共查询到20条相似文献,搜索用时 15 毫秒
1.
A concise synthesis of 4-aryl-10-oxo-1,2,3,10-tetrahydro-9-thia-1,3a-diazadicyclopenta[a,g]naphthalene-6-carbonitriles 5a-f and 5-aryl-11-oxo-1,3,4,11-tetrahydro-2H-10-thia-1,4a-diaza-cyclopenta[b]phenanthrene-7-carbonitriles 5g-i has been delineated through ring transformations of the 2H-pyran-2-one 1, followed by photocyclization of product 4. 相似文献
2.
A novel and efficient regioselective synthesis of various arylated highly congested 7-aryl-5-methylsulfanylindan-4-carbonitriles (3a-f), methyl 7-aryl-5-methylsulfanylindan-4-carboxylates (10a-e) and 7-aryl-5-methylsulfanylindan-4-carboxylic acids (11a-e) through base-catalyzed reaction of 6-aryl-4-methylsulfanyl-2-oxo-2H-pyran-3-carbonitriles (1a-f) and methyl 6-aryl-4-methylsulfanyl-2-oxo-2H-pyran-3-carboxylates (9a-e) by cyclopentanone (2) has been delineated. The synthetic potential of 2-pyranone was explored further to generate molecular diversity using 6-aryl-4-sec-amino-2-oxo-2H-pyran-3-carbonitriles (7a-h), 5,6-diaryl-4-methylsulfanyl-2-oxo-2H-pyran-3-carbonitriles (5a,b) and methyl 5,6-diaryl-4-methylsulfanyl-2-oxo-2H-pyran-3-carboxylates (12a,b) as precursors for the ring transformation by cyclopentanone to assess the effects of substituents on the course of the reaction to obtain highly congested indans, 6,7-diaryl-5-methylsulfanylindan-4-carbonitriles (6a,b), 7-aryl-5-(piperidin-1-yl)indan-4-carbonitriles (8a-h) and methyl 6,7-diaryl-5-methylsulfanylindan-4-carboxylates (13a,b). 相似文献
3.
A concise synthesis of some new classes of heterocycles (4-aryl-11-oxo-1,2,3,11-tetrahydro-1,3a-diaza-cyclopenta[a]anthracen-6-carbonitriles and 5-aryl-12-oxo-1,3,4,12-tetrahydro-2H-1,4a-diazabenzo[a]anthracene-7-carbonitriles) has been developed by the ring transformation of suitably functionalized 2H-pyran-2-one with α-oxoketene cyclic aminals to intermediates (8-aroyl-5-aryl-2,3-dihydro-1H-imidazo[1,2-a]pyridine-7-ylidene)-acetonitriles and (9-aroyl-6-aryl-1,2,3,4-tetrahydropyrido[1,2-a]pyrimidin-8-ylidene)-acetonitriles) followed by their photocyclization either in CHCl3 or acetonitrile. This reaction was further explored for the synthesis of methyl 4-aryl-11-oxo-1,2,3,11-tetrahydro-1,3a,9-triaza-cyclopenta[a]anthracene-6-carboxylate, 4-aryl-11-oxo-1,2,3,11-tetrahydro-1,3a,9-triaza-cyclopenta[a]anthracene-6-carbonitriles, 5-aryl-12-oxo-1,3,4,12-tetrahydro-2H-1,4a,10-triazabenzo[a]anthracene-7-carbonitriles, 4-aryl-10-oxo-1,2,3,10-tetrahydro-9-thia-1,3a-diazadicyclopenta[a,g]naphthalene-6-carbonitriles and 5-aryl-11-oxo-1,3,4,11-tetrahydro-2H-10-thia-1,4a-diazacyclopenta[b]phenanthrene-7-carbonitriles from the similar reactions. 相似文献
4.
Ramendra Pratap 《Tetrahedron》2006,62(34):8158-8163
Substituent-controlled regioselective synthesis of highly functionalized 1,2-teraryls 3a-k has been achieved through ring transformation of 6-aryl-4-(pyrrolidin-1-yl/piperidin-1-yl)-2H-pyran-2-one-3-carbonitriles 1a-g by aryl acetones 2a-c in the presence of powdered KOH in DMF in very good yield. Under similar reaction conditions, 6-aryl-4-methylsulfanyl-2H-pyran-2-ones 5a-f afforded 1,7-diaryl-2-methyl-4H,5H-pyrano[3,4-c]pyran-4,5-diones 6a-j as major products and 3,4-diaryl-2-methyl-6-methylsulfanylbenzonitriles as minor constituents 7a-j. 相似文献
5.
An innovative synthesis of aryl tethered 1,3-dimethylimidazo[4,5-b]pyrazin-2-ones 4 and 6 has been delineated through base catalyzed ring transformation of 6-aryl-4-(piperidin-1-yl)-2H-pyran-2-one-3-carbonitriles 1 and methyl 6-aryl-4-methylsulfanyl-2H-pyran-2-one-3-carboxylates 5 with 7-acetyl-1,3-dimethyllumazine 2 with subsequent ring contraction of the fused pyrimidine to an imidazole ring. An additional product, methyl [6-(1,3-dimethyl-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyrazin-5-yl)-4-thiophen-2-ylpyran-2-ylidene]acetate 8b, was also isolated from the reaction of 5 and 2, as a minor constituent. 相似文献
6.
Abbas Rahmati 《Tetrahedron letters》2010,51(22):2967-2970
A one-pot, three-component condensation reaction of an aldehyde, 3-amino-5-methylpyrazole and ethyl cyanoacetate in ethanol to give 4-aryl-3-methyl-6-oxo-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine-5-carbonitriles, in high yields, at reflux, using a catalytic amount of p-toluenesulfonic acid, is described. 相似文献
7.
A concise and convenient synthesis of various partially reduced 6-sec-amino-1,2,3,4,7,8-hexahydro-, 6-sec-amino-1,2,7,8-tetrahydrobenzo[c]phenanthrene-5-carbonitriles, 6-sec-amino-3,4,7,8-tetrahydro-1H-benzo[c]phenanthrene-2-one-5-carbonitrile cycloalkene ketals, pendant with electron donor and acceptor substituents has been described through base catalyzed ring transformation of 2-oxo-4-sec-amino-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles by cyclohexanone, 2-cyclohexen-1-one, 1,4-cyclohexanedione monocycloalkene ketals. The acid catalyzed deketalation of 6-sec-amino-3,4,7,8-tetrahydro-1H-benzo[c]phenanthrene-2-one-carbonitrile ketals led to yield 6-sec-amino-3,4,7,8-tetrahydro-1H-benzo[c]phenanthrene-3-carbonitrile-2-ones in excellent yield. We also performed the X-ray studies of the molecules 3d and 6a to know the degree of non-planarity. 相似文献
8.
Farhanullah 《Tetrahedron letters》2007,48(46):8213-8216
An efficient and simple synthesis of highly congested 2-benzyloxy-3-benzyloxymethyl-5-sec-aminobiphenyl-4-carbonitriles 3a-e has been delineated through base catalyzed ring transformation of 6-aryl-4-sec-amino-2H-pyran-2-one-3-carbonitriles 1 by 1,3-bisbenzyloxypropan-2-one 2. Debenzylation of both the O-benzyl groups of 3a-e with boron trichloride provided the corresponding diols, 2-hydroxy-3-hydroxymethyl -5-sec-aminobiphenyl-4-carbonitriles 4a-e in very good yields. 相似文献
9.
Jéssica Venância Faria Maurício Silva dos Santos Percilene Fazolin Vegi Julio Cesar Borges Alice M.R. Bernardino 《Tetrahedron letters》2013
In this Letter, we described the synthesis of new 5-(5-amino-1-aryl-1H-pyrazole-4-yl)-1H-tetrazoles 2a–c from 5-amino-1-aryl-1H-pyrazole-4-carbonitriles 1a–c as well as the unexpected 1H-pyrazolo[3,4-d]pyrimidine derivatives 6a–c from 5-amino-1-aryl-3-methyl-1H-pyrazole-4-carbonitriles 4a–c, instead of 5-(5-amino-1-aryl-3-methyl-1H-pyrazole-4-yl)-1H-tetrazoles 5a–c as desired. In an attempt to obtain these tetrazole derivatives containing the methyl group at C3-position in the pyrazole ring, the amino group in 5-amino-1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile 4c was protected by the reaction with sodium hydride and di-tert-butyl-dicarbonate (Boc). The tetrazole derivative 5c was synthesized from the protected compound 7c using analogue methodology to obtain 2a–c and 6a–c. 相似文献
10.
3-(6-Phenylimidazo[2,1-b]thiazol-5-yl)quinoxalin-2(1H)-ones (qunoxalinone) (6a-q) have been synthesized by the reaction of ethyl 2-oxo-2-(6-phenylimidazo[2,1-b]thiazol-5-yl)acetates (4a-e) with suitably substituted o-phenylenediamines (5a-f) under microwave heating. The ethyl 2-oxo-2-(6-phenylimidazo[2,1-b]thiazol-5-yl)acetates (4a-e) were prepared by the reaction of 6-phenylimidazo[2,1-b]thiazoles (3a-e) with ethyl chlorooxoacetate in refluxing 1,4-dioxane whereas the thiazoles (3a-e) were synthesized by the reaction of 2-bromo-1-phenylethanones (2a-e) with thiazol-2-amine in refluxing acetone. 相似文献
11.
Chander Mohan 《Tetrahedron letters》2004,45(31):6075-6077
The synthesis and transformation of previously unknown 3-aryl-2-phenyl-5-prop-2-ynylsulfanyl-3H-pyrimidin-4-ones 3a-e to novel thieno[3,2-d]pyrimidin-4-ones 4a-e are reported. 相似文献
12.
Ramendra Pratap 《Tetrahedron letters》2007,48(10):1715-1719
An innovative and efficient route to the synthesis of 9,10-dihydro-3-formylphenanthrenes 7 has been delineated through the ring transformation of 2-oxo-4-sec-amino-5,6-dihydro-2H-benzo[h]chromene-3-carbonitriles 4 with methyl glyoxaldimethylacetal 5 to masked 3-dimethoxymethyl-1-sec-amino-9,10-dihydrophenanthrene-3-carbonitriles 6 followed by deacetalation with Amberlyst 15 in excellent yields. 相似文献
13.
Thermolysis of substituted methyl 1-methyleneamino-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates 2a,b led to substituted dimethyl 3,9-dioxo-1,5,7,11-tetrahydro-1H,7H-dipyrazolo[1,2-a;1′,2′-d][1,2,4,5]tetrazine-1,7-dicarboxylates 4a,b and methyl 2,5-dihydro-5-oxo-1H-pyrazole-3-carboxylates 5a,b as minor products. The structure of compound 4a was determined by X-ray crystallography. The proposed mechanism of this conversion includes generation of (N-methyleneamino)imidoylketenes 6a,b and its intramolecular transformation to azomethine imines—5-oxo-2,5-dihydropyrazole-1-methylium-2-ides 7a,b, which undergo dimerization in head-to-tail manner yielding products 4a,b and partially hydrolyse to compounds 5a,b. 相似文献
14.
The synthesis of phenyl, phenylsulfanyl and phenylselanyl substituted pyrano[3,2-c]chromenes 4 is accomplished via cyclocondensation of 4-oxo-4H-chromen-3-carbaldehydes 1 with appropriately substituted acetic acids 2 under mild conditions. Further treatment of 4 with alcohol or water led to 5-alkoxy- and 5-hydroxy-2H,5H-pyrano[3,2-c]chromen-2-ones 5 and 6, respectively. Acid and thermal catalysed rearrangement of 4-6 gave 5-hydroxypyrano[2,3-b]chromen-2(10aH)-ones 7 and their subsequent substitution led to 5-alkoxyderivatives 8. Reaction of 4 with amides led to 5-acylamino or 5-phenylsulfonamino substituted 2H,5H-pyrano[3,2-c]chromen-2-ones 9. Reactions were performed under heating or microwave irradiation. 相似文献
15.
Ouro-Sama Adetchessi 《Tetrahedron》2005,61(18):4453-4460
2-Substituted-4a-hydroxy-9H-cycloalkyl[1,2-e]oxazolo[3,2-a]pyrimidin-9-ones 2a-c were synthesized by an one-step cyclocondensation from the 5-substituted-2-amino-2-oxazolines 1a-c with ethyl 2-oxocyclohexanecarboxylate in ethanol at room temperature, and easily dehydrated to provide 2-substituted-9H-cycloalkyl[1,2-e]oxazolo[3,2-a]pyrimidin-9-ones 3. In refluxing xylene, the reaction conducted with various ethyl 2-oxocycloalkanecarboxylates led to the two isomeric 2-substituted-8/9H-cycloalkyl[1,2-e]oxazolo[3,2-a]pyrimidin-8/9-ones 3 and 2-substituted-5H-cycloalkyl[1,2-d]oxazolo[3,2-a]pyrimidin-5-ones 4. The structure of some compounds was unambiguously established using X-ray crystallography. According to results from the DSC analysis of compound 2a, formation of the thermodynamically stable pyrimidinones 4 could be related to an intramolecular rearrangement of kinetically controlled pyrimidinones 3. 相似文献
16.
A general controlled synthesis of oligoarenes and heteroarenes through base-catalyzed ring transformation of 6-aryl-4-(pyrrolidin-1-yl)-2H-pyran-2-one-3-carbonitriles (1a-d) and methyl 6-aryl-4-methylthio-2H-pyran-2-one-3-carboxylates (1e-h) is described. This procedure offers flexibility in the fabrication of diverse oligoarene ring systems in a controlled fashion. 相似文献
17.
Convenient synthesis of 7-aryl-3,4,5,6-tetrahydro-2H-pyrido[4,5-b]- and [2,3-b]-1,5-oxazocine-6-ones
Shigeki Seto 《Tetrahedron letters》2004,45(46):8475-8478
A convenient and diversity-oriented method for synthesis of the novel 7-aryl-3,4,5,6-tetrahydro-2H-pyrido[4,5-b]-1,5-oxazocine-6-one skeleton 1 and the very rarely described 7-aryl-3,4,5,6-tetrahydro-2H-pyrido[2,3-b]-1,5-oxazocine-6-one skeleton 2, featuring cyclization using nucleophilic aromatic substitution (SNAr) and Suzuki coupling, is described. 相似文献
18.
6-Arylidene-3-methyl-6,7,8,9-tetrahydro-5H-benzo[a]cyclohepten-5-ones (2a-h), obtained by the condensation of 3-methylbenzocyclohepten-5-one 1 with appropriate aromatic aldehydes, on reaction with Lawesson's reagent in xylene yielded phosphorus containing compounds 3a-h. A number of these compounds showed promising anti-inflammatory activity. 相似文献
19.
2-Alkoxyiminoimidazolidines 2-3 react with acetylene dicarboxylates and ethyl phenylpropiolate to give 8-alkoxy-imidazo[1,2-a]pyrimidin-5(3H)-ones C, which subsequently undergo a sterically induced multihetero-retro-ene fragmentation to give imidazo[1,2-a]pyrimidin-5(1H)-ones 4-7 together with formaldehyde or benzaldehyde. On the other hand, a similar reaction of 2-3 with ethyl propiolate gives corresponding 8-alkoxy-imidazo[1,2-a]pyrimidin-5(3H)-ones 8-10. The unsubstituted imidazo[1,2-a]pyrimidin-5(1H)-one 11 can be prepared by retro-ene reaction of 9 upon prolonged heating in refluxing ethanol. A direct synthetic approach to 1-formyl-7-phenyl-imidazo[1,2-a]pyrimidine-5(1H)-one 14 is reported using DMF/sulfonyl chloride as a new Vilsmeier-type N-formylating reagent. 相似文献
20.
An efficient regioselective synthesis of pyronyl pendant ethyl methylthiocarbonylalkanoates 5 has been delineated from the base catalyzed reaction of suitably functionalized 2-pyranone 1 and 2-carbethoxycycloalkanones 2, 6 through successive substitution and regioselective ring opening by in situ generated mercaptide ion. To assess the effect of C-4 substituent on regioselectivity, reactions of 6-aryl-3-cyano-4-(piperidin-1-yl)-2-oxopyran 8 with 2-carbethoxycyclohexanone 6a and 2-carbethoxy-2-methylcyclohexanone 6b were carried out separately under analogous reaction conditions but the compounds isolated were identical and characterized as 4-aryl-8-methyl-2-piperidin-1-yl-5,6,7,8-tetrahydronaphthalene-1-carbonitriles 9. Ethyl 2-(5-amino-4′-bromo-4,6-dicyanobiphenyl-3-yl)-5-methylsulfanylcarbonylpentanoate 10 has also been prepared through base catalyzed ring transformation of ethyl 2-[6-(4-bromophenyl)-3-cyano-2-oxo-2H-pyran-4-yl]-5-methylsulfanylcarbonylpentanoate 5d by malononitrile in DMF. 相似文献