Syntheses and properties of new herbicidal 2-arylthio-1 ,2,4-triazolo[1,5-a] pyrimidine derivatives

In search of novel herbicides with high activity, a series of 2-arylthio-1,2,4- triazolo [1, 5-a ] pyrimidines (3) were synthesized by cyclization of 5-amino-3-arylthio-1,2,4-triazoles with 1,3-diketones or by the nucleophilic substitution of substituted thiophenols with 2-methylsulfonyl-1, 2, 4-triazolo [ 1, 5-a]-pyrimidine. The structures of all compounds prepared were confirmed by 1H NMR and MS spectroscopy along with elemental analyses. Preliminary bioassays indicated that some of the compounds 3 had good herbicidal activity against rape. In addition, the regioselectivity in the reaction of 5-amino-3-sub-stituted arylthio-1,2,4-triazoles with benzoylacetone was studied.     

含肟醚的新型三唑并嘧啶衍生物的合成及除草活性研究

2-巯基-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶(6)与氯乙醛或氯丙酮反应生成5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶-2-硫丙酮(硫乙醛) (7). 中间体7与O-烷基(芳基)羟胺(5)反应得到目标化合物1-(5,7-二甲基-1,2,4三唑[1,5-a]嘧啶-2-硫)乙醛-O-烷基肟醚(9), 2-(5,7-二甲基-1,2,4三唑[1,5-a]嘧啶-2-硫)丙酮O-烷基肟醚(10). 初步生物活性测试结果表明部分化合物具有较好的除草活性.     

三唑并嘧啶双杂环硫醚衍生物的合成与生物活性

以2-巯基-5, 7-二甲基-1, 2, 4-三唑并[1, 5-a]嘧啶为原料,设计合成了10种含5, 7-二甲基-1, 2, 4-三唑并[1, 5-a]嘧啶环和1, 2, 4-三唑环的双杂环硫醚化合物,结构经MS、1H NMR进行表征。初步的生物活性测试表明,在50×10-6 g/L浓度下,大部分化合物6对甜菜褐斑病菌表现出好的抑制效果, 化合物6b、6e、6f、6g、6h抑制效果达到A级（≥90%）。     

5,7-二取代-2-(2,4-二氯苯氧乙酰亚胺基)-2H-1,2,4-噻二唑并[2,3-a]嘧啶衍生物的合成、晶体结构及除草活性

设计并合成了 5种 5 ,7 二取代 2 ( 2 ,4 二氯苯氧乙酰亚胺基 ) 2H 1,2 ,4 噻二唑并 [2 ,3 a]嘧啶类化合物 5 ,均为未见文献报道的新化合物 .利用1HNMR、元素分析等确定了产物的结构 .初步除草活性测定结果表明 ,化合物 5对阔叶植物有优良的除草活性 ,且有一定的选择性 .为了进一步了解该类化合物的结构 ,也为设计新的除草剂分子提供帮助 ,对其中一种化合物 5b进行了X射线单晶衍射     

Synthesis,Antibacterial, and Antifungal Activities of Imidazo[2,1-c][1,2,4]triazoles and 1,2,4-Triazolo[4,3-a]pyrimidinones

A straightforward method has been developed for the synthesis of 1-phenyl-imidazo [2,1-c][1,2,4]triazole derivatives 5a–j and 1-phenyl-[1,2,4]triazolo[4,3-a]pyrimidinones derivatives 6a–g starting from 5-amino-1-phenyl[1,2,4]triazole and p-toluenesulfonic acid (PTSA). This methodology affords a number of 1-phenyl-imidazo [2,1-c][1,2,4]triazoles 5a–j and 1-phenyl-[1,2,4]triazolo[4,3-a]pyrimidinones 6a–g in reasonable yields and short reaction times. The structures of all new compounds were elucidated using infrared, ¹H and ¹³C NMR, and high-resolution mass spectrometry. Some of the newly synthesized compounds were screened for their antimicrobial activity.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications ^® for the following free supplemental resource(s): Full experimental and spectral details.]     

Synthesis of 5,7-Dimethyl-2-(5-Substituted-1,3,4-Oxadiazole-2-yl)- Methylenethio-1,2,4-Triazolo[1,5-a]Pyrimidines as Potential Fungicides

New challenging problems in plant protection technology have promoted research to discover more efficient pesticides. In recent years, many chemists have paid much attention to compounds bearing 1,2,4-triazolo [1,5-a] pyrimidine rings due to their broad spectrum of biological activities such as herbicidal and fungicidal effects1-7. Up to now, a great variety of these kinds of compounds have been synthesized, among which some commercially herbicides have been developed including metosulam, f…     

含噁二唑杂环取代的新型三唑并嘧啶衍生物的合成及其生物活性

2-肼羰基亚甲硫基-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶与二硫化碳在乙醇溶液中回流制得化合物2-(5-巯基-1,3,4-噁二唑-2-亚甲硫基)-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶, 后者在碱性环境中与卤化苄反应得到17种新型双杂环化合物. 对所得化合物结构均经元素分析, ¹H NMR和MS确认. 初步生物活性测试表明这些化合物具有一定的杀菌活性.     

Synthesis of New 4,5-Dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-amine–Derived Ureas and Their Anticancer Activity

A new series of 1,2,4-triazolo[4,3-a]-quinoline derivatives were designed and synthesized to meet the structural requirements essential for anticancer activity. N-1-(5-Methylisoxazol-4-yl/4-fluoro-2,3-dihydro-1H-inden-1-yl/aryl)-N’-3-(4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-yl) urea derivatives were accomplished in good yields by the reaction of 4,5-dihydro-1-methyl-[1,2,4]triazolo[4,3-a]quinolin-7-amine with 3-(3-chloro-5-fluoro-2-methoxyphenyl)-5-methyl-isoxazole-4-carboxylic acid, 4-fluoro-2,3-dihydro-1H-indene-1-carboxylic acid, and various simple aromatic carboxylic acids in the presence of diphenyl phosphoryl azide (DPPA). All the newly synthesized title compounds were characterized by elemental and spectral data. Furthermore, anticancer activity was screened for the title compounds (12a–j) in vitro against human neuroblastoma cell lines (SK N SH) and human colon carcinoma cell lines (COLO 205) by using the MTT cell viability method. A few of them (12a and 12b) possess significant cytotoxicity, and some other compounds 12d-f and 12j displayed moderate cytotoxicity against both cell lines.     

咪唑[1,5-a]吡啶鎓盐的合成、表征及生物活性测定

通过三组份串联反应合成一系列咪唑[1,5-a]吡啶鎓盐,利用1H NMR、13C NMR、MS以及X射线单晶衍射确定其结构,其中以二乙烯三胺与三乙烯四胺为原料获得预期外的结构。以青霉素作为对照,研究了化合物的抗菌性。结果表明,所合成的化合物对溶壁微球菌和乙型链球菌均有抗菌效果,化合物2的抗菌效果最好;含有杂原子O的化合物3对嗜麦芽单胞菌和肺炎克雷伯氏菌的抗菌能力优于青霉素;联苯桥联的刚性双齿咪唑[1,5-a]吡啶鎓(5)比乙基桥联的柔性双齿咪唑[1,5-a]吡啶鎓(4)的抗菌性更强;化合物6为单齿大π体系芳香环,其抗菌效果较好,而化合物7和8为双齿的大π体系芳香环,其抗菌效果较弱。     

Condensed thienopyrimidines. I. Synthesis and gastric antisecretory activity of 2,3-dihydro-5H-oxazolothienopyrimidin-5-one derivatives

A practical preparation of various 2,3-dihydro-5H-oxazolo[3,2-a]thieno[3,2-d]-, [3,4-d]-, and [2,3-d]pyrimidin-5-one derivatives was developed starting from the corresponding aminothiopheneesters in two steps, and their chloro-substituted derivatives were prepared. These compounds were evaluated for gastric antisecretory activity in pylorus-ligated rats, compared to the anti-ulcer standard, cimetidine, and their structure-activity relationships are discussed.     

Mass spectra of tetrahydroisoquinoline-fused 1,3,2-O,N,P- and 1,2,3-O,S,N-heterocycles: influence of ring size and fusion, of present heteroatoms, substituent effects and of the stereochemistry on fragmentation

The electron ionization (EI) mass spectra of a variety of stereoisomeric tricyclic 1,3,2-oxazaphosphino[4,3-a]isoquinolines (1-4), 1,2,3-oxathiazino[4,3-a]isoquinoline-4-oxides (5-7) and the -4,4-dioxides (8-10) of oxazaphospholo- and oxathiazolo[4,3-a]- (11, 12, 15 and 16) and -[3,4-b]isoquinolines (13, 14 and 17) were recorded. Ring size and fusion, the different heteroatoms (P and S) and substituents on the ring systems strongly influence the mass spectra. In addition, mass spectra of the stereoisomers of compounds 1, 2 and 13, 14 revealed stereochemically relevant differences which are not observed for the other pairs of isomers.     

Crowned Macrocycles Containing Two Pyrrolo[1,2-a] Indoles Created By Intramolecular Fusion

Heterocyclic fused-ring systems are of utmost importance because of their presence in many natural products with biological activity. Pyrroloindoles are tricyclic heterocycles that are present in various bioactive and medicinally valuable compounds. Herein, we report the synthesis of phenylene-bridged bis-pyrrolo[1,2-a]indole crowned macrocycles 1 – 3 in which the pyrrolo[1,2-a]indole moieties were formed via intramolecular fusion. The macrocycles were thoroughly characterized by 1D and 2D NMR, HRMS and X-ray crystallographic studies. The X-ray structure revealed that the two pyrrolo[1,2-a]indole moieties were parallel to each other, and one pyrrolo[1,2-a]indole unit was deviated by an angle of 9.54° while the other pyrrolo[1,2-a]indole unit was deviated by an angle of 12.0° from the mean plane defined by 28 core atoms. The macrocycles 1 – 3 absorb in the visible region and readily undergo oxidations because of their electron rich nature. The macrocycles 1 – 3 upon treatment with trifluoroacetic acid (TFA) generates the corresponding cation radicals 1 – 3 ^.+ which were stable in the open air for a week. The cation radicals 1 – 3 ^.+ absorb strongly in the NIR region and the experimental observations on crowned macrocycles 1 – 3 were corroborated by DFT and TD-DFT studies.     

5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶-2-硫乙酰腙类 衍生物的合成及生物活性 研究

以2-巯基-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶为起始原料,设计合成了16种新型的-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶-2-硫乙酰腙类衍生物,其结构均经1^HNMR,MS及元素分析确证。通过核磁共振氢谱分析及分子力学优化,对该类化合物在溶液中的顺反异构体的化学位移进行了归属。初步生测结果表明,所合成的化合物均表现出不同程度的除草及杀菌活性,尤其是在50×^-6浓度下所有化合物都对水稻纹枯病表现出很好的抑制效果。对化合物4c和4o活体小株实验结果表明,在先接菌后施药的处理方式下,化合物在50×^-6和100×^-6浓度下对水稻纹枯病的防效均优于多菌灵和井冈霉素,在100×^-6浓度下的防效达到了80%以上。     

Synthesis,spectral characterization,and antituberculosis activity of thiazino[3,2-A]benzimidazole derivatives

A series of novel thiazino[3,2-a]benzimidazole derivatives synthesized by cyclization of (R)-2-(chloromethyl)oxirane with benzimidazole-2-thiol followed by reacted with benzyl bromides in high yield under milder conditions. The molecular structures of all compounds were confirmed by ¹H and ¹³C NMR spectroscopy and Mass spectrometry. The absolute configuration of the compounds was confirmed by X-ray diffraction analysis. All the synthesized compounds were evaluated in vitro for their antituberculosis activity.     

A novel heterocyclic compound. Synthesis and reactivities of an oxazolo[3,2-a]thieno[3,2-d]-pyrimidine derivative

A practical preparation of 2,3-dihydro-5H-oxazolo[3,2-a]thieno[3,2-d]pyrimidin-5-one (2) from methyl 3-aminothiophene-2-carboxylate in two steps was developed. The addition reactions of various nucleophiles to 2 were investigated and oxazole-ring-opened compounds were produced (5, 6, 12, 13 and 14). Desulfurization reaction of 2 with Raney Ni gave an oxazolo[3,2-a]pyrimidine derivative (15). It was found that 2 showed potent anti-gastric secretion activity.     

5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶双杂环衍生物的合成与生物活性

以2-巯基-5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶为原料, 设计合成了17种含5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶环和1,2,4-三唑环的新型双杂环化合物, 结构经元素分析, MS, 1H NMR及13C NMR进行表征. 初步的生物活性测试表明, 部分化合物表现出较好的杀菌、除草活性.     

4-Hydroxy-2-quinolones. 180*. Synthesis,chemical reactions,and analgesic activity of 1-allyl-4-hydroxy-6,7-dimethoxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid alkylamides

A targeted synthesis was carried out of a series of 1-allyl-4-hydroxy-6,7-dimethoxy-2-oxo-1,2-di-hydroquinoline-3-carboxylic acid alkylamides which show interest for biological study as potential analgesics. It was found that, in the presence of one equivalent of bromine, the compounds indicated undergo halocyclization to the corresponding 2-bromomethyl-7,8-dimethoxy-5-oxo-1,2-dihydro-5H-oxa-zolo[3,2-a]quinoline-4-carboxylic acid alkylamides. However, with an excess of bromine the reaction occurs somewhat differently and concludes with the formation of complexes of bromine with 4-alkyl-carbamoyl-2-bromomethyl-5-hydroxy-7,8-dimethoxy-1,2-dihydrooxazolo[3,2-a]quinolinium ditri- bromides. According to the results of pharmacological screening there are found compounds within the substances discovered with high analgesic activity.     

5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶-2-甲酰腙类化合物的合成与生物活性

以5-氨基-1H-1,2,4-三唑-3-羧酸为起始原料, 设计合成了13个新型的5,7-二甲基-1,2,4-三唑并[1,5-a]嘧啶-2-甲酰腙类化合物, 通过¹H NMR, MS和元素分析对所合成的化合物进行了结构表征. 初步的生物活性测试结果表明, 所合成的化合物均表现出不同程度的除草及杀菌活性, 其中化合物4b, 4h和5m的活性较好, 在50 mg/L浓度下对水稻纹枯病菌的抑制率达90 %以上.     

Synthesis of 3-Substituted Pyrido[4′,3′:4,5]thieno[2,3-d]pyrimidines and Related Fused Thiazolo Derivatives

New ethyl 3-(substituted)-4-oxo-2-thioxo-1,2,3,4,5,6,7,8-octahydropyrido[4',3':4,5]thieno-[2,3-d]pyrimidine-7-carboxylates ( 3a , b ), ( 6 ),( 11-13 ), ethyl 3-methyl-5-oxo-2,3,6,9-tetrahydro 5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]pyrimidine-8(7H)-carboxylate ( 4 ), and ethyl 2-methyl-5-oxo-2,3,6,9-tetrahydro-5 H -pyrido[4',3':4,5]thieno[2,3-d][1,3]thiazolo[3,2-a]-pyrimidine-8(7H)-carboxylate ( 8 ) have been synthesized from diethyl 2-isothiocyanato-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3,6-dicarboxylate 1. The structure of these compounds as well as their intermediates have been established by their spectral data.