首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 218 毫秒
1.
2-Aryl-4-oxothieno[2,3-d]oxazine derivatives were synthesized. Opening of the oxazine ring to give 2-benzamidothiophene-3-carboxylic acid hydrazide derivatives is observed when these compounds are treated with hydrazine hydrate.See [1] for Communication 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 45–46, January, 1980.  相似文献   

2.
The mononitration of benz[e]-, benz[f]-, and benz[g]isatins and their tetrahydro derivatives was realized. It was established on the basis of an analysis of the 1H NMR and mass spectra that substitution takes place at position 5 in the derivatives of the [g] series and at the position adjacent to the NH group in derivatives of the [f] series and in the case of 6,7,8,9-tetrahydrobenz [e]isatin. This reaction path corresponds to the maximum electron density in the HOMO, calculated by the CNDO method. In benz[e]isatin, contrary to the general relationship and to the quantum-chemical prediction, the nitro group initially enters the ring annellated with the indole ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 60–65, January, 1989.  相似文献   

3.
The electronic spectra of linear benzo[g]quinoline, its 4-substituted derivatives, and some hydrogenated derivatives are examined and discussed.See [1] for communication IX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 662–665, May, 1972.  相似文献   

4.
Zirconaindene derivatives produced benzocyclobutadiene derivatives in situ in the presence of CuCl and 1,4-naphthoquinone, which afforded their dimers, 6a,10b-dihydrobenzo[a]biphenylenes and dibenzosemibullvalenes or dibenzo[a,e]cycloctenes.  相似文献   

5.
New polymethine dyes — selenonaphtheno[2,3-d]thiazole derivatives — were synthesized. It is shown that all of the synthesized dyes which have a selenonaphtheno[2,3-d]thiazole residue are more deeply colored than the corresponding 6,7-benzobenzothiazole and thionaphtheno[2,3-d] thiazole derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 459–461, April, 1971.  相似文献   

6.
Synthesis of various benzo-annulated indane-based α-amino acid (AAA) derivatives are reported via a [4+2] and [2+2+2] cycloaddition reactions as key steps. Here, o-xylylene based AAA moiety has been used as a reactive intermediate and by adopting this strategy various indane-based constrained AAA derivatives are prepared.  相似文献   

7.
Polymethine dyes — benzofuro[2,3-b]pyridine and selenonaphtheno[2,3-b]pyridine derivatives — were synthesized, and their spectral properties are discussed. Replacement of a vinylene group by an oxygen or selenium atom in one benzene ring of the 2-benzo[h]quinoline residue in the cyanines causes a large bathochromic shift of the absorption maxima of the dyes as compared with replacement by a sulfur atom. The dyes derived from benzofuro[2,3-b]pyridine derivatives are more deeply colored than the derivatives of both thionaphtheno[2,3-b]-pyridine and selenonaphtheno[2,3-b]pyridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp.1611–1614, December, 1972.  相似文献   

8.
A method is proposed for the synthesis of 5-acylamino-2,3-dimethylthiophene-4-carbaldehydes and 5-acylamino-2,3-tetramethylenethiophene-4-carbaldehydes by the formylation of the corresponding thiophenes using the Vilsmeier reaction. From the formyl derivatives obtained, previously unaccessible derivatives of thieno[2,3-b]pyridine, thieno[2,3-d]pyrimidine, and thieno[3′,2′∶5,6]pyrido[2,3-d]-pyrimidine have been synthesized.  相似文献   

9.
Short practical syntheses for five deuterium-labeled derivatives of dimethylallyl diphosphate (DMAPP) useful for enzymological studies are reported. These include the preparation of the C1-labeled derivatives (R)-[1-2H]3-methylbut-2-enyl diphosphate ((R)-[1-2H]1-OPP) and (S)-[1-2H]3-methylbut-2-enyl diphosphate ((S)-[1-2H]1-OPP), the C2-labeled derivative [2-2H]3-methylbut-2-enyl diphosphate ([2-2H]1-OPP), and the methyl-labeled derivatives (E)-[4,4,4-2H3]3-methylbut-2-enyl diphosphate ((E)-[4,4,4-2H3]1-OPP) and (Z)-[4,4,4-2H3]3-methyl-but-2-enyl diphosphate ((Z)-[4,4,4-2H3]1-OPP).  相似文献   

10.
Conformations of 3-borabicyclo[3.3.1]nonane derivatives have been studied by means of 1H and 13C NMR spectroscopy. With the aid of the coupling constants 3J(HH) and 13C chemical shifts it has been shown that all the derivatives of 3-borabicyclo[3.3.1]nonane with the trigonal boron atom studied are in a flattened double-chair conformation. In 3-borabicyclo[3.3.1]nonane derivatives with the tetra-coordinated boron atom and substituents at the 7α-position, the chair-boat conformation predominates, the boat conformation being characteristic of the cyclohexane ring; exceptions are the compounds with the internal donor—acceptor bond between the boron atom an 7α-substituent.  相似文献   

11.
Synthesis of the glutaraldehyde derivatives calix[n]arene (n = 4,6,8) (Calix[n]-GA) and using as cross-linkers for immobilization of Candida rugosa lipase (CRL) have been discussed in this paper. The amino functional calix[n]arene derivatives (Calix[n]-NH 2) were synthesized via reduction of dinitrile, hexanitrile and octanitrile derivatives of calix[n]arenes. These amino functional calix[n]arene derivatives (Calix[n]-NH 2) were converted to their aldehyde derivativatives with glutaraldehyde. The calix[n]arene derivatives were used in lipase immobilization in order to see the role of calix[n]arene binding site on the lipase activitiy and stability. The activity recovery of calix[n]arene-supported lipases (Calix[n]-CRL) based on the Calix[4]-CRL, Calix[6]-CRL and Calix[8]-CRL reaches to 53.5, 66.1 and 76.4%, respectively.  相似文献   

12.
4,11-Dihydroxyanthra[2,3-b]thiophene-5,10-dione (thiophenoquinizarine) and its 3-methyl derivative were obtained by the cyclization of quinizarin-2-yl derivatives of mercaptoacetaldehyde or mercaptoacetone in acid medium. 4,11-Dimethoxy-and 4,11-dibutoxyanthra[2,3-b]thiophene-5,10-dione were synthesized by the alkylation of the hydroxyl group in the synthesized anthrathiophenes with dimethylformamide dimethylacetal or butyl iodide respectively. Radical bromination of 4,11-dimethoxy-3-methylanthra[2,3-b]thiophene-5,10-dione, depending on the amount of N-bromo-succinimide taken, leads to the formation of 3-bromomethyl-or 3-dibromomethyl-4,11-dimethoxy-anthra[2,3-b]thiophene-5,10-diones. The action of sodium acetate on the obtained bromo derivatives with subsequent hydrolysis of the intermediate acetates led to the synthesis of 3-hydroxymethyl-or 3-formyl-4,11-dimethoxy-anthra[2,3-b]thiophene-5,10-diones. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1478–1485, October, 2007.  相似文献   

13.
Various derivatives of 2,3-dihydro[1,5]benzothiazepin-4(5H)-ones were synthesized. Alternative route for the synthesis of 5-dimethylaminoethyl-2,3-dihydro[1,5]benzothiazepin-4(5H)-ones and 4-dimethylaminopro-poxy-(2H,5H)-[1,5]benzothiazepines are described.  相似文献   

14.
The derivatives obtained by reaction of o-halonitrothiophenes with cyanoacetic and acetoacetic esters were converted to thieno[2,3-b]- and thieno[3,2-b]pyrroles by reductive cyclization.See [1] for communication VI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1628–1630, December, 1973.  相似文献   

15.
The thiocyanation of 5-acylaminothiophenes gives 4-thiocyanato derivatives, the intramolecular cyclization of which gives 2-acylaminothieno[2,3-d]thiazoles.See [1] for communication VIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1204–1205, September, 1974.  相似文献   

16.
2-Propylbenzo[d][1,3,2]dioxaborole and related derivatives are shown to initiate a range of radical reactions under mild conditions.  相似文献   

17.
The synthesis and antiviral evaluation of 6-amino- and 6-chloro-9-(exo-bicyclo[2.2.1]hept-2yl)-9H-purine derivatives with thiophene and tetrahydrothiophenes annelated to a norbornane moiety are described. The key step in the synthesis of derivatives with the symmetrically annelated thiophene was the Mitsunobu reaction of endo-4-thiatricyclo[5.2.1.02,6]deca-2,5-dien-8-ol with 6-chloropurine. The key alcohol was obtained by DDQ mediated aromatization of the corresponding tetrahydro derivatives, which were used for the preparation of the target tetrahydrothieno analogs. The key intermediate for the synthesis of derivatives with the asymmetrically annelated thiophene was 8-exo-azido-3-thiatricyclo[5.2.1.02,6]deca-2(6),4-diene, which was prepared from 5-exo-azido[2.2.1]heptan-2-one by aldol condensation with O-ethyl S-(2-oxoethyl) carbonodithioate, deprotection and cyclization. The target compounds were obtained by the construction of the purine base on an amine, which was obtained by LAH reduction of the key azide. The synthesized compounds were evaluated for antiviral and cytostatic activity.  相似文献   

18.
Convenient syntheses of the previously unknown complete set of six isomeric monomethyl derivatives of benzo[e]pyrene, 1-, 2-, 3-, 4-, 9- and 10-methylbenzo[e]pyrene, are described. Syntheses of 1-, 2- and 3-methylbenzo[e]pyrene were accomplished through reaction of 7H-benzanthrene (or its 1-Me derivative as appropriate) with 1, 3-bis(dimethylamino)trimethinium perchlorate (or its 1-Me derivative) followed by thermal electrocyclic ring closure accompanied by elimination and aromatization. The earlier claim16 that the analogous isomeric benzo[a]pyrene derivatives are principal products of reactions of this type is disproven. Synthesis of 3,6- and 4,5-dimethylbenzo[e]pyrene are also described. The structural assignments of all mono- and dimethyl benzo[e] pyrene products are supported by high resolution 270 MHz proton NMR spectra; the chemical shifts and coupling constants of all aromatic protons are fully assigned.  相似文献   

19.
Bisthiadiazinylmethane derivatives obtained from 1,2,6-thiadiazine 1,1-dioxides and formaldehyde, undergo unusual intramolecular cyclizations to thiadiazino [4,3-g] [2,1,3] benzothiadiazine tetraoxides. The structures of the newly synthesized compounds are discussed on the basis of 1H and 13C-NMR data and X-ray analysis.  相似文献   

20.
Heterocyclization of functionalized vinylic derivatives of imidazo[1,2-a]pyridines was explored experimentally and theoretically using semiempirical AM1 and ab initio methods. A range of functionalized vinylic derivatives (azido, amino, and carbodiimide groups) were prepared for conversion into pyrroloazaindoles 19-22, imidazo[1,x]-, (x = 5, 6, 7, 8), [2,6]-, and [2,7]naphthyridines 28-30, 35-38 by thermal reaction. In the case of vinylic groups in the 5 position, peri annulation also was observed. The experimental and theoretical data are compared and discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号