共查询到20条相似文献,搜索用时 15 毫秒
1.
Nouria A. Al-Awadi Bobby J. George Hicham H. Dib Maher R. Ibrahim Yehia A. Ibrahim Osman M.E. El-Dusouqui 《Tetrahedron》2005,61(34):8257-8263
Gas-phase pyrolysis (static and FVP) of 1-aroylbenzotriazoles gave the corresponding substituted benzoxazole, benzimidazole, benzamide, N-phenylbenzamide, phenanthridin-6(5H)-one derivatives and 1-cyanocyclopentadiene. The present kinetic and mechanistic findings also provide further evidence of the involvement of biradical or carbene reactive intermediates in the reaction pathway of gas-phase pyrolysis of benzotriazoles. 相似文献
2.
Gas-phase thermolysis of thieno[3,2-e][1,2,4]triazines gave benzonitrile, isothiazole, pyrimidine, [1]benzothieno[2,3-d]pyrimidine and thieno[3,2-d]thiazole derivatives. A mechanism of these pyrolytic transformation was proposed. Two new and efficient syntheses of the starting thieno[3,2-e][1,2,4]triazines were reported. 相似文献
3.
Sigitas Tumkevicius Linas LabanauskasVirginija Bucinskaite Algirdas BrukstusGintaras Urbelis 《Tetrahedron letters》2003,44(35):6635-6638
(1-Amino-1H-benzimidazol-2-yl)methanol 1 with thionyl chloride at reflux afforded 3-chlorobenzimidazo[1,2-c][1,2,3]thiadiazole 4, which reacted with various nucleophiles to give different products depending on the nature of the solvent. The structures of 4 and di(benzimidazo[1,2-c][1,2,3]thiadiazol-3-yl)sulfide 8 were confirmed by single-crystal X-ray analysis. 相似文献
4.
-Benzotriazolylamides 6a–d afforded N-(benzotriazol-1-ylmethyl)arylimidoyl chlorides (4a–d), which reacted in situ with potassium tert-butoxide to form 3-aryl-1,2,4-triazolo[1,2-a]benzotriazoles (7a–d) (44–68%), representatives of a novel heterocyclic system. The structure of 7a was confirmed by single crystal X-ray analysis. 相似文献
5.
Hanan Al-Awadi 《Tetrahedron》2005,61(44):10507-10513
FVP pyrolysis of 1-acylnaphtho[1,8-de][1,2,3]triazines at 500 °C and 10−2 Torr gave exclusively the corresponding 2-substituted naphtho[1,8-de][1,3]oxazines. The latter was also obtained by static pyrolysis but in lower yield along with the corresponding N-(naphthalen-1-yl)acylamides. The reaction was studied kinetically and mechanistically. 相似文献
6.
The synthesis of novel 1,2-benzoselenazin-4-ones which are six-membered homologues of ebselen, is described in order to evaluate their glutathione peroxidase-like activity. 相似文献
7.
Jilong Gao Jiaoyan ZhuLubin Chen Yingying ShaoJiaqi Zhu Yijia HuangXiaoxia Wang Xin Lv 《Tetrahedron letters》2014
A variety of benzo[d]benzo[4,5]imidazo[2,1-b]thiazoles were efficiently and conveniently synthesized from the Cu-catalyzed domino coupling of o-dihaloarenes with 2-mercaptobenzimidazoles. The reaction is also applicable to a series of multi-functional substrates, affording the halo-containing products with excellent selectivity. The brominated products can further react with arylboronic acids under Pd catalysis to furnish the aryl-substituted benzimidazo[2,1-b]benzothiazole derivatives. 相似文献
8.
In search of new lead structures for potent allosteric enhancers of antagonist binding to muscarinic M2 receptors, a novel heterocyclic ring system, 6,7,14,15-tetrahydro-15aH-azocino[1,2-a:6,5-b′]diindole, has been synthesized. The new ring skeleton was obtained from indol-2-yl-acetic acid in three steps. 相似文献
9.
A new class of 2-arylamino-dihydroxyindenopyrroles were prepared by the one-pot multicomponent reaction of ninhydrin, N-methyl-1-(methylthio)-2-nitroethenamine and aromatic amines in EtOH at room temperature. The advantages of this procedure are short reaction times, good to high yields, easy separation of products and good functional group tolerance. 相似文献
10.
11.
An efficient synthesis of novel spiro 2,3,7,8-tetrahydro-benzo[1,2-b:5,4-b′]dipyran-4,6-dione and 2,3,8,9-tetrahydro-benzo[1,2-b:4,3-b′]dipyran-4,10-dione derivatives in high yields under microwave irradiation is described. The reaction was also studied under conventional heating conditions. 相似文献
12.
Partha S. Ray Joan Buote Charles A. Webster Michael J. Manning 《Journal of heterocyclic chemistry》1993,30(1):45-48
Synthesis of pyridazino[1,2-a][1,2,4]benzotriazin-6-one derivatives involving reaction of either 1,2,3,6-tetra-hydropyridazine ( 9 ) or hexahydropyridazine 14 with 2-fluoro-5-nitrophenylisocyanate ( 5 ) to give, via intramolecular cyclization, 3a and 16 respectively is described. Compound 3a was converted to 18 via methylation and hydroxylation to give 20 followed by conversion to the acetonide derivative 18 . Both 16 and 18 were reduced to the amino derivatives 17 and 19 respectively. 相似文献
13.
Mahalingam Poornachandran 《Tetrahedron》2006,62(48):11274-11281
The synthesis of a new class of spirooxindolo pyrrolidines and spirooxindolo thiapyrrolizidines has been accomplished by a three component, one-pot 1,3-dipolar cycloaddition reaction. The cycloaddition was found to be highly regioselective. 相似文献
14.
Suresh Kumar Mondal Susanta Kumar Manna Arabinda Mandal Shubhankar Samanta Jayanta K. Ray 《Tetrahedron letters》2014
A convenient and efficient procedure has been developed for the synthesis of a new ring system, pyrrolo[1,2-b]pyrazolone, via two-component coupling reaction followed by base mediated intramolecular cyclization. Single-pot synthesis replacing the two step process has also been successfully carried out. A series of polycyclic pyrrolo[1,2-b]pyrazolone derivatives have been obtained by employing the procedure along with some fused pyrrol-1-ylamine system. The products were formed very rapidly in catalyst free condition in a good yield (up to 75%) and also it had tolerance to a wide scope of substrates. 相似文献
15.
Thoraya A. Farghaly 《Tetrahedron》2010,66(14):2700-2704
A simple synthetic strategy is described for the hitherto unreported 3-arylazo-8H-imidazo[1,2-b]pyrazolo[4,3-d]pyridazines 7 is described based on the reaction of 3-acetyl-4-cyano-1,5-diphenylpyrazole hydrazone 3 with the hydrazonoyl halides 1a-l. The structures of such dyes were confirmed by spectroscopic and X-ray crystallographic analyses. The mechanism of formation of such compounds was also discussed. 相似文献
16.
H. HayourA. Bouraiou S. BouacidaF. Berrée B. CarboniT. Roisnel A. Belfaitah 《Tetrahedron letters》2011,52(38):4868-4871
A new series of tacrine (9-amino-1,2,3,4-tetrahydroacridine) analogues consisting of a cycloalka[e]pyrano[2,3-b]pyridine linked to a quinolyl ring has been synthesized. These compounds were prepared from the appropriately substituted pyran derivative via a Friedländer reaction with selected cycloalkanones in high yields. Single crystal X-ray structures are reported for four compounds. 相似文献
17.
Hamdy A. Hammouda Ahmed M. El-Reedy Mohie A. F. Sharaf A. M. Abdel-Fattah 《Journal of heterocyclic chemistry》1984,21(2):337-339
1,8-Naphthosultam (I) coupled with arenediazonium salts to give the 4-arylazo- VII, and the 2,4-bisarylazo-1,8-naphthosultams, VIa-c. On the other hand, coupling of the 4-substituted 1,8-naphthosultams afforded the 2-phenylazo derivatives, IIa,b. Reduction of IIa,b gave the 2-amino compounds IVa,b, which reacted with nitrous acid to give the [1,2]benzisothiazolo[2,3,4-cde]benzotriazoles, Va,b, establishing thus a new ring system. The nitro analogue Vc was also synthesized. 相似文献
18.
Doug Vaughan 《Tetrahedron letters》2009,50(41):5709-5712
Reaction of 2,2-dialkylacetaldehydes with electron-rich 2-naphthols in presence of p-TSA under closed-vessel solvent-free microwave irradiation conditions resulted in formation of corresponding dihydronaphtho[2,1-b]furans in good to excellent yields. In several cases, small amounts of 14-alkyl-14H-dibenzo[a,j]xanthenes were also formed. 相似文献
19.
Iryna O. Yaremchuk Lyubov V. Muzychka Oleg B. Smolii Olexandr V. Kucher Svitlana V. Shishkina 《Tetrahedron letters》2018,59(5):442-444
The iodolactonization product obtained from methyl 7-allylpyrrolo[2,3-d]pyrimidine-6-carboxylate was used for the synthesis of novel 1,2-dihydropyrrolo[1,2-a]pyrazin-1(2H)-one derivatives, containing carboxamide- and methylamine-groups on the pyrrole ring of the heterocycle. 相似文献
20.