- Suzuki-Miyaura cross-coupling of 3,4-disubstituted 5-bromoisoxazoles: An efficient access to trisubstituted isoxazoles
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The Suzuki-Miyaura cross-coupling of 3,4-disubstituted 5-bromoisoxazoles 1 at the C5 position has successfully proceeded in the presence of Pd2(dba)3 and P(t-Bu)3·HBF4 catalysts to give the corresponding trisubstituted isoxazoles 3 in good to high yields while suppressing the formation of ketone 4 as a byproduct. The use of bulky phosphine ligand P(t-Bu)3·HBF4 is essential for the current transformation, and the formation of ketone 4, which was a major product in the previous report, was able to be suppressed under the current conditions.
- Morita, Taiki,Nakamura, Hiroyuki,Tsuda, Masato
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supporting information
(2021/06/07)
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- Palladium Catalyzed Ring Expansion Reaction of Isoxazolones with Isocyanides: Synthesis of 1,3-Oxazin-6-One Derivatives
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A palladium catalyzed ring expansion reaction of isoxazolones with isocyanides was disclosed. In the reaction, a cascade process involving ring-opening/cyclization was suggested. The reaction features high atomic economy due to no elimination of CO2 occurred. Moreover, products obtained demonstrate aggregation-induced emission properties with relatively high solid-state emission efficiencies. (Figure presented.).
- Zhu, Yi-Ming,Zhang, Wan,Li, Hongkun,Xu, Xiao-Ping,Ji, Shun-Jun
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p. 808 - 818
(2020/12/03)
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- NH2OH-HCl-Mediated Umpolung α-Methylsulfonylation of α-Sulfonyl Ketones with Methylsulfoxides: Synthesis of α,β-Bis-sulfonyl Arylketones
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In this paper, a novel and efficient route for the synthesis of α,β-bis-sulfonyl arylketones via an NH2OH-HCl-mediated intermolecular umpolung α-methylsulfonylation of α-sulfonyl ketones with methylsulfoxides is described. A plausible mechanism is proposed and discussed. Various reaction conditions for this efficient, one-pot, environmentally friendly transformation were investigated.
- Chang, Meng-Yang,Chen, Han-Yu,Tsai, Yu-Lin
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supporting information
p. 1832 - 1836
(2019/03/07)
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- Quantum chemical-guided steglich rearrangement of azlactones and isoxazolones
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The theoretical-guided evaluation of the Steglich rearrangement of azlactones and isoxazolones allowed the determination of the reactivity patterns in these heterocycles, including the factors that drive the regioselectivity toward both possible sites. These results allowed the first experimental report on the regioselective Steglich rearrangement of isoxazolones, affording the nitrogen- or carbon-acyloxy adducts.
- De Castro, Pedro P.,Dos Santos, Juliana A.,De Siqueira, Marcelo M.,Batista, Gabriel M. F.,Dos Santos, Hélio F.,Amarante, Giovanni W.
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p. 12573 - 12582
(2019/10/11)
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- 2-Bromo-4-chlorofuran[2,3-b]quinoline, derivatives thereof, their synthetic methods and application
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The invention discloses a full-synthetic method of 2-bromo-4-chlorofuran[2,3-b]quinoline, derivatives of 2-bromo-4-chlorofuran[2,3-b]quinoline, and synthetic method and application of the derivatives.The preparation methods applied herein have mild reaction conditions; reagents used herein are low in toxicity; the raw materials are low in price and easy to attain; after-treatment is convenient; massive enrichment is available. Pharmacological experiments show that most of the compounds herein have good antitumor activity and high stability and are expectedly developable into antitumor drugs.
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Paragraph 0028-0032
(2019/08/07)
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- Visible Light-Promoted Beckmann Rearrangements: Separating Sequential Photochemical and Thermal Phenomena in a Continuous Flow Reactor
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The Beckmann rearrangement of oximes to amides typically requires strong acids or highly reactive, hazardous electrophiles and/or elevated temperatures to proceed. A very attractive alternative is the in situ generation of Vilsmeier–Haack reagents, by means of photoredox catalysis, as promoters for the thermal Beckmann rearrangement. Investigation of the reaction parameters for this light-induced method using a one-pot strategy has shown that the reaction is limited by the different temperatures required for each of the two sequential steps. Using a continuous flow reactor, the photochemical and thermal processes have been separated by integrating a flow photoreactor unit at low temperature for the electrophile generation with a second reactor unit, at high temperature, where the rearrangement takes place. This strategy has enabled excellent conversions and yields for a diverse set of oximes, minimizing the formation of side products obtained with the original one-pot method.
- Chen, Yuesu,Cantillo, David,Kappe, C. Oliver
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supporting information
p. 2163 - 2171
(2019/03/14)
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- Cooperative Catalysis with Coupled Chiral Induction in 1,3-Dipolar Cycloadditions of Azomethine Ylides
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1,3-Dipolar cycloadditions (1,3-DC) between imino esters (as precursors of N-metallated azomethine ylides) and π-deficient alkenes are promoted by cooperative asymmetric Lewis acid/Br?nsted base catalysis. The components of these catalytic pairs are silver salts derived from enantiopure commercially available BINOL-based phosphoric acids and Cinchona alkaloids. Chiral phosphoric silver(I) salts promote HOMO raising of in situ formed 1,3-dipoles, whereas protonated cinchona alkaloids generate a LUMO lowering for the dipolarophiles resulting in a global acceleration of the 1,3-DC. The best results were obtained with BINOL-derived silver phosphate and hydrocinchonine. Matching between both cooperative metallo- and organocatalyst results in an enhanced enantiomeric excess, superior to that reached by both separate components. NOESY experiments and DFT calculations are compatible with a non-covalent interaction (hydrogen bond) between both catalysts, which results in close contacts and mutually coupled chiral environments.
- Cayuelas, Alberto,Larra?aga, Olatz,Selva, Verónica,Nájera, Carmen,Akiyama, Takahiko,Sansano, José M.,de Cózar, Abel,Miranda, José I.,Cossío, Fernando P.
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supporting information
p. 8092 - 8097
(2018/05/30)
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- Atom-Economic Silver-Catalyzed Difunctionalization of the Isocyano Group with Cyclic Oximes: Towards Pyrimidinediones
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An unprecedented silver-catalyzed difunctionalization of the isocyano group with cyclic oximes is described. This method allows efficient and atom-economic assembly of a vast array of structurally novel and interesting pyrimidinediones, and tolerates a range of functionalities. The resulting products can be easily converted into some useful compounds. Furthermore, the method can also be applied for the late-stage modification of a few biologically active molecules.
- Liang, Hong-Wen,Yang, Zhen,Jiang, Kun,Ye, Ying,Wei, Ye
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supporting information
p. 5720 - 5724
(2018/04/25)
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- An Aminocatalyzed Stereoselective Strategy for the Formal α-Propargylation of Ketones
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A two-step reaction sequence is described for the asymmetric formal α-propargylation of ketones. This approach takes advantage of an aminocatalyzed conjugate addition of ketones to alkylidene isoxazol-5-ones, followed by a controlled nitrosative degradation event. The target compounds can be accessed in broad scope, in moderate to good yields, perfect diastereocontrol and good to excellent enantioselectivity.
- Jurberg, Igor D.
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supporting information
p. 9716 - 9720
(2017/07/25)
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- One-pot Synthesis of 3-phenyl-4-pyrazolylmethylene-isoxazol-(5H)-ones Catalyzed by Sodium Benzoate in Aqueous Media under the Influence of Ultrasound Waves: A Green Chemistry Approach
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A series of 4-pyrazolylmethylene-3-phenylisoxazol-5(4H)-ones have been prepared from Knoevenagel condensation of pyrazole-4-carbaxaldehyde with isoxazolone precursors or via one-pot three-component cyclocondensation of pyrazole-4-carbaxaldehyde with β-ketoesters and hydroxylamine hydrochloride in the presence of sodium benzoate in water under the influence of ultrasonic waves. The merits of this method are efficient, clean, green, easy work-up, high yields, and shorter reaction time, and the catalyst could be recycled easily without affecting the catalytic activity.
- Konkala, Veera Swamy,Dubey, Pramod Kumar
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p. 2483 - 2492
(2017/07/25)
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- A 3 - substituted - 4 - isoxazole carboxylic acid synthesizing method
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The invention relates to a synthesis method of high-purity and high-regioselectivity 3-substituted-4-isoxazole carboxylic acid. The method has the advantages of simplicity and easiness in operation, mild reaction and high yield and can solve the technical problems of harsh reaction conditions, generation of isomers, difficulty in separation, low total yield and difficulty in large-scale production of the existing preparation method. The preparation steps are as follows: taking 3-substituted-3-oxopropionate (I) as a starting raw material, and performing cyclization with hydroxylamine hydrochloride and an alkali in water to prepare 3-substituted-4-isoxazole-5-ketone (II); performing acetalization on the compound (II) and N, N-dimethylformamide dimethyl acetal to prepare 4-dimethylaminomethylene-3-substituted-4-hydrogen-isoxazol-5-ketone (III); performing ring opening by hydrolysis of lactone on the compound (III) in alkaline conditions and re-closing a ring; and acidifying to obtain the 3-substituted-4-isoxazole carboxylic acid. The method for the 3-substituted-4-isoxazole carboxylic acid, provided by the invention, is used for development and large-scale preparation.
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Paragraph 0046-0049
(2017/08/23)
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- Michael Addition of Soft Carbon Nucleophiles to Alkylidene Isoxazol-5-ones: A Divergent Entry to β-Branched Carbonyl Compounds
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A novel, divergent strategy toward the synthesis of β-branched (and linear) carbonyl compounds is developed by taking advantage of alkylidene isoxazol-5-ones as key building blocks. The yields obtained range from good to excellent, therefore making the described methods attractive options for building such molecules. (Chemical Equation).
- Capreti, Naylil M. R.,Jurberg, Igor D.
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supporting information
p. 2490 - 2493
(2015/05/27)
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- Regioselective catalytic asymmetric C-alkylation of isoxazolinones by a base-free palladacycle-catalyzed direct 1,4-addition
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Isoxazolinones constitute a class of heterocycles utilized for the development of novel drug candidates. The cyclic oxime ester motif is also synthetically useful as it contains functional handles which have previously been used to provide access to an assortment of valuable compound classes not easily accessible by alternative approaches. However, asymmetric methods towards isoxazolinones are notoriously scarce. Herein we report the first catalytic asymmetric alkylations of isoxazolinones forming all-C-substituted quaternary stereocenters. The present studies were driven by the question of how to control the regioselectivity in the competition of different nucleophilic positions. The investigation of a direct 1,4-addition uncovered that a sterically demanding palladacycle catalyst directs the reactivity in the absence of a base nearly exclusively to the nucleophilic C atom, while at the same time it allows for high enantioselectivity and TONs up to 1900.
- Hellmuth, Tina,Frey, Wolfgang,Peters, Ren
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supporting information
p. 2788 - 2791
(2015/03/04)
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- Synthesis and herbicidal activity of novel 4-acyl-2,5-disubstituted-3- hydroxypyrazoles and 4-arylcarbonyl-3-substitutedisoxazol-5-ones
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Two series of novel 4-acyl-2,5-disubstituted-3-hydroxypyrazoles 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h and 4-arylcarbonyl-3-substitutedisoxazol-5-ones 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i were synthesized by the Scotton-Baumann reaction of 2,5-disubstituted-2,4-dihydro-pyrazol-3-ones 1 or 3-substituted-4H-isoxazol-5- ones 6 and various acyl chlorides, followed by the Fries rearrangement in the presence of calcium hydroxide and calcium oxide as the catalyst. Their structures were confirmed by IR, 1H NMR, mass spectroscopy, and elemental analyses. 1H NMR indicated that compounds 3 existed in enol forms and compounds 7 in keto configurations. The results of preliminary bioassays showed that some of the title compounds 3 and 7 exhibited moderate to good herbicidal activities against Brassica campestris L. at the concentration of 100 mg/L. Isoxazole compounds 7 showed better herbicidal activity against B. campestris L. than pyrazole compounds 3 did at the concentration of 100 mg/L. Moreover, most of the isoxazole compounds displayed higher herbicidal activity against B. campestris L. than Echinochloa crus-galli. However, these compounds showed weak herbicidal activities at the concentration of 10 mg/L.
- Song, Hong,Feng, Wei-Bing,Cheng, Feng,Shi, De-Qing
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p. 1381 - 1385
(2014/01/06)
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- Fast and efficient synthesis of 4-arylidene-3-phenylisoxazol-5-ones
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A convenient and easy synthesis of 4-arylidene-3-phenylisoxazol-5-ones by the three-component reaction of hydroxylamine, ethyl benzoylacetate and aromatic aldehydes in the presence of DABCO in refluxing ethanol is reported.
- Mirzazadeh, Maryam,Mahdavinia, Gholam Hossein
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experimental part
p. 425 - 429
(2012/05/20)
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- Synthesis of novel isoxazole fused heterocycles
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Condensation of 3-aryl-4-formyl isoxazoles with 1,2-diamines led to the formation of 3-aryl-(6,7-benzo-1,5-heptadiazino)(3,2-d)-isoxazoles or isoxazolo-[5,4-b]-benzodiazepines and 3,10-diaryl-6,7,14,15-tetrhydro-13 H,16H-diisoxazole-(4,5-b;4,5-l)(1,4,8,11)-tetra-aza-cyclo-tetra-deca-4, 14-diones, the novel seven-and 14-membered heterocyclic systems. Similar compounds are of great importance in medicinal chemistry.
- Rajender, P. Sarita,Sridevi,Reddy, K. Kondal
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experimental part
p. 2191 - 2200
(2012/06/16)
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- Photocycloaddition of aromatic and aliphatic aldehydes to isoxazoles: Cycloaddition reactivity and stability studies
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The first photocycloadditions of aromatic and aliphatic aldehydes to methylated isoxazoles are reported. The reactions lead solely to the exo-adducts with high regio- and diastereoselectivities. Ring methylation of the isoxazole substrates is crucial for high conversions and product stability. The 6-arylated bicyclic oxetanes 9a-9c were characterized by X-ray structure analyses and showed the highest thermal stabilities. All oxetanes formed from isoxazoles were highly acid-sensitive and also thermally unstable. Cleavage to the original substrates is dominant and the isoxazole derived oxetanes show type T photochromism.
- Griesbeck, Axel G.,Franke, Marco,Neudoerfl, Joerg,Kotaka, Hidehiro
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experimental part
p. 127 - 134
(2011/05/16)
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- Rhodium(III)-catalyzed synthesis of isoquinolines from aryl ketone o -acyloxime derivatives and internal alkynes
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A synthetic method of isoquinolines from aryl ketone O-acyloxime derivatives and internal alkynes has been developed using [Cp*RhCl 2]2 - NaOAc as the potential catalyst system. The present transformation is carried out by a redox-neutral sequence of C - H vinylation via ortho-rhodation and C - N bond formation of the putative vinyl rhodium intermediate on the oxime nitrogen, where the N - O bond of oxime derivatives could work as an internal oxidant to maintain the catalytic cycle.
- Too, Pei Chui,Wang, Yi-Feng,Chiba, Shunsuke
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supporting information; experimental part
p. 5688 - 5691
(2011/03/23)
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- Heteropolyacids as green and reusable catalysts for the synthesis of isoxazole derivatives
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Heteropolyanions with different structures, including Keggin, Dawson, Preyssler, mixed addenda, and sandwich types, catalyzed the formation of 1,3-diphenyl-isoxazole from the condensation of 1,3-diphenyl-propane-1,3-dione and hydroxylamine hydrochloride in different solvents and under heating conditions. Our data vividly indicate that H3PW11CuO40 is the catalyst of choice and could catalyze the synthesis of other isoxazole derivatives in high yields and good selectivities. Copyright Taylor & Francis Group, LLC.
- Heravi, Majid M.,Derikvand, Fatemeh,Haeri, Anahita,Oskooie, Hossein A.,Bamoharram, Fatemeh F.
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p. 135 - 140
(2008/03/14)
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- Efficient regioselective synthesis of 4- and 5-substituted isoxazoles under thermal and microwave conditions
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(Chemical Equation Presented) The [2+3] cycloaddition reaction between nitrile oxides 2 and the captodative olefins 1 or the methyl crotonate derivatives 4 is regioselective and leads to the formation of the 5-substituted amino-isoxazole 3 or the 4-substi
- Lasri, Jamal,Mukhopadhyay, Suman,Charmier, M. Adilia Januario
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scheme or table
p. 1385 - 1389
(2009/04/10)
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- New synthetic methods: Part I - Regioselective 1, 2-transposition of carbonyl group in carbocyclic and heterocyclic ketones
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A convenient and simple synthetic method for 1, 2- transposition of keto group in pyrazol-5-ones, indan-1,3-dione and benzofuran-3-one is described.
- Chande, Madhukar S.,Amle, Anand P.
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p. 2625 - 2627
(2007/10/03)
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- Reactivity of p-phenyl substituted β-enamino compounds using k- 10/ultrasound. II [1]. Synthesis of isoxazoles and 5-isoxazolones
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The condensation of 4-phenyl substituted β-enamino ketones 1a-d and β- enamino esters 5a-d with hydroxylamine hydrochloride using K-10 as the solid support under sonication was studied to evaluate the formation of isoxazole and 5-isoxazolone rings from β-enamino compounds with a substituted aromatic ring. Isoxazoles 2a-c, 3c-d and 5-isoxazolones 6a-c and 7a-d were obtained. The use of K-10/ultrasound in this reaction furnished novel results in some cases.
- Valduga, Claudete J.,Santis, Denise B.,Braibante, Hugo S.,Braibante, Mara E. F.
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p. 505 - 508
(2007/10/03)
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- Synthesis of 1H-1,5-benzodiazepin-2(3H)-ones from 5(4H)-isoxazolone, a heterocyclic bifunctional C-3 synthon
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Unsubstituted and 7- or 8-substituted 4-aryl-1H-1,5-benzodiazepin-2(3H)-ones 3a-t have been synthesized by the condensation of 3-aryl-5(4H)-isoxazolones 1a-e and parent 4-substituted 1,2-benzenediamines 2a-d under acidic conditions.
- Rao,Reddy,Veeranagaiah
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p. 446 - 448
(2007/10/02)
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- Action de l'hydroxylamine sur les dihydro-1,3 benzodiazepine-1,5 thiones (ones)-2
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The reaction of hydroxylamine with 4-phenyl-1,5-benzodiazepin 2-thiones(ones) 1-6 has been investigated.Depending upon the starting benzodiazepine either the 3-phenyl-5-N-(2-amino phenyl)amino isoxazoles 8, 10, 11 3-N-(2-aminophenylimino) 3-phenyl propionohydroxamic acid or 3-phenyl 5-isoxazolone 14 was obtained.The structure of compounds 8, 10, 11 have been unambiguously established by catalytic hydrogenation.A mechanism for this transposition has been suggested.
- Essassi, El Mokhtar,Salem, Moussa,Viallefont, Philippe
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p. 890 - 892
(2007/10/02)
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