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 234 毫秒
1.
Photocyclization of 3-chloro-N-phenylbenzo[b]thiophene-2-carboxamide 10 afforded [1]benzothieno[2,3-c]-quinolin-6(5H)-one 11 which was chlorinated to 6-chloro[1]benzothieno[2,3-c]quinoline 12 followed by dechlorination to give [1]benzothieno[2,3-c]quinoline 5 . A series of 6-substituted alkoxy and thioalkoxy[1]benzothieno[2,3-c]quinoline derivatives were prepared along with the N-methyl quaternary salt 13 of 5 . 6-Chloro[1]-benzothieno[2,3-c]quinoline 12 was converted into 6-hydrazino[1]benzothieno[2,3-c]quinoline 23 which upon treatment with formic acid yielded [1]benzothieno[2,3-c][1,2,4]triazolo[4,3-a]quinoline 6 . Treatment of 23 with nitrous acid resulted in [1]benzothieno[2,3-c]tetrazolo[1,5-a]quinoline 7 . Compounds 6 and 7 are novel heterocyclic ring systems.  相似文献   

2.
Derivatives of the following six ring systems were synthesized:
  1. 3,10-Dihydro-[1]benzothieno[2,3-d]imidazo[1,5-a]-pyrimidine (I)
  2. 6H-[1]Benzothieno[2,3-d]pyrazino[1,2-a]pyrimidine (II)
  3. 1,5-Dihydro-[1]benzothieno[2,3-d]imidazo[1,2-a]-pyrimidine (III)
  4. 6H-[1]Benzothieno[2,3-d]pyrimido[1,2-a]pyrimidine (IV)
  5. 1,5-Dihydro-imidazo[1,2-a]thieno[2,3-d]pyrimidine (V)
  6. 4H-Pyrimido[1,2-a]thieno[2,3-d]pyrimidine (VI)
The first four types are new heterocyclic systems. 2-Aminomethyl-5,6,7,8-tetrahydro-[1]benzothieno[2,3-d]pyrimidin-4(3H)-one (5), which was used as intermediate for typesI andII, was synthesized by various methods. TypesIII andIV were prepared from 2-methylthio-5,6,7,8-tetrahydro-[1]-benzothieno[2,3-d]pyrimidin-4(3H)-one via the corresponding 2-benzylamino derivatives, followed by ring closure.  相似文献   

3.
A study has been made of the reaction of 1,3-disubstituted bezothieno[2,3-c]pyrylium salts with hydrazine. It has been shown that 1,3-dialkyl-substituted benzothieno[2,3-c]pyrylium salts interact with hydrazine to give N-amino-1,3-dialkylbenzothieno[2,3-c]pyridines. The presence of a pyrylium ring on one of the positions of the phenyl group leads to a mixture of N-amino derivatives and 5H-[2,3]benzothieno[2,3-e]diazepines. In contrast, 1,3-diphenylbenzothieno[2,3-c]pyrylium perchlorate gives exclusively 5H-[2,3]benzothieno[2,3-e]diazepine.L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Tar Chemistry, National Academy of Sciences of Ukraine, Donetsk 340114. Translate from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp 1137–1140, August, 1998.  相似文献   

4.
Polysubstituted 2,3-dihydrofuro[2,3-b]pyridines and 3,4-dihydro-2H-pyrano[2,3-b]pyridines have been synthesized from 1,2,4-triazines using the inverse electron Diels-Alder reaction. For this purpose, 3-methylsulfanyl-1,2,4-triazines were reacted with several nucleophiles allowing the formation of appropriately substituted alkynes to undergo the intramolecular inverse electron demand Diels-Alder reaction. Sealed-tube microwave activation of the cycloaddition reaction has proved to be very efficient and allowed shorter reaction times. This strategy enabled an efficient synthesis of 3-hydroxy-2,3-dihydrofuro[2,3-b]pyridines and 4-hydroxy-3,4-dihydro-2H-pyrano[2,3-b]pyridines with several points of diversity on the bicyclic scaffold.  相似文献   

5.
A short and highly modular approach to various 4,5-diaminopyrrolo[2,3-d]pyrimidines and 2,4,5-triaminopyrrolo[2,3-d]pyrimidines was developed starting from 4-chloro-5-halopyrrolo[2,3-d]pyrimidines and 5-bromo-2,4-dichloropyrrolo[2,3-d]pyrimidine, respectively. Direct amination at the 5-position was achieved without the use of transition metals or other catalysts in 32-86% yield. Ten examples are given.  相似文献   

6.
Cycloaddition of 1,3-benzothiazole-2-selenenyl chloride to alkenes leads to 2,3-dihydrobenzo[d][1,3]selenazolo[2,3-b][1,3]thiazolium-4 derivatives.  相似文献   

7.
The fused heterocycles benzothiopyrano[2,3-b]indol-11-one and benzopyrano[2,3-b]indol-11-one, have been prepared from methyl 3-indole carboxylate in two steps.  相似文献   

8.
Synthetic approaches towards new condensed thienopyridine ring systems including furo[2,3-b]thieno[3,2-e]pyridines, bisthieno[2,3-b:3′,2′-e]pyridines, 5H-chromeno[2,3-b]thieno[3,2-e]pyridines, 5H-benzo(f)chromeno[2,3-b]thieno[3,2-e]pyridines have been achieved by application of intramolecular 4+2 cycloaddition reactions of suitably designed thieno[2,3-e][1,2,4]triazines tethered with alkene or alkyne terminals.  相似文献   

9.
In a three-step sequence starting from readily available starting materials, 2,3-carbon disubstituted furo[2,3-b]pyridines can be accessed in good yields and purity. Furo[2,3-b]pyridines bearing ester, amide and ketone groups at the 2-position can be prepared with a variety of aryl and alkyl groups at the 3-position.  相似文献   

10.
The first synthesis of the parent compound of the benzo[4,5]thieno[2,3-c]pyrrole ring system and its derivatives, as well as their Diels-Alder reactions with DMAD and N-phenylmaleimide are reported. A new synthesis of the benzo[4,5]thieno[2,3-d]pyridazine ring system is also described.  相似文献   

11.
A simple method for the synthesis of pyrrolo[2,3-c]carbazoles from N-alkylated-3-aminocarbazole derivatives and ethylene glycol has been developed via heteroannulation reaction using RuCl3/SnCl2 system. Moreover indolo[2,3-c]carbazoles were prepared from various pyrrolo[2,3-c]carbazoles in good yields.  相似文献   

12.
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   

13.
2-Hydroxy-4H-benzo[4,5]thiazolo[3,2-a]pyrimidin-4-one 2a and 7-hydroxy-5H-thiazolo[3,2-a]pyrimidin-5-one 2b, were obtained in high yields under mild conditions from the cyclization reactions of bis-(2,4,6-trichlorophenyl) malonate and 2-aminobenzothiazole or 2-aminothiazole, respectively. A new class of compounds, 2,3-dihydro-4H-benzo[4,5]thiazolo[3,2-a]furo[2,3-d]pyrimidin-4-ones and 6,7-dihydro-5H-furo[2,3-d]thiazolo[3,2-a]pyrimidin-5-ones, were synthesized via the microwave assisted radical addition of compounds 2a and 2b to various alkenes using manganese(III) acetate. A preliminary acetylcholine esterase (AchE) inhibition test of compound 4e showed excellent (92%) inhibitory potential, comparable with the standard drug Donapezil®.  相似文献   

14.
Cyclocondensation reaction of ethyl 7,8-diamino-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate with 1-methylisatin produced a separable mixture of the corresponding indolo[3,2-b]- and [2,3-b]pyrido[2,3-f]quinoxaline-3-carboxylates, of which the latter isomer predominates. On the other hand, interaction with 1H-isatin or 5-chloroisatin gave the respective indolo[2,3-b]pyrido[2,3-f]quinoxaline-3-carboxylates as the sole regiospecific products. The structures of these new pentacyclic derivatives are based on microanalytical, spectral (IR, MS, and NMR) and X-ray crystal structure data.  相似文献   

15.
The Smiles rearrangement was successfully applied to 4-hydroxybenzo[b]thiophene furnishing a facile entry to the 4-amino derivative. The rearrangement was extended to 5-methoxy-4-methoxycarbonyl[1]benzothieno[2,3-b]pyridine obtained via aza-Wittig/electrocyclization reaction of novel N-(4-methoxybenzothiophen-2-yl)iminomethyldiphenylphosphorane with methyl trans-4-oxo-2-pentenoate. The preparation of a novel 5-amino-4-methoxycarbonyl[1]benzothieno[2,3-b]pyridine, which is of interest as a potential secondary peptide structure mimic, was successfully achieved.  相似文献   

16.
Reduction of indolo[2,3-b]quinoxalines with zinc in the presence of an anhydride gave N,N-diacyl trapped 6,11-dihydroindolo[2,3-b]quinoxalines in 43-92% yields. When the reduction with zinc was performed in TFA/TFAA, an unexpected ring opened product was isolated in 49% yield. The structure of this product could be identified as 1,2-dihydro-1-trifluoroacetyl-3-[(2-trifluoroacetylamino)phenyl]quinoxaline.  相似文献   

17.
A versatile new approach for the synthesis in three steps of 2-substituted-2,3-dihydro[1,4]dioxino[2,3-b]pyridines B via a Smiles rearrangement using easily available reagents is described. A study illustrating the influence of experimental conditions on the progress of the reaction is reported.  相似文献   

18.
A microwave-assisted base-free intramolecular cross dehydrogenative coupling (CDC) of 3-aniline substituted coumarins and quinolinones have been developed. A broad range of indolo[2,3-c]coumarins and indolo[2,3-c]quinolinones can be easily afforded in good to high yields (up to 93%) under palladium catalysis. The method is among the most straightforward and convenient ways to access these fused polyheterocycles.  相似文献   

19.
A series of monomethoxy[1]benzothieno[2,3-c]quinolines 24-28 were prepared by photocylization of the appropriate 3-chloro-N-phenylbenzo[b]thiophene-2-carboxamides 9–13 to [1]benzothieno[2,3-c]quinolin-6(5H)-ones 14-18 followed by chlorination to 6-chloro[1]benzothieno[2,3-c]quinolines 19-23 then dechlorination resulting in the title compounds except for 25 which was achieved by direct reduction of 15 . Reaction of 24-28 with methyl iodide provided the corresponding N-methyl quaternary salts 29-33 . Also, conversion of 4-meth-oxy[1]benzothieno[2,3-c]quinolin-6(5H)-one 16 to 4-methoxy-6-methylthio[1]benzothieno[2,3-c]quinoline 35 and 4,6-dimethoxy[1]benzothieno[2,3-c]quinoline 36 is described.  相似文献   

20.
Chromones bearing electron-withdrawing substituents at the 2- or 3-position react with nonstabilized azomethine ylides to produce 1-benzopyrano[2,3-c]pyrrolidines in good yields. Reactions of 3-cyanochromones proceed diastereoselectively to give 1-benzopyrano[2,3-c]pyrrolidines and tetrahydro-1H-spiro[chromeno[2,3-c]pyrrol-9,5′-oxazolidine]-9a-carbonitriles, depending on the reactant ratio, as a result of a 1,3-dipolar cycloaddition of the azomethine ylide at the double bond and carbonyl group of the chromone system. The latter undergoes demethylenation and recyclization into a novel hexahydrochromeno[2,3-c:3,4-c′]dipyrrole tetracyclic system on heating with hydrochloric acid.  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