共查询到20条相似文献,搜索用时 15 毫秒
1.
A microwave‐assisted method for the synthesis of a variety of thiophene o‐aminoesters (2a–l) has been developed, starting from an appropriate aldehyde, methyl ketone or acetoacetate ester with ethyl cyanoacetate in the presence of elemental sulfur. 相似文献
2.
A general method for the preparation of 2‐(N‐Substituted)‐2‐imidazolines and 2‐(N‐Substituted)‐1,4,5,6‐tetrahydropyrimidines is described. These heterocycles can be synthesized from their respective anilines with 2‐chloro‐2‐imidazoline or 2‐chloro‐1,4,5,6‐tetrahydropyrimidine, generated in situ from imidazolidin‐2‐one and tetrahydropyrimidin‐2(1H)‐one activated by dimethyl chlorophosphate, in good to excellent yields. 相似文献
3.
L. Giribabu Ch. Vijay Kumar A. Surendar V. Gopal Reddy M. Chandrasekharam P. Yella Reddy 《合成通讯》2013,43(23):4141-4147
A novel, highly efficient, single‐step synthesis of subphthalocyanines using microwave irradiation of phthalonitrile and boron trichloride in 1‐chloronaphthalene was accomplished for the first time. This provides a new preparative method for the synthesis of subphthalocyanines with reduced reaction times and improved yields. 相似文献
4.
Fathy M. Abdelrazek 《合成通讯》2013,43(17):2251-2258
2‐Phenyl‐1,1,3‐tricyanopropene[α‐(cyanomethyl)benzylidene‐malononitrile] undergoes bromination with N‐bromosuccinimide (NBS) to afford 2‐phenyl‐1,1,3‐tricyano‐3‐bromopropene: [α(bromocyanomethyl)benzylidene malononitrile]. This bromo derivative undergoes reactions with sodium hydrogen sulfide, hydrazine hydrate, phenyl hydrazine, hydroxylamine hydrochloride, ethyl thioglycollate, urea derivatives, and cyanacetohydrazide to afford thiophene, 4H‐pyridazines, 4H‐oxazine and 4H‐thiopyran, N‐substituted pyrrole, and pyrrolo[1,2‐b]pyridazine derivatives respectively. 相似文献
5.
Different substituted 2‐chloromethylpyridyl derivatives (6a–d) were oxidized with mCPBA to give the respective 2‐chloromethylpyridine‐N‐oxide derivatives (7a–d) at low temperature, which on condensation with 2‐mercapto‐1H‐benzimidazole (8a–c) in the presence of aprotic solvents give the 2‐[[(pyridin‐2‐yl‐1‐oxide)methyl]sulfanyl]‐1H‐benzimidazole (9a–d) in good yield. Finally, 9a–d oxidized with mCPBA in chlorinated solvent gives a mixture of 2‐[[(pyridin‐2‐yl‐1‐oxide)methyl]sulfonyl]‐1H‐benzimidazole (3a–d, 10%) and 2‐[[(pyridin‐2‐yl‐1‐oxide) methyl]sulfinyl]‐1H‐benzimidazole (4a–d, 90%) derivatives. 相似文献
6.
Two series of 2,5-disubstituted thiophene derivatives (series 1: 2,5-bis(p-alkoxyphenylethynyl)thiophene and series 2: 2,5-bis[p-(p-alkoxyphenylethynyl)(phenylethynyl)]thiophene) were synthesized and characterized by ^1H NMR, ^13C NMR, HRMS and elemental analysis. The relationship between the structure and the mesogenic and spectroscopic properties has been discussed. The results show that compounds 1a-1f all exhibited an enantiotropic nematic mesophase, which was confirmed by the polarized optical microscopy (POM), differential scanning calorimeter (DSC) and variable temperature powder X-ray diffraction (PXRD). In contrast, the extended conjugated analogues 2a-2b had no liquid crystal properties. As for the spectroscopic properties, incorporating more phenylethynyl units results in red-shifted absorption and emission spectra, greatly enhanced quantum efficiency. 相似文献
7.
A series of weakly nucleophilic nitrogen derivatives including carbamates, amides, sulfonamides, and anilines were reacted with 1,2‐bis(trimethylsilyloxy)cyclobutene under acidic conditions to afford various substituted 2‐aminocyclobutanone derivatives 3a–i in modest to excellent yields. 相似文献
8.
Novel calix[4]azacrown derivatives from the reaction between calix[4]amidocrown and the different N‐(4‐bromoacetamidephthalimido)alkanes derivatives, which may be useful intemediate compounds of pseudorotaxane, have been synthesized and structurally characterized by IR, 1H NMR, 13C NMR, MS, and elemental analyses. From their analysis data, it was found that compounds 6a–d adopted a cone conformation. 相似文献
9.
A facile and efficient synthetic route to substituted 1,4‐dithiafulvalenes has been developed. The precursors 2 may be easily prepared from the reactions of β‐dicarbonyl compounds 1 with CS2 and 1,2,3‐tribromopropane under mild conditions. The elimination of HBr of 2 in basic media furnishes corresponding acetyl substituted 1,4‐dithiafulvalenes 3 in 85–93% yields. The aldol condensation reaction of 2 with various arylaldehydes affords alkenoyl substituted 1,4‐dithiofulvalenes 4 in high to excellent yields. 相似文献
10.
P. M. Veeresha Sharma 《合成通讯》2013,43(9):1381-1388
Various substituted 3‐phenylindole 2‐carboxylates (1a–c) were prepared according to the literature methods. These carboxylates (1a–c) on reaction with thiosemicarbazide yielded 5‐substituted‐3‐phenylindol‐2‐(1,2,4‐triazole‐3‐thione) (2a–c) on refluxing in pyridine for 8 h. The 5‐substituted‐3‐phenylindole‐2‐[1,2,4‐triazolo‐3‐thioacetic acid] (3a–c) were prepared from 5‐substituted‐3‐phenyl indole‐2‐[1,2,4‐triazole‐3‐thione] (2a–c) on reaction with an appropriate alkylating agent and sodium acetate in acetic acid. Further, (3a–c) were reacted with acetic anhydride to bring about a cyclocondensation reaction to yield 5‐substituted‐3‐phenylindol‐2‐thiazolo(2,3‐b)‐triazole (4a–c). The 5‐substituted‐3‐phenylindole‐2‐[1,2,4‐triazolo‐3‐acetic acid] (3a–c) were reacted with o‐phenylenediamino dihydrochloride in ethylene glycol to yield 5‐substituted‐3‐phenylindole‐1,2,4‐triazolo‐3′‐yl‐thiomethyl)benzimidazoles (5a–c). 相似文献
11.
A New and Efficient Synthesis of Wedelolactone Derivatives 总被引:1,自引:0,他引:1
A new and facile method based on an intermolecular cycloaddition was described for the synthesis of wedelolactone derivatives. 相似文献
12.
A novel and efficient strategy for the synthesis of 2‐substituted 4‐azaindoles from 2‐chloro‐3‐nitropyridine through Pd‐catalyzed Sonogashira cross‐coupling, followed by reduction and heteroannulation on t‐BuOK, is reported. 相似文献
13.
Naoyuki Masuda Osamu Yamamoto Masahiro Fujii Tetsuro Ohgami Ayako Moritomo Toru Kontani 《合成通讯》2013,43(17):2305-2316
Various N‐3‐alkylated thiazolidenesulfonamide derivatives were efficiently prepared by the direct endo‐selective alkylation of thiazolylsulfonamides. The effects of different bases and solvents were investigated, and the NaH–THF combination was found to be the most effective at conferring high yields and endo‐selectivity. 相似文献
14.
Georgia Tsolomiti 《合成通讯》2013,43(4):501-507
A simple and efficient method is described for the synthesis of new functionalized 2‐aminothiazoles, the 2‐aminothiazole‐4‐phenyl‐5‐acetamides 5, in 67–96% yields based on an application of the Hantzsch synthesis. The method involves the reaction of thiourea with 3‐benzoyl‐3‐bromo‐propionamides 4 prepared from the corresponding 3‐benzoylpropionamides 3. The tautomeric structure of the γ‐keto amides 3 and 6 is directly related to the present study, because 2‐aminothiazoles 5 are readily obtained from the corresponding open chain γ‐keto amides 3. 相似文献
15.
《Journal of carbohydrate chemistry》2013,32(2-3):71-82
Abstract Methyl 2‐acetamido‐4‐amino‐2,4,6‐trideoxy‐α‐D‐galactopyranoside (10) was synthesized from D‐glucosamine hydrochloride in eight steps in an overall yield of 31%. Key steps include the selective benzoylation at O‐3 of methyl 2‐acetamido‐2,6‐dideoxy‐α‐D‐glucopyranoside in 89% yield and the subsequent Mitsunobu reaction using diphenylphosphoryl azide as the azide source which proceeded in 92% yield. Di‐ and mono‐benzyloxycarbonyl derivatives of 10 were also prepared. 相似文献
16.
Svetlana A. Burova Russ N. Fitzgerald Byron S. Johnson Richard T. Matsuoka 《合成通讯》2013,43(18):3029-3039
A novel method for preparation of 1‐substituted benzimidazoles via reductive amination of ketones with N‐differentiated 1,2‐diaminobenzenes is described. The method appears to be general in application to acyclic and cyclic ketones, as well as heteroatom‐substituted cyclic ketones. 相似文献
17.
2‐Phenyl‐1,1,3‐tricyano‐3‐bromopropene 1 reacts with the aromatic amines 2a–f and 6a–c to afford the N‐substituted pyrroles 4a–d, the pyrrolo[1,2‐a]quinazoline derivatives 5a, b, and the diaza‐as‐indacene derivatives 7a–c and 8a–c, presumably via elimination of hydrogen bromide followed by cyclization of the formed acyclic intermediates. All structures are confirmed by analytical and spectral data. 相似文献
18.
Gabriel Navarrete‐Vázquez Hermenegilda Moreno‐Diaz Samuel Estrada‐Soto Mariana Torres‐Piedra Ismael León‐Rivera Hugo Tlahuext 《合成通讯》2013,43(17):2815-2825
A series of 2‐(substituted phenyl)‐1H‐benzimidazole derivatives with various 5‐and 6‐position substituents (‐H, ‐CH3, ‐CF3) were synthesized via microwave irradiation using a short synthetic route and Na2S2O5 as oxidant. This simple, fast, and efficient preparation of benzimidazole derivatives has been developed using readily available and inexpensive reagents (aldehydes and 1,2‐phenylenediamines) under solvent‐free conditions. 相似文献
19.
An efficient Baeyer–Villiger rearrangement of cyclobutanone derivatives was investigated. One-pot synthesis of keto-δ-lactone from the Baeyer–Villiger rearrangement products was developed. Meanwhile, the synthetic useful γ-lactone and butenolide derivatives could be easily prepared. 相似文献
20.
Inarecentreport',a-aminoalkylphosphonateswithpyrazoIemoietyshowedverygoodinhibitoryeffectsagainstplantvirus.Inaddition,a-aminoalkylphosphonicacidsserveforinhibitingenZymeactivity,bacterialgrowthandinagrochemistryasantifungalagents,herbicidesandplantregulators'.Thereforeconsideringthewideapplicationsofsuchcompoundsandthebioactivitiesofheterocycliccompoundsandureaderivatives,wedesignedtosynthesizealargevarietyofheterocyclicsubstitutedureidoalkylphosphonates3.Thereportedmethodforsynthesisofsubst… 相似文献