Phase Transfer Catalyzed Synthesis of 1, 2-Bis[（3-aryl）-s-triazolo- [3, 4-b]-[1, 3, 4]thiadiazole-6-yl]ethanes

s-Triazolo[3, 4-b]-[1, 3, 4]thiadiazole derivatives have been paid attractive attention due to their significantly biological activities1-5, including antibacterial, antifungal, anticancer, relaxing vascular activities. They are highly important heterocyc…     

Synthesis, Crystal Structure and Antibacterial Activities of 3-[3-Methyl-（2-thienyl）methyl-enehydrazinocarbonyl]-（1H）-1,2,4-triazole

1 INTRODUCTION Azole derivatives, such as the derivatives of pyra- zole, imidazole, triazole including benzotriazole, te- trazole and indole, have extensive biological activi- ties. They have become the central focus of studies of agricultural chemicals, medicines, plant growth regulating agents and so on[1, 2]. Schiff bases also constitute a good type of biologically active sub- structures. Studies on pyrazole Schiff base-type fun- gicides have been reported[3, 4]. However, some struc- …     

A New Route to Synthesis of 3,6-Diaryl-1,2,4- triazolo [ 3,4-b ] 1,3,4-oxadiazoles

Various 1,2,4-triazoles and 1,3,4-oxadiazole derivatives have been reported to possess diverse biological activities.In addition to above biological activity, we coupled these two rings together to get 1,2,4-triazolo[3,4-b] 1,3,4-oxadiazole derivatives. This ring system was first reported in 1961[1] and synthesized in 1971.     

Syntheses and Crystal Structures of 4-Amino-3- （3-hyd roxyp ropyl）- 1H-1,2,4-triazole-5（4H）-thione and 6-（4-Biphenylyl）-3-（3-hydroxypropyl）-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazine

1INTRODUCTION It has been reported that3,6-disubstituted-7H-1,2,4-triazolo[3,4-b][1,3,4]thiadiazines have a broad spec-trum of bioactivities,such as antimicrobial[1],antibac-terial,antifungal[2],anti-inflammatory[3],diuretic[4],an-thelmintic and analgesic[5].They can also be used as plant-growth regulating agents[6],photographic coup-lers,dyes for improved preservability and absorption characteristics,and inhibitors of malignant cellularZOU K.H.et al.:Syntheses and Crystal Structures o…     

Studies on Condensed Heterocyclic Compounds(Ⅲ)——Synthesis and Antibacterial Activity of 3-(4-Pyridyl)-6-Alkyl/Aromatic Heterocyclyl-s-Triazolo[3,4-b]-1, 3,4-Thiadiazoles and 1,4-Bis [6-(4-Pyridyl)-s-Triazolo [3,4-b]-1, 3,4-Thiadiazol-3-yl]-n-Butane

In recent years, fused heterocycles have been reported to possess important properties in synthesis and pharmacology. Especially, s-triazolo, 3,4-thiadiazole derivatives have been attracting much attention for chemists and pharmacologists because they show broad spectra of biological activities, such as antifungal, antibacterial, hy-     

Synthesis of Novel Biologically Active s-Triazolo[3,4-b]-1,3,4-thiadiazole Derivatives

Heterocycles bearing a symmetrical triazole or 1,3,4-thiadiazole ring system are reported to show a broad spectrum of biological activities.[1,2] The 1,2,4-triazole nucleus has been recently incorporated into a wide variety of therapeutically interesting drugs including H1/H2 histamine receptor blockers, cholinesterase active agents, CNS stimulants, antianxiety and sedatives[3] Coumarins are nowadays an important group of organic compounds that used as bactericides, fungicides,anti-inflammatory, anticoagulant, anti-HIV and antitumour agents.[4,5] Keeping in view the biological importance of the above mentioned heterocyclic compounds and in continuation of our search for biologically active nitrogen and sulphur heterocycles, a series of s-triazolo[3,4-b]-1,3,4-thiadiazole derivatives was synthesized.     

Synthesis and Antibacterial Activity of 8-Substituted Phenyl-1-pyridin-3-yl-5H-bis[1, 2, 4]triazolo[3, 4-b； 4＇, 3＇-d][1, 3, 4] thiadiazines

To find new structural leading compounds for the research of the multidrug resistant of antibacterial agents, five novel 8-substituted phenyl-l-pyridin-3-yl-5H-bis[1, 2, 4] triazolo[3, 4-b;4‘,3‘-d] thiadiazines were prepared from the corresponding intermediates of 3-(5-substituted phenyl[1,3,4]oxadiazol-2-ylmethylsulfanyl)-5-pyridin-3-yl-[1,2,4]triazol-4-ylamines via intramolecular cyclization and the antibacterial activity in vitro against Gram-postive (G^ ) and Gramnegatiye (G) bacteria was primarily evaluated.     

Synthesis and Crystal Structure of 4-Salicyli deneamino-3-methyl-1,2,4-triazol-5-thione

1 INTRODUCTION 3-Substituted-4-amino-1,2,4-triazol-5-thione is the key synthon in the formation of heterocyclic compound. As a bifunctional agent, it can react with various electrophilic reagents and its derivatives have been reported to show various biological activities to be employed as fungicide[1], micro- biocide[2, 3], bactericide[4], herbicides[5] and anti in- flammatory agents[6]. Furthermore, 3-substituted-4- amino-1,2,4-triazol-5-thione has potential electron donors. Though ma…     

Synthesis and Crystal Structure of 1,7,7-Trimethyl- 4-（4-methoxyphenyl）-4,6,7,8-tetrahydroquinoline- 2,5（1H,3H）-diones under Microwave Irradiation

1 INTRODUCTION Various quinolone derivatives are known to dis- play interesting biological properties ranging from microbial activity to cytotoxicity[1]. They have been reported as antiviral (HIV-1)[2] and antitumor agents[3] as well as used as tubulin[4], topoisomerase[5] and thrombocyte inhibitors[6]. As a member of the quino- lone family, substituted N-phenyl-2-quinolones re-present the structural basis of many biologically active compounds, such as protein kinase inhibitors, immunodu…     

Synthesis and Crystal Structure of N-Hydroxy-9-(3’,4’-methylene- dioxyphenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9, 10-decahydroacridine in Aqueous Media

1 INTRODUCTION Acridine derivatives are described to have many applications, such as biological fluorescent probes[1] as well as anti-tumor[2], anti-bacterial[3], anti-HIV[4] and anti-malarial[5] agents. Because of the importance of acridine derivatives, much work has been done for several decades. Among them the classical synthetic methods involve condensing functionalized anilines and o-halogeno- benzoic acid derivatives as well as several other steps resulting in the desired acridine[…     

Design,synthesis and in vitro antibacterial activities of methyl-4-((substituted phenyl)[6H-indolo(2,3-b)quinoxalin-6-yl]methyl-amino)benzoate derivatives

A series of new methyl-4-((substituted phenyl)[6H-indolo(2,3-b)quinoxalin-6yl]methylamino)benzoate derivatives have been synthesized and assayed for their antibacterial activity on 9 different bacterial strains.Among the screened compounds 2e-2g exhibited potent inhibitory activity compared to standard drug employed,worth further investigation.     

Synthesis of Quinolone Analogues: 7-[(2S,4R)-2-Aminomethyl-4- hydroxypyrrolidin-1-yl] Quinolones

Quinolone antibacterial agents have emerged as one of the dominant classes chemotherapeutic drugs for the treatment of various bacterial infections1. We have focused our attention on the modification of the C-7 basic group of the quinolone which has been most varied. In 1987, Uno et al.2 reported that 3-hydroxypyrrolidine quinolones showed more active antibacterial activities than Norfloxacin in vivo. In 1998, Fujita et al.3 reported that 2-aminomethylpyrrolidine quinolones have the same …     

Synthesis and Crystal Structure of 2-(4’-Methylphenoxy)-5,8,9-trimethyl-3-phenyl Thieno[3′,2′:5,6]pyrido[4,3-d]pyrimidin-4-(3H)-one Hydrochloride

1 INTRODUCTION Pyrido[4,3-d]pyrimidine derivatives have pharma- ceutical activity and germicidal action[1~3]. So far, hundreds of tetrahydro- and octahydro-pyrido[4,3- d]pyrimidines have been synthesized as potential diuretic, antirheumatic and bacteriostatic drugs, but only a few of fully aromatic pyrido[4,3-d] pyrimi- dines are known. An important synthetic route to synthesize fully aromatic pyrido[4,3-d]pyrimidines is the condensation reaction of 4-aminonicotinic acid and amines[4]. Ho…     

Synthesis and Crystal Structure of 1,2-Bis(1-phenyl-3-methylthio- 4-iminopyrazolo[3,4-d]pyrimidin-5-yl) ethane

1 INTRODUCTION As purine analogs, pyrzolo[3,4-d]pyrimidines have anti-tumor[1], antibacterial[2] and anti-leukemic activities[3,4]. Few of these, however, have been studied for pesticidal activity. It is reported that some substituted pyrzolo[3,4-d]pyrimidines have good fungicidal activity[5~7]. These prompted us to study pyrazolo[3,4-d]pyrimidines analogs further. It is shown that two possible products can be formed in the reaction of ethyl N-pyrazolylformimidate with alkylamines as sh…     

Dimer of Bis[trans-5-methyl-2-[2-（4-methoxylphenyl） ethenyl]-benzoxazole]di-μ-nitratosilver（I）

1 INTRODUCTION We are presently involved in the synthesis and photodimerization of the analogues of trans-2-sty- rylbenzoxazole (BOEP), which have been widely reported as fluorescent whiteners and remedies[1]. Some structures of BOEP derivatives and thei…     

Synthesis and Structure of 6-(4- Fluorobenzylamino)-3-methylthio-1,5- diphenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one

1 INTRODUCTION It was reported that the pyrazolopyrimidinone derivatives play a very important role in the bio- chemistry of living cell. Many potential drugs[1～3] and agrochemicals[4, 5] have been modeled on the compound, and the study on derivatives …     

Synthesis and Structure of O-Ethyl S-Hydrogen Isoquinolin-1-ylcarbonothioimidate

1 INTRODUCTION Isoquinoline and its derivatives have attracted much attention due to their physiological and phar- macological activities including antibacterial, antitu- mor, etc[1~3]. A lot of investigations in this field have been focused on the syntheses and applications in physiology and pharmacy of isoquinoline and its derivatives[4, 5]. Recently, a novel class of 1-subs- tituted isoquinolines or triazoloquinazolines deriva- tives have been identified as potential antagonists for the…     

Synthesis and Antibacterial Activities of 4—Amino—3—（1—aryl—5—methyl—1,2,3—triazol—4—yl）—5—mercapto—1,2,4—triazoles／2—Amino—5—（1—aryl—5—methyl—1,2,3—triazol—4—yl）—1,3,4—

Treatment of 4-amino-3-(1-aryl-5-methyl-1,2,3-triazol-4-yl)-5-mercapto-1,2,4-triazoles/2-amino-5-(1-aryl-5-methyl-1,2,3-triazole-4-yl)-1,3,4-thiadiazoles with benzaldehyde,acetone and ω-bromoacetophenone was tested and compared.The title compounds Schiff bases,amides,imidazolo [2,1-b]-1,3,4-thiadiazoles and 7H-s-triazolo[3,4-b]-1,3,4-thiadiazines have been confirmed by elemental analyses,^1H NMR,IR and MS spectra.All the compounds have also been screened for their antibacterial activities against B.subtilis,S.aureus and E.coli.     

New Synthetic Method of Azuleno[1,2-c]thiophenes

On the viewpoints of physical and chemical properties and biological activities, syntheses of a variety of heterocycle-fused azulenes have been repoted.[1] Of them, thiophene-fused azulenes were prepared by using different types of stating materials as follows. Azuleno[2,1-b] thiophenes are readily obtained from the reactions of 2-chloroazulene derivatives with ethyl mercaptoacetate in a few steps in good yield by Matsui[2] and Yamane.[3] On the other hand, the first synthesis of azuleno[1,2-c]thiophenes was accomplished by the reaction of 3-methoxycarbonyl-2H-cyclohepta[b]furan2-one with morpholino enamine of 3-oxotetrahydro-thiophene followed by dehydrogenation in poor yield by Fujimori.     

Synthesis and cationic selectivity studies of novel calix[4]arene derivatives containing heteroatom at the lower rim

A series of calixarene derivatives 2―5 containing heteroatom at the lower rim have been synthesized. 1H NMR studies and crystallographic structures demonstrated that the calix[4]arene derivatives adopted cone conformations. Their cationic binding abilities and selectivities towards heavy and tran- sition metal ions have been evaluated by solvent extraction of aqueous metal picrates. The obtained results indicated that the introduction of nitrogen, sulfur, and/or phosphor atoms to the calix[4]arene framework could effectively enhance their binding ability and selectivity for heavy and transition metal ions, such as Pb2 or Ag .