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1.
N. A. Keiko L. G. Stepanova I. D. Kalikhman M. G. Voronkov 《Chemistry of Heterocyclic Compounds》1976,12(10):1094-1097
The conditions of heteropolar and radical thiylation of 2-formyl-2,5-diethoxy-2,3-dihydro--pyrans were studied. Oxidation of the carbonyl group occurs along with the Cannizzaro reaction in the reaction of 2-formyl-2,5-diethoxy-2,3-dihydro--pyran with silver oxide in alkaline media. Oxidation of 2-formyl-2,5-dibutylthio-2,3-dihydro--pyran with silver oxide leads to stable 2,5-dibutylthio-2,3-dihydro--pyran-2-carboxylic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1319–1322, October, 1976. 相似文献
2.
The Michael condensation in the series of 5-aryl-3H-furan-2-ones with chalcones containing electron-donating substituents was studied. In the case of ,-unsaturated ketones containing an electrondonating substituent, the reaction does not stop at the stage of formation of 1,5-dicarbonyl compounds but is accompanied by intramolecular cyclodehydration yielding a new series of furo[2,3-b]-4H-pyrans. A mechanism of formation of these products was suggested. The structure of reaction products was proved by IR and 1H NMR spectroscopy. 相似文献
3.
M. A. Haimova M. D. Palamareva C. I. Novkova B. J. Kurtev C. A. Petrova T. I. Arnaudov 《Monatshefte für Chemie / Chemical Monthly》1970,101(3):855-865
Zusammenfassung Durch Umsetzung von Hydramiden mit am aromatischen Ring m,p-dialkoxysubstituierten Arylessigsäureestern in Gegenwart von wasserfr. AlCl3 entstehen Gemische aus Estern der (±)-erythro- und (±)-threo-3-Amino-2,3-diarylpropansäuren. Bei der Umsetzung von Piperonalhydramid mit dem Methylester der Homoveratrumsäure konnte lediglich daserythro-Diastereomere isoliert werden.Die diastereomeren Ester wurden zu den jeweiligen (±)-erythro- und (±)-threo-3-Amino-2,3-diaryl-1-propanolen reduziert, die als N,O-Dibenzoylderivate charakterisiert wurden. Ihre relativen Konfigurationen und die der zugehörigen Ester wurden auf Grund der IR-Spektren der diastereomeren Aminopropanole bestimmt. Die NMR-Spektren eines Diastereomerenpaares von Aminopropanolen bestätigen die ihnen chemisch zugeordneten Konfigurationen und ermöglichen den Nachweis auch ihrer bevorzugten Konformationen.
Synthesis and configuration of methyl esters of the diastereomeric (±)-3-amino-2,3-diarylpropanoic acids, the (±)-3-amino-2,3-diaryl-1-propanols and their derivatives
Reaction of hydramides with m,p-dialkoxysubstituted arylacetates in the presence of anhydrous AlCl3 generally leads to mixtures of the esters of the (±)-erythro- and (±)-threo-3-amino-2,3-diarylpropanoic acids. However, in the reaction of piperonal hydramide with methyl homoveratrate, only the correspondingerythro-diastereomer was obtained.Reduction of the diastereomeric esters gives the corresponding (±)-erythro- and (±)-threo-3-amino-2,3-diaryl-1-propanols, which can be characterized as N,O-dibenzoyl derivatives. Relative configurations of both alcohols and esters were determined by means of their IR spectra. Configurations were confirmed for one pair of diastereomeric amino alcohols by means of NMR spectra and preferred conformations deduced.相似文献
4.
O. A. Sof''ina N. M. Igidov E. N. Koz''minykh N. N. Trapeznikova Yu. S. Kasatkina V. O. Koz''minykh 《Russian Journal of Organic Chemistry》2001,37(7):1017-1025
Acylpyruvic acids readily react with 2,3-diaminopyridine to form (Z)-3-acylmethylene-1H-3,4-di- hydropyrido[2,3-b]pyrazin-2-ones. 5-Aryl-2,3-dihydrofuran-2,3-diones which can be regarded as lactones derived from -enolized aroylpyruvic acids react with 2,3-diaminopyridine under mild conditions, yielding regioisomeric (Z)-2-aroylmethylene-4H-1,2-dihydropyrido[2,3-b]pyrazin-3-ones. The structure of the products and reaction chemoselectivity are discussed. 相似文献
5.
The kinetics of the thermal decomposition of 2,3-dimethyl-3-pentyl acetate have been studied at a temperature range of 212–260°C and a pressure range of 30–300 mm Hg. The olefins produced are 2-ethyl-3-methyl-1-butene, 3,4-dimethyl-trans-2-pentene, 3,4-dimethyl-cis-2-pentene, and 2,3-dimethyl-2-pentene. The reaction is homogeneous, obeys first-order law, and the value of the rate constant is given by the Arrhenius equation The directions of elimination and their corresponding partial rates are best explained in terms of purely steric factors. 相似文献
6.
Conclusions 2,3-O-Isopropylidene-5-iodo-5,6-didesoxy--methyl-D-allofuranoside, obtained earlier from the reaction of (PhO)3P·CH3I with 2,3-O-isopropylidene--methyl-L-rhamnopyranoside, was synthesized.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 696–697, March, 1970. 相似文献
7.
The acylation of benzo[b]furan-, benzo[b]thiophene, and indolyl-3-acetic acid arylamides using acetic anhydride in the presence of 70% perchloric acid occurs at the -position of the heterocycle to give 2-acetylbenzo[b]furan-, 2-acetylbenzo[b]thiophene, and 2-acetylindolyl-3-acetic acid arylamides. Depending on the amount of perchloric used in the reaction they undergo cyclodehydration to 3-arylamino-1-methylhetero[2,3-c]pyrilium salts and to N-aryl-1-methyl-3(2H)hetero[2,3-c]pyridones. 相似文献
8.
9.
Zusammenfassung 2-Methylthio-benzophenon reagierte mit Chloressigsäure zu 3-Phenyl-benzo[b]thiophen-2-carbonsäure und mit -Chlorphenylessigsäure zu 2,3-Diphenyl-benzo[b]thiophen. 3-Phenyl-5-methoxy-benzo[b]thiophen-2-carbonsäure wurde aus 3-Phenyl-5-amino-benzo[b]thiophen-2-carbonsäure durch Verkochen des Diazoniumsalzes und Methylierung erhalten; ihr N-Methylpiperazid sowie 3 basisch substituierte Ester wurden dargestellt.
Derivatives of 3-phenylbenzo[b]thiophene
2-Methylthio-benzophenone reacted with chloroacetic acid to 3-phenyl-benzo[b]thiophene-2-carboxylic acid and with -chloro-phenylacetic acid to 2,3-diphenyl-benzo[b]thiophene. 3-Phenyl-5-methoxy-benzo[b]thiophene-2-carboxylic acid was prepared by diazotation of 3-phenyl-5-amino-benzo[b]thiophene-2-carboxylic acid and hydrolysis to the hydroxy compound followed by methylation; its N-methylpiperazide and three esters with basic substituents were synthesized.相似文献
10.
Previously unknown cis-1-(1-adamantyl)-2,3-epoxy-3-R-propanones were highly selectively obtained by epoxidation of ,-unsaturated ketones with hydrogen peroxide in alkaline medium. The regioselectivity of the epoxide ring cleavage with amines (piperidine and morpholine) was studied. 相似文献
11.
The reaction of 5,7-dichloro-6-nitropyrido[2,3-d]-pyrimidine-2,4-dione with amines gave products of the substitution of one or two chlorine atoms by ammo groups. The catalytic reduction of 6-nitro-5,7-disubstituted pyrido[2,3-d]pyrimidines with hydrogen over palladium oxide on carbon leads to 5,6-diamino- and 5,6,7-triaminopyridopyrimidines, the reaction of which with amyl nitrite in acetic acid gives triazolo(4,5:4,5) pyrido[2,3-d]pyrimidines.For communication 6 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 398–401, March, 1993. 相似文献
12.
Zusammenfassung Die Umsetzung des Benzylidenanilins mit Phenylessigester in Gegenwart von Natriumäthylat ergibt in der Hauptsache den Äthylester der (±)-erythro-3-Anilino-2,3-diphenylpropansäure in geringerer Ausbeute als dies bei Verwendung von wasserfr. AlCl3 der Fall ist. In Gegenwart von NaNH2 gelingt es hingegen, Ausbeuten anerythro-Isomerem über 70%d. Th. zu gewinnen. Die letztgenannte Umsetzung läßt sich auch mit denSchiffschen Basen aus Benzaldehyd und p-Toluidin, p-oder m-Chloranilin verwirklichen. Die relativen Konfigurationen der durch alkalische Verseifung ihrer Ester erhaltenen diastereomeren (±)-3-(Chloranilino)-2,3-diphenylpropansäuren sind deshalb diesen zuzuordnen, da ja nur diethreo-Isomeren beim Behandeln mit Benzolsulfochlorid in alkal. Lösung in die entsprechenden -Lactame übergehen. Durch Rückveresterung der freien Aminosäuren werden auch die Konfigurationen ihrer Ester bestimmt.
The reaction of benzylideneaniline with ethyl phenylacetate in the presence of sodium ethoxide yields ethyl (±)-erythro-3-anilino-2,3-diphenylpropanoate as main product, but in lower yield than when anhydrous AlCl3 is used. In the presence of NaNH2, however, a yield of more than 70% of theerythro isomer is obtainable. The latter reaction can also be carried out withSchiff's bases from benzaldehyde and p-toluidine or p-or mchloroaniline, respectively. The relative configurations of the diastereomeric (±)-3-(choloroanilino)-2,3-diphenylpropanoic acids, obtained by the alkaline hydrolysis of their esters, are assigned on the basis that only thethreo isomers yield -lactams, when treated with benzenesulfonyl chloride in a strongly alkaline medium. The configuration of the esters was determined by reesterification of the free amino acids.相似文献
13.
Abstract Cefpirome was synthesized in 37.7% overall yield from 3-chloromethyl-7-phenylacetylamino cephalosporanic acid p-methoxybenzyl ester (GCLE) by sequential substitution of C-3 chloride with iodide and 2,3-cyclopentenopyridine, followed by a one-pot procedure including deprotection of carboxyl group, hydrolysis of 7-phenylacetamido, and reaction with 2-mercaptobenzothiazolyl-(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate (MAEM). The reaction conditions were as follows: obtained from GCLE at low temperature (?5 to 0 °C) and absence of light, 3-iodomethyl-7-phenylacetylamino cephalosporanic acid p-methoxybenzyl ester (GILE) without purification was reacted directly with 2,3-cyclopentenopyridine, in which the molar ratio of GCLE, NaI, and 2,3-cyclopentenopyridine was 1:2:4, and the molar ratio of the resulting compound p-methoxybenzyl 7-phenylacetylamido-3-(2,3-cyclopenteno-1-pyridinio)methyl-3-cephem-4-carboxylate iodide and MAEM was 1:1.1. The structure of the intermediate and the target compound obtained were determined by nuclear magnetic resonance spectra and mass spectroscopy. 相似文献
14.
Quinoxalino[2,3-b]-1,4-thiazines were obtained by the reaction of 2-aminoquinoxaline-3-thione and its 6,7-dimethyl derivative with -halocarbonyl compounds. Hydrolysis of these compounds in alkaline and acid media gave 2-amino-3-quinoxalone and quinoxaline-2,3-dione. The IR and UV spectra are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 853–856, June, 1971. 相似文献
15.
José M. ConcellónCecilia Gómez 《Tetrahedron letters》2003,44(28):5323-5326
Ring-opening of 3-aryl-2,3-epoxyamides 1 was achieved by using samarium diiodide and D2O, yielding 3-aryl-3-deuterio-2-hydroxyamides 2 with total regioselectivity. The starting compounds 1 were easily prepared by reaction of the corresponding lithium or potassium enolates of α-chloroamides with aldehydes or ketones. When the reaction was carried out in the presence of H2O instead of D2O, the corresponding 3-aryl-2-hydroxyamides were isolated. The treatment of enantiopure 3-aryl-2,3-epoxyamides afforded optically active 3-aryl-2-hydroxyamides. 相似文献
16.
Novel spiro[1,3-benzodioxole-2,2-(2,3-dihydro-1H-pyrrol-3-ones)] were obtained from 2-aminomethylene-2,3-dihydropyrrol-3(1H)-ones and tetrachloro-1,2-benzoquinone in ethanol at room temperature. However, in addition, 3,4-dichloro-7-methoxy-5-(4-methoxyphenyl)-5,10-dihydrophenazine-1,2-dione was formed in the reaction of 1-(4-methoxyphenyl)-2-(4-methoxyphenylaminomethylene)-4,5-diphenyl-1,2-dihydropyrrol-3-one with tetrachloro-1,2-benzoquinone. 相似文献
17.
Albert Lévai József Jekő Tímea Gondos András Simon Gábor Tóth 《Journal of heterocyclic chemistry》2007,44(6):1453-1458
18.
Reaction of 3‐Hydroxyquinoline‐2,4‐diones with Inorganic Thiocyanates in the Presence of Ammonium or Alkylammonium Ions: the Unexpected Replacement of a Hydroxy Group by an Amino Group
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Antonín Klásek Ondřej Rudolf Michal Rouchal Antonín Lyčka 《Helvetica chimica acta》2015,98(3):318-335
3‐Hydroxyquinoline‐2,4‐diones react with KSCN in the presence of the NH$\rm{{_{4}^{+}}}$ ions to generate 2,3‐dihydro‐3‐thioxoimidazo[1,5‐c]quinazolin‐5(6H)‐ones, 2,3‐dihydro‐2‐thioxo‐1H‐imidazo[4,5‐c]quinolin‐4(5H)‐ones, and products of molecular rearrangement of the 3‐aminoquinolinedione intermediates. Starting compounds with a benzyl (Bn) group at C(3) afford 3‐aminoquinolinediones, even when only AcONH4 is used. The results of the reaction between 3‐hydroxyquinoline‐2,4‐diones and KSCN in the presence of BuNH2 show that replacing a OH group with a secondary NH2 group is also possible. 相似文献
19.
The [2+3] cycloaddition of Z-C,N-diphenylnitrone with E--nitrostyrenes leads to (3SR, 4SR, 5SR)- and (3SR, 4RS, 5RS)-2,3-diphenyl-4-nitro-5-arylisoxazolidines as the only reaction products. The kinetics of the reaction was studied by using the HPLC method. It was found that total rate constants increase with increasing substituent Hammett -constants. The substituent effect is rationalized in terms of FMO theory. 相似文献