- Synthesis of Δ2-1,3-oxazolines and Δ2-1,3-oxazines using potassium fluoride on alumina
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Potassium fluoride (40%) on alumina was used as a basic reagent for the ring closure of N-(β- or γ-haloalkyl)amides to give Δ2-1,3-oxazolines and Δ2-1,3-oxazines, respectively. Various 2-alkyl and 2-aryl derivatives were synthesized in moderate to high yield under relatively mild conditions (KF/Al2O3, solvent, room temperature). The procedure also facilitated simple workup and purification of the products. New compounds synthesized by this method are: 5-bromomethyl-2-phenyl-Δ2-1,3-oxazoline, 4,4-dimethyl-2-vinyl-Δ2-1,3-oxazoline, and 5-methylene-2-phenyl-Δ2-1,3-oxazine. The last compound represents the first authentic example of a 5-functionally substituted oxazine without substitution in the 4- or the 6-position.
- Mitchell,Benicewicz
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- Ultrasound-Accelerated, Concise, and Highly Efficient Synthesis of 2-Oxazoline Derivatives Using Heterogenous Calcium Ferrite Nanoparticles and Their DFT Studies
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A rapid and operationally simple approach for synthesising biologically relevant 2-oxazoline derivatives has been developed through highly efficient ultrasound-promoted coupling reactions of thioamides and amino alcohols using calcium ferrite nanoparticles as heterogeneous catalysts. The major advantage of using ultrasound irradiation lies in the drastic reduction of reaction time as compared with conventional stirring. Furthermore, quantum chemical investigations for the synthesised 2-oxazoline derivatives have been carried out at the DFT/B3LYP/6-311 + G (d, p) level of theory to predict the optimized geometry. The molecular properties such as bond lengths, bond orders, Milliken charges, frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential map, and thermodynamic parameters of all the compounds have also been reported at the same level of theory.
- Atri, Shalu,Bendi, Anjaneyulu,Rao, G. B. Dharma,Raza, Mohd Jamshaiya,Sharma, Nutan
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- A mild and efficient synthesis of 2-oxazolines via transamidation- cyclodehydrosulfurisation of thioamides with 2-aminoethanol
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Transamidation of thioamides with 2-aminoethanol, followed by cyclodehydrosulfurisation of the resultant N-(β-hydroxyethyl)thioamides, has been utilised for the mild and efficient synthesis of 2-oxazolines. The developed protocol was found to be of general applicability. Georg Thieme Verlag KG Stuttgart · New York.
- Goud, D. Raghavender,Pathak, Uma
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supporting information
p. 3678 - 3682
(2013/02/22)
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- Synthesis of 2-oxazolines via boron esters of N-(2-hydroxyethyl) amides
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A new, convenient, one-pot process is presented for the synthesis of 2-oxazolines in high yields (75-94%) via boron esters of N-(2-hydroxyethyl) amides. The procedure involves thermolysis of the boron esters at 240-260 °C, in the presence of solid CaO as an acid scavenger and allows the preparation of oxazolines from hydroxyethyl amides of aliphatic and aromatic monocarboxylic acids.
- Ilkgul, Baris,Gunes, Deniz,Sirkecioglu, Okan,Bicak, Niyazi
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experimental part
p. 5313 - 5315
(2010/11/03)
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- Generation of cyclic ketene-N,X-acetals (X = O, S) from 2-alkyl-1,3-oxazolines and 2-alkyl-1,3-thiazolines. Reactions with acid chlorides, 1,3-diacid chlorides and N-(chlorocarbonyl) isocyanate
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2-Alkyl-1,3-oxazolines, 2-alkyl-1,3-thiazolines, and the corresponding cyclic ketene-N,X-acetals (X = O, S) derived from them were reacted with monoacid chlorides, diacid chlorides, triacid chlorides. A series of these carbon-carbon bond-forming reactions and cyclizations to both substituted 2,3-dihydrooxazolo[3,2-a]pyridine-5,7-diones and 2,3-dihydrothiazolo[3,2-a] pyridine-5,7-diones proceeded under mild reaction conditions. Cyclic ketene-N,X-acetal intermediates play important roles in all these reactions. Related cyclizations with N-(chlorocarbonyl) isocyanate formed substituted 2,3-dihydrooxazolo[3,2-c]pyrimidine-5,7-diones and 2,3-dihydrothiazolo[3,2-c] pyrimidine-5,7-diones. Georg Thieme Verlag Stuttgart.
- Zhou, Aihua,Pittman Jr., Charles U.
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- Lewis acid-catalyzed asymmetric diels-alder reactions using chiral sulfoxide ligands: chiral 2-(arylsulfinylmethyl)-1,3-oxazoline derivatives.
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New chiral sulfoxide-1,3-oxazoline ligands have been developed as chiral ligands for Lewis acid-catalyzed asymmetric Diels-Alder reactions. The use of chiral sulfinyl 1,3-oxazoline ligands in copper(II)-catalyzed asymmetric Diels-Alder reactions provided an endo cycloadduct as a major product with moderate enantioselectivity. A rationale is proposed for the mechanism of the asymmetric induction.
- Watanabe, Kazuhiro,Hirasawa, Takashi,Hiroi, Kunio
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p. 372 - 379
(2007/10/03)
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- Thiazole, imidazole and oxazole compounds and treatments of disorders associated with protein aging
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Provided are, among other things, compounds of formula I or IA, . Also provided are methods of treatment with such compounds.
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- Method for treating glaucoma IIB
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Provided is a method of decreasing intraocular pressure or improving ocular accommodation in an animal, including a human, comprising administering an intraocular pressure decreasing amount or ocular accommodation improving amount of a compound of the formula I or IA, wherein J is oxygen, sulfur, or N—Rd.
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- Synthesis of oxazolines and oxazines
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A process of preparing an oxazoline or oxazine compound of the formula STR1 wherein X is an atom selected from the group of oxygen and sulfur, R is selected from the group consisting of C1-10 alkyl, C1-10 fluoroalkyl, aryl and substituted-aryl, and n is 2 or 3 comprising ring-closing a compound of the formula STR2 wherein X is an atom selected from the group of oxygen and sulfur, R is selected from the group consisting of C1-10 alkyl, C1-10 fluoroalkyl, aryl, and substituted aryl, n is 2 or 3, and Y is a bromine or chlorine atom in the presence of a basic reagent consisting essentially of a fluoride salt supported on an inorganic solid substrate is disclosed together with the compounds, 5-bromomethyl-2-phenyl-1,3-oxazoline, 5-methylene-2-phenyl-1,3-oxazine and 4,4-dimethyl-2-vinyl-1,3-oxazoline.
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- Manufacture of 2-oxazolines, 2-oxazines, 2-imidazolines and 2-imidazines
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A process for the production of a product selected from the group consisting of a 2-oxazoline or a 2-oxazine and a 2-imidazoline or a 2-imidazine comprising reacting a bicyclic amide acetal with a member selected from the group consisting of an alkanol amine and an alkylene polyamine, respectively, at a temperature in the range of from about 20° C. to 200° C. is described.
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- SYNTHESIS OF ISOTHIOCYANATES FROM NON-AROMATIC NITROGEN-CONTAINING HETEROCYCLES
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Investigation of the reaction of thiophosgene with Δ2-oxazolines I, Δ3-thiazolines II, 4H-benzothiazines III, 2-methoxypentahydro-Δ1-azepine IV, theophylline and caffeine showed that only compounds I and IV reacted to give 2-acyloxyethyl isothiocyanates and methyl 6-isothiocyanatohexanoate.The structure of these products was corroborated by IR, 1H NMR, 13C NMR and mass spectral methods.The suitability of the above-mentioned compounds to react is discussed.
- Gonda, Jozef,Kristian, Pavol,Mikler, Lubomir
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p. 112 - 117
(2007/10/02)
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- A Novel Synthesis of 2-Substituted Oxazolines
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Thermal rearrangement of N-acyl-2-oxazolidones in the presence of calcium oxide has been shown to provide a new entry into 2-substituted oxazolines.
- Mundy, Bradford P.,Kim, Youseung
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p. 1221 - 1222
(2007/10/02)
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- A Convenient Laboratory Synthesis of 2-Oxazoline (1)
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The reaction of 2-chloroethylformamide (1a) with sodium hydride, in N-methyl-2-pyrrolidone, at reduced pressure, gave anhydrous 2-oxazoline (2a) in good yield.
- Franco, Fidencio,Muchowski, Joseph M.
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