共查询到20条相似文献,搜索用时 31 毫秒
1.
Arasambattu K. Mohanakrishnan J. Arul Clement P. Amaladass V.S. Thirunavukkarasu 《Tetrahedron letters》2007,48(49):8715-8720
The synthesis of 1,3-disubstituted benzo[c]thiophene analogs incorporating benzo[b]thiophene/benzo[b]pyrrole units is described. 相似文献
2.
Manojit Pal 《Tetrahedron letters》2003,44(45):8221-8225
An efficient synthesis of 2-alkyl/aryl substituted benzo[b]furans/nitrobenzo[b]furans in water has been accomplished via Pd/C catalyzed reaction of o-iodophenols with terminal alkynes in the presence of PPh3, CuI and prolinol. This method can tolerate a variety of functional groups present in the alkynes as well as base labile nitro group in the o-iodophenols. The protocol does not require the use of a phase transfer catalyst or water-soluble phosphine ligands and is free from the use of any organic co-solvent. 相似文献
3.
J. Arul Clement 《Tetrahedron》2009,65(21):4113-5670
Synthesis of 1,3-disubstituted benzo[c]thiophene analogs incorporating heterocycles such as benzo[b]thiophene/1-hexylindole/benzo[b]furan and thiophene units is described. Optical and electrochemical studies of the benzo[c]thiophene analogs are also reported. 相似文献
4.
Yoshifumi Watanabe Hirotaka Yoshiwara Munefumi Kanao 《Journal of heterocyclic chemistry》1993,30(2):445-451
The syntheses of 4-(benzo[b]furan-3-yl)piperidines, 4-(benzo[b]furan-2-yl)piperidines and 4-(benzo[b]thiophen-3-yl)piperidines with 5-HT2 antagonist activity are described. Reaction of 1-acetyl-4-(2,4-difluorobenzo-yl)piperidine 2 with methyl glycolate gave methyl 6-fluoro-3-(1-acetylpiperidin-4-yl)benzo[b]furan-2-carboxylate 3 , which was converted to 2-[2-[4-(benzo[b]furan-3-yi)piperidin-1-yl]ethyl-5,6,7,8-tetrahydro-1,2,4-triazolo-[4,3-a]pyridin-3(2H)-one hydrochloride 9 . Analogous benzo[b]furans 17a-d and benzo[b]thiophenes 10a,b and 18a were prepared by a similar method. Cyclization of 4-fluoro-2-(4-pyridinylmethoxy)acetophenones 20a,b afforded 4-(benzo[b]furan-2-yl)pyridines 21a,b , which were converted to 2-[2-[4-(benzo[b]furan-2-yl)-piperidin-1-yl]ethyl-5,6,7,8-tetrahydro-1,2,4-triazolo[4,3-a]pyridin-3(2H)-one hydrochlorides 24a,b. Among them, benzo[b]furans 9 and 17a,d and benzo[b]thiophenes 10 and 18a showed potent 5-HT2 antagonist activity in vitro. 相似文献
5.
We describe here a novel synthesis of benzo[b]naphtho[2,3-d]furan-6,11-diones based on the heteroannulation of 2-(2-bromophenyl)-3-hydroxy-1,4-naphthoquinones. The naphthoquinones were prepared from 3-(2-bromophenyl)naphthalen-2-ols, which were obtained by intramolecular aldol condensation of 2-[3-(2-bromophenyl)-2-oxo-propyl]benzaldehydes. Alternatively, benzo[b]naphtho[2,3-d]furan-6,11-diones were obtained more directly and efficiently by cyclization of 3-(2-bromophenyl)naphthalen-2-ols to benzo[b]naphtho[2,3-d]furans and oxidation of the resulting compounds. Furthermore, the first 6-oxabenzo[a]anthracen-5-one described was similarly obtained from 2-[3-(2-formylphenyl)-2-oxopropyl]benzoic acid and oxidized to 6-oxa-benzo[a]anthracene-5,7,12-trione. 相似文献
6.
Novel fused heterocycles 1,10-dioxa-cyclopenta[a]fluorene and benzo[b]naphtho[2, 1-d]furans were synthesized via Dötz intramolecular benzannulation of alkyne tethered aryloxy chromium Fischer carbenes. 相似文献
7.
A new method was adopted for the synthesis of benzo[b]carbazoles by Claisen condensation followed by Fischer indole cyclization. Newly synthesized benzo[b]carbazoles were treated with ethanol amine in the presence of polyphosphoric acid which leads to the formation of pyrazino carbazoles. All the synthesized compounds were characterized by all spectral means. 相似文献
8.
3,4 - Di(methoxycarbonyl) - 5 - pyrrolidinobenzo[b]thiepin 5 is synthesized by a [2+2]cycloaddition of 3 - pyrrolidinobenzo[b]thiephene 3 to dimethyl acetylenedicarboxylate, with subsequent ring opening of the cyclobutene moiety in the intermediate 6,7-di(methoxycarbonyl)-5-pyrrolidino - 2 - thiabenzo[b]bicyclo[3.2.0]hepta - 3,6 - diene 4 (detectable by PMR spectroscopy at ?30°C). Hydrolysis of the pyrrolidino group in 5 affords 3,4 - di(methoxycarbonyl) - 5 - hydroxybenzo[b]thiepin 8. Peracid oxidation of 5 yields the corresponding 1,1-dioxide. The benzo[b]thiepins are thermally unstable and (depending on the substituents) either extrude sulphur or rearrange to a 4-mercapto-1-naphthol, probably via the thianorcaradiene as the intermediate. The kinetics of the latter reaction are discussed. On being irradiated, the benzo[b]thiepins isomerize to 2-thiabenzo[b]bicyclo[3.2.0]hepta-3,6-dienes. 相似文献
9.
Diarylamines in the benzo[b]thiophene series bearing electron donating or withdrawing groups, were prepared by Buchwald-Hartwig C-N coupling in moderate to high yields. The conditions used were Pd(OAc)2 (3 mol%), BINAP as ligand (4 mol%) and Cs2CO3 as base (1.4 equiv.), in toluene at 100°C, being 6-bromo or amino benzo[b]thiophenes coupled, respectively, with substituted anilines or phenylbromides. The 6-aminobenzo[b]thiophene derivatives were also prepared by palladium catalyzed C-N coupling of the corresponding 6-bromo compounds with benzophenone imine, followed by acidic hydrolysis of the imino derivatives. When 4-nitrobromobenzene and 4-bromobenzonitrile were used as coupling components, triarylamines were also isolated in small amounts. The presence of a fluorine atom on the phenylbromide highly increases the diarylamine yields. 相似文献
10.
Tadatsugu Yamaguchi Manabu HosakaToru Ozeki Masakazu MorimotoMasahiro Irie 《Tetrahedron letters》2011,52(43):5601-5604
Photochromic benzo[b]silole derivatives, 1-(1,1-dimethyl-2-phenylbenzo[b]silol-3-yl)-2-(2-phenylbenzo[b]thien-3-yl)perfluorocyclopentene and 1-(1,1-dimethyl-2-phenylbenzo[b]silol-3-yl)-2-(2-phenyl-1-benzofuran-3-yl)perfluorocyclopentene, were synthesized and their photochromic performance was examined in solution. 相似文献
11.
The photochemical behavior of several benzo[b]thiophenes 1–4 in neutral solutions or in the presence of primary and tertiary amines has been examined. In most cases, the photoformation of adducts or dimers, rather than cyclisation, has been observed. An unusual photocyclisation of a saturated compound 12 obtained by photolysis of 3 in a primary amine was observed 相似文献
12.
Antonella Bochicchio Maria Funicello Maria Teresa Lopardo Paolo Lupattelli 《Tetrahedron letters》2010,51(21):2824-971
Acetylation/Sonogashira cross-coupling reaction/cyclization has been carried out in one-pot using a Na2PdCl4/2-(di-tert-butylphosphino)-N-phenylindole/CuI system in TMEDA to give 5-nitro-2-substituted benzo[b]furans in excellent yields. We also describe the extension of this method to 4-EWG-2-bromo-phenols obtaining 2,5-disubstituted-benzo[b]furans in good yields. 相似文献
13.
Yoshinori Tominaga Ram Pratap Raymond N. Castle Milton L. Lee 《Journal of heterocyclic chemistry》1982,19(4):859-863
All isomers of the monomethylbenzo[b]naphth[2,1-d]thiophenes were synthesized using photocyclization of 3-styrylbenzo[b]thiophenes. The 1-, 3-, 4-, and 5-methylbenzo[b]naphtho[2,1-d]thiophenes were synthesized by irradiation of the corresponding methylated 3-styrylbenzo[b]thiophenes which were prepared by the Wadsworth-Emmons reaction of diethyl benzo[b]thenylphosphonate with o-, m-, p-tolualdehyde and acetophenone. The 7-, 8-, 9- and 10-methylbenzo[b]naphtho[2,1-d]thiophenes were synthesized by decarboxylation of 7-, 8-, 9- and 10-methylbenzo[b]naphtho[2,1-d]thiophene-6-carboxylic acid with copper in quinoline. These carboxylic acids were prepared by photocyclization of the corresponding 2-(benzo[b]thiophen-3-yl)-3-phenylpropenoic acids which were prepared by the condensation of the methylated benzo[b]thiophene-3-ylacetic acids with benzaldehyde in the presence of triethylamine in acetic anhydride. 相似文献
14.
Daniel Allen David R. Dobson John R. Harris Terry M. Hotten W. Martin Owton Richard E. Rathmell Virginia A. Wood 《Tetrahedron letters》2004,45(52):9645-9647
An easy and high-yielding method for the synthesis of substituted benzo[b]thiophenes using microwave irradiation is described. 相似文献
15.
A short, simple and inexpensive synthesis of several diversely substituted benzo[b]thiophenes and one naphthothiophene is described. The method involves introduction of methylsulfanyl group ortho- to the amide function of readily available N,N-diethylamides of aryl carboxylic acid by directed metalation. Thioindoxyls, obtained in high yields through side-chain deprotonation and cyclisation in one pot, are reduced to benzo[b]thiophene or napthothiophene. 相似文献
16.
An efficient and metal-free method was developed to synthesize 3-chalcogen benzo[b]furans via the iodine-mediated electrophilic cyclisation of 2-alkynylanisoles with disulfides or diselenides. In the presence of I2, various 3-sulfenylbenzofurans or 3-selenenylbenzofurans were obtained in moderate to high yields. 相似文献
17.
Kazuhiro Kobayashi Mai Horiuchi Shuhei Fukamachi Hisatoshi Konishi 《Tetrahedron》2009,65(12):2430-8872
A convenient synthesis of 3-arylbenzo[b]thiophenes utilizing an interrupted Pummerer reaction of 2-(1-arylvinyl)phenyl ethyl sulfoxides is described. Thus, treatment of these sulfoxides, which were readily prepared from 2-sulfanylphenyl ketones or 2-fluoro-5-methoxybenzaldehyde, with acetic anhydride at 100 °C afforded 3-arylbenzo[b]thiophenes in reasonable yields. 相似文献
18.
We report a new flexible method for the synthesis of 2-functionalized benzo[b]furans and indoles from readily available o-(2,2-dibromovinyl)-phenol, -aniline or -acetanilide using a tandem Pd-assisted cyclization-coupling reaction. 相似文献
19.
A series of 6-arylbenzothieno[3,2-c]quinolines were synthesised in three steps from benzo[b]thiophene. After a selective Heck-type coupling of benzo[b]thiophene with different o-nitroaryl bromides to obtain 2-(o-nitroaryl)benzo[b]thiophenes, corresponding 2-(benzo[b]thiophen-2-yl)anilines were involved in a Pictet-Spengler reaction to form the quinoline cycle. 相似文献
20.
Ya-Li Chen 《Tetrahedron letters》2007,48(13):2421-2425
Palladium-catalyzed [2+2+2] cyclotrimerization reactions between benzyne and oxadisilole fused oxabicyclic alkenes afforded the exo-adducts. Deoxygenation with BF3·OMe2 yielded mono- and bis-oxadisilole fused benzo[b]triphenylene. The photophysical properties of the oxadisilole fused benzo[b]triphenylenes were characterized. 相似文献