共查询到20条相似文献,搜索用时 31 毫秒
1.
Masakazu Kogami 《合成通讯》2013,43(5):681-688
Lithium chloride was found to accelerate formation of the Grignard reagent from inactive 3-bromo-2-methylthiophene (1) and commercial magnesium metal. Based on this finding, a convenient and potentially scalable preparation of ethyl 2-methylthiophene-3-carboxylate (3) was achieved. In addition, this process has been found to provide a new, general approach to 3-substituted 2-methylthiophenes. 相似文献
2.
Ikuko Ueda 《Tetrahedron letters》2006,47(48):8535-8537
Reaction of 2,3-dibromo-1-methylindole with tert-butyllithium at −78 °C followed by treatment with tropylium ion gave 2-bromo-3-cycloheptatrienyl-1-methylindole in a moderate yield, indicating that 2-bromo-3-lithio-1-methylindole would be involved as an intermediate instead of 3-bromo-2-lithio-1-methylindole. The structure of 2-bromo-3-cycloheptatrienyl-1-methylindole was unequivocally determined by a single X-ray analysis. 2,3-Diiodo-1-methylindole also gave a 3-lithio derivative exclusively. 相似文献
3.
V. I. Pavlovsky S. Yu. Bachinskii N. A. Tkachuk S. Yu. Makan S. A. Andronati Yu. A. Simonov I. G. Filippova M. Gdaniec 《Chemistry of Heterocyclic Compounds》2007,43(8):1029-1037
The condensation of 5-aryl-7-bromo-1,2-dihydro-3H-1,4-benzodiazepin-2-ones with aromatic aldehydes gives 5-aryl-3-arylidene-and
5-aryl-7-bromo-3-hetarylidene-1,2-dihydro-3H-1,4-benzodiazepin-2-ones. X-ray diffraction structural analysis yielded the molecular
and crystal structures of 7-bromo-3-(4′-methoxybenzylidene)-5-phenyl-1,2-dihydro-3H-1,4-diazepin-2-one and showed that this
compound has cis configuration. Radioligand analysis was used to study the affinity of these products toward central nervous
system and peripheral benzodiazepine receptors.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1213–1225, August, 2007. 相似文献
4.
Hiroyuki Shinohara Motohiro Sonoda Naoya Hayagane Shota Kita Shinji Tanimori Akiya Ogawa 《Tetrahedron letters》2014
A convenient silica gel-promoted synthesis of 2-bromo-3-hydroxybenzoate derivatives has been developed via the Diels–Alder reaction of furans with methyl 3-bromopropiolate, followed by a ring-opening aromatization. In addition, 2-bromo-3-methoxybenzoate, derived from 2-bromo-3-hydroxybenzoate with iodomethane, was found to be a good substrate for Pd-catalyzed cross-coupling reactions, despite its sterically hindered structure. 相似文献
5.
Yu. N. Polivin R. A. Karakhanov S. V. Makarshin B. I. Vgrak V. I. Kelarev 《Russian Chemical Bulletin》1993,42(6):1106-1107
3-Bromo-2-ethyltetrahydropyran undergoes isomerization at 230 °C into a 6411 mixture of 7-bromo-4-heptanone and 7-bromo-3-heptanone.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1147–1149, June, 1993. 相似文献
6.
Yu. N. Polivin B. I. Ugrak T. S. Sheveleva R. A. Karakhanov 《Russian Chemical Bulletin》1992,41(6):1120-1123
The reaction ofRS(SR)-2,3-dibromo- and 2,3-dichlorotetrahydrofurans with ethylmagnesium bromide in ether was investigated. It was shown that the main reaction products are 2-ethyl-3-bromotetrahydrofuran (27%) and 3-bromo-2-(2-ethyl-3-tetrahydrofuryl)tetrahydrofuran (65%) in the first case and 2-ethyl-3-chlorotetrahydrofuran (33%) and 3-chloro-2-(3-chloro-2-tetrahydrofuryl)tetrahydrofuran (65%) in the second.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. I. M. Gubkin Moscow Institute of Petroleum and Gas, 111917 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1430–1434, June, 1992. 相似文献
7.
Valerij Ch. Christov Ivaylo K. Ivanov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2445-2454
A method for the synthesis of the 3-methyl-1,2,4-pentatrienyl phenyl sulfoxide 3 by [2,3]-sigmatropic rearrangement of the 3-methyl-1-penten-4-yn-3-yl benzenesulfenate 2 , formed in the reaction of the 3-methyl-1-pentene-4-yn-2-ol 1 with phenylsulfenyl chloride has been created. Possibilities and restrictions of the five-membered heterocyclization in electrophile-induced reactions leading to the synthesis of the 5H-1,2-oxathiol-2-ium salts 5 , 7 , and 8 have been explored. Chlorination of the sulfoxide 2 proceeded with formation of the (E)-2-chloro-3-methylene-1,4-pentadienyl phenyl sulfoxide 4 , while the bromination afforded the 4-bromo-5H-1,2-oxathiol-2-ium bromide 5 , which after reflux in 1,2-dichloroethane eliminated hydrogen bromide and was transformed into the (E)-2-bromo-3-methylene-1,4-pentadienyl phenyl sulfoxide 6 . 相似文献
8.
E. A. Dikusar V. I. Potkin N. G. Kozlov S. K. Petkevich N. V. Kovganko 《Chemistry of Natural Compounds》2006,42(3):254-258
Previously undescribed 2-bromo-3,4,4-trichlorobut-3-enoates 1b-23b were synthesized in 84–91% yield from natural alcohols including terpenes and steroids, plant phenols, and oximes of natural
carbonyl compounds 1a-23a by reaction of 2-bromo-3,4,4-trichlorobut-3-enoyl chloride in the presence of pyridine.
__________
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 212–215, May–June, 2006. 相似文献
9.
Willem A.L. van Otterlo 《Tetrahedron letters》2004,45(26):5091-5094
Contrary to literature reports, bromination of 3-hydroxybenzaldehyde can afford both 2-bromo-5-hydroxybenzaldehyde and 2-bromo-3-hydroxybenzaldehyde, but 4-bromo-3-hydroxybenzaldehyde was not detected. 2-Bromo-3-hydroxybenzaldehyde was converted into 2-(benzyloxy)-1-bromo-5-methoxy-7-methylnaphthalene. X-ray crystallographic analysis supports the identity of 2-bromo-3-hydroxybenzaldehyde. 相似文献
10.
11.
Alemayehu Mekonnen Andreas Westerlund Martina Havelkova Alexandre Descomps 《合成通讯》2013,43(14):2472-2480
Synthetic procedures for the preparation of 1-bromo-3-butyn-2-one and 1,3-dibromo-3-buten-2-one are given. These compounds are prepared from 2-bromomethyl-2-vinyl-1,3-dioxolane, which can readily be prepared from 2-ethyl- 2-methyl-1,3-dioxolane. The synthetic routes are as follows: 2-bromomethyl-2-vinyl-1,3-dioxolane is converted to 2-(1,2-dibromoethyl)-2-bromomethyl-1,3-dioxolane. Double dehydrobromination with tBuOK affords 2-ethynyl-2-bromomethyl-1,3-dioxolane. Formolysis with formic acid gives 1-bromo-3-butyn-2-one. Deacetalized 2-bromoethyl-2-vinyl-1,3-dioxolane was treated with Br2 and Li2CO3/12-crown-4 in tetrahydrofuran to give 1,3-dibrom-3-buten-2-one in moderate yield. 相似文献
12.
An easy and efficient method for the synthesis of multisubstituted cyclopropane derivatives from electron-deficicent alkenes with 2-bromo-1,3-propanedione compounds was described. For this method, ethyl α-cyanocinnamate derivatives 1 and β,β-dicyanostyrene derivatives 4 can all smoothly react with 2-bromo-1,3-propanedione compounds 2 to afford the corresponding multisubstituted cyclopropane derivatives 3 and 5 in good to excellent yields(up to 100%) promoted by anhydrous K3PO4 in DMF at room temperature, respectively. A possible mechanism of this reaction was proposed. Structures of all the products were confirmed by 1H NMR, 13C NMR and HRMS. 相似文献
13.
A simple method for microwave-assisted amination of 3-bromo-2-chloropyridine with various substituted aminoethanols is described. The reaction was carried out under microwave irradiation conditions (at 180 °C for 1-2 h) and the result was superior in terms of conversion and yield when compared to that of the corresponding conventional heating conditions. 相似文献
14.
以(S)-2-氨基丙醇和氯乙酰氯为起始原料,经酰化和环合反应制得(S)-5-甲基吗啉-3-酮(4); 4经还原制得(S)-3-甲基吗啉(5); 5与4-溴-2-甲基苯甲酸酰化缩合合成了(S)-(4-溴2-甲基苯基)(3-甲基吗啉)-甲酮,总收率57%,其结构经1H NMR 和 13C NMR确证。 相似文献
15.
以2-溴代-3-甲基环己酮和2-溴代-5-甲基环己酮混合物及2-甲基苯硫酚为原料,经耦合、环化及纯化制得1,2,3,4-四氢-2,6-二甲基二苯并噻吩(3);3在三氟乙酸中经锌粉还原合成了1,2,3,4,4a,9b-六氢-2,6-二甲基二苯并噻吩(4).3和4的结构经1H NMR,13C NMR和GC-MS确证. 相似文献
16.
Reaction of zirconacyclopentadienes with 2-bromoalkenes in the presence of CuCl afforded multisubstituted benzene derivatives. The reactions of 2-bromoacrylate and 2-bromo-3-phenylacrylaldehyde afforded penta- and hexasubstituted benzenes in good yields. The reaction of 3-bromofuran-2,5-dione with zirconacyclopentadienes gave isobenzofuran-1,3-diones in good yields. 相似文献
17.
B. V. Ashalatha B. Narayana K. K. Vijaya Raj 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1904-1919
Novel chalcones 1-(3-bromothien-2-yl)-3-(aryl)prop-2-en-1-ones derived from 3-bromo-2-acetylthiophene and their cyclization product with ethylacetoacetate such as 4-(3-bromothien-2-yl)-2-oxo-6-(aryl)cyclohex-3-ene-1-carboxylate derivatives were synthesized and studied by X-ray, analytical, and spectral methods. Compounds were screened for their anti-inflammatory, analgesic, and antimicrobial activities. The compound ethyl-4-(3-bromothien-2-yl)-2-oxo-6-(4-propoxyphenyl) cyclohex-3-ene-1-carboxylate 5c exhibited promising anti-inflammatory, analgesic and antibacterial activities. 相似文献
18.
Fawzy A. Attaby Sanaa M. Eldin Mohamed A. A. Elneairy Ali K. K. El-Louh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2205-2220
Cyanothioacetamide (f 1) reacted with α,β -unsaturated carbonyl compounds 2a–d to afford thioxohydropyridine-3-carbonitriles 5a–d, which were used as the starting materials for the preparation of several thienopyridines via their reactions with active halogen-containing compounds, e.g., 2-bromo-1-phenylethanone (7a), 2-bromo-1-p-tolyl-ethanone (7b), chloroacetone (10a), α -chloroacetylacetone (10b), and chloroacetic acid ethyl ester (13). The structure of the newly synthesized heterocyclic compounds were established based on the data of elemental analyses, IR, 1 H NMR, and mass spectra. 相似文献
19.
Teresa M.V.D Pinho e Melo Ana L CardosoAntónio M.d'A Rocha Gonsalves 《Tetrahedron》2003,59(13):2345-2351
The dehalogenation of 2-halo-3-phenyl-2H-azirine-2-carboxylates is described. Using sodium borohydride and tributyltin hydride 3-phenyl-2H-azirine-2-carboxylates were obtained in moderate yields. The synthesis of a new 2-bromo-2H-azirines with a chiral auxiliary, 10-phenylsulfonylisobornyl 2-bromo-3-phenyl-2H-azirine-2-carboxylate, is reported. Its dehalogenation led to 10-phenylsulfonylisobornyl 2H-azirine-2-carboxylate as single stereoisomer together with the formation of 10-phenylsulfonylisobornyl acetate. 相似文献
20.
Antonio SalgadoYves Dejaegher Guido VerniestMark Boeykens Christine GauthierChristelle Lopin Kourosch Abbaspour TehraniNorbert De Kimpe 《Tetrahedron》2003,59(13):2231-2239
Several 1-alkyl-2-methylazetidin-3-ones were prepared in good yield by the hydride-induced cyclization of the corresponding β-bromo-α,α-dimethoxyketimines, the resulting 3,3-dimethoxyazetidines being hydrolyzed by acid. Imination of these 1,2-disubstituted azetidin-3-ones, followed by alkylation under kinetic control conditions resulted in regioisomeric mixtures of 2,4- and 2,2-dialkylated compounds. Analytical samples of the major 2,4-disubstituted derivatives were obtained after extensive chromatographic separation. The cis stereochemistry of the major 2,4-dialkylated isomer was demonstrated on the basis of NMR data. 相似文献