1,3-偶极环加成合成双-4,5-二氢-1,2,4-噁二唑啉衍生物

用2-苯基-1,2,3-三唑基-4-甲醛(1)或喹喔啉基-2-甲醛(2)与乙二胺缩合成双席夫碱3或4, 然后与α-氯代肟在三乙胺条件下发生1,3-偶极环加成得到双-4,5-二氢-1,2,4-噁二唑啉衍生物6a～6f或7a～7f. 目标化合物的结构经元素分析, IR, ¹H NMR和MS确认.     

Utilization of Dipotassium Salt of Galactaric Acid Bis(Hydrazidocarbodithioic Acid) As a Synthone for Double-Headed 1,3,4-Thiadiazoline, 1,3,4-Oxadiazoline and 1,2,4-Triazoline Acyclo C-Nucleosides

Condensation of galactaric acid bis hydrazide (1) with carbon disulfide in the presence of ethanolic potassium hydroxide gave the dipotassium salt of galactaric acid bis (hydrazidocarbodithioic acid) (2). Heterocyclization of the key compound 2 produced three different types of double headed acyclo C-nucleosides: acid-catalyzed dehydrative cyclization afforded the 5-thioxo-1,3,4-thiadiazoline 3, base-catalyzed dehydrosulfurative cyclization gave the 5-thioxo-1,3,4-oxadiazoline 5, and condensative cyclization with concomitant dehydrosulfuration and dehydration with different nitrogen nucleophiles yielded the 5-thioxo-1,2,4-triazolines 7 and 9a, b. Acetylation of the prepared acyclo C-nucleosides 3, 5, 7 and 9a, b with acetic anhydride in the presence of pyridine at ambient temperature caused acetylation of the sugar hydroxyls as well as heterocyclo imino protons to give the tetra-O-acetates 4, 6, and 10a, b, respectively. Representative members of the prepared compounds were tested for antimicrobial activity.     

Synthesis and Reactions of New Fused Heterocycles Derived from 5-Substituted-4-Amino-3-Mercapto-(4H)-1,2,4-Triazole with Biological Interest

The reaction of thiocarbohydrazide with carboxylic acids at the melting temperature allows an improved preparation of 5-substituted-4-amino-3-mercapto 1,2,4-triazoles 1 _{a ? g} . Compound 1 _a reacted with 2-bromopropionic acid to give acid derivative 2 . The latter was reacted with a mixture of acetic anhydride and triethylamine to afford the mesoionic compound 3 . Heating of compound 3 in ethanol gave the ester derivative 4 , which on alkaline hydrolysis in methanol gave ketone derivative 5 . Substituted 1,2,4-triazolo [3,4-b]-6H-1,3,4-thiadiazine 6 _h,i and 7 were synthesized by reaction of 1 _a with acetylacetone, ethyl acetoacetate and chloroacetamide. Heterocyclic systems 8 and 9 were prepared through the reaction of 1 _a with 2,3-dichloro-1,4-naphthoquinone and 2,3-dichloroquinoxaline. In addition, thenoyl isothiocyanate, thenoyl chloride, 2-thiophenecarbaldehyde, and p-chlorophenyl isocyanate reacted with compound 1 _a to afford 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole ring system 10 , 11 , and urea derivative 12 . 1,2,4-Triazolo[3,4-b]-5H-pyrazole derivatives 14 _j,k were prepared through the reaction of compound 1 _a with 3-chloro-2,4-pentandione and ethyl-2-chloroacetoacetate. Compound 14 _j was treated with hydrazine to afford products 15 , 16 , and 17 depending on the type of hydrazine derivative and reaction conditions. Compound 19 was synthesized by refluxing of compound 14 _j with hydroxylamine hydrochloride to afford the corresponding oxime derivative 18 followed by treatment with thenoyl chloride.     

2-[3-(Trifluoromethyl)phenyl]furo[3,2-b]pyrroles: synthesis and reactions

The synthesis and reactions of methyl 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole-5-carboxylate (1a) are described. Upon reaction with methyl iodide, benzyl chloride, or acetic anhydride, this compound gave N-substituted products 1b-d. By hydrolysis of compounds 1a-c, the corresponding acids 2a-c were formed, or by reaction with hydrazine-hydrate, the corresponding carbohydrazides 3a-c were formed. By heating 2-[3-(trifluoromethyl)phenly]-4H-furo[3,2-b]pyrrole-5-carboxylic acid (2a) in acetic anhydride, 4-acetyl-2-[3-(trifluoromethyl)phenyl]furo[3,2-b]pyrrole (4) was formed. By hydrolysis of 4, 2-[3-(trifluoromethyl)phenyl]-4H-furo[3,2-b]pyrrole (5a) was formed, and reactions with methyl iodide or benzyl chloride gave N-substituted products 5b-c. The reaction of 4 with dimethyl butynedioate gave substituted benzo[b]furan 6. Compound 3a reacted with triethyl orthoesters giving 7a-c, which afforded with phosphorus (V) sulphide the corresponding thiones 8a-c. The thiones 8a-c reacted with hydrazine hydrate to form hydrazine derivatives 9a-c. The reaction of triethyl orthoformiate with compounds 9a-c led to furo[2′,3′: 4,5]pyrrolo[1,2-d][1,2,4]triazolo[3,4-f][1,2,4]triazines 10a-c. Hydrazones 11a-c were formed from 3a-c and 5-[3-(trifluoromethyl)phenyl]furan-2-carboxaldehyde. The effect of microwave irradiation on some condensation reactions was compared with “classical” conditions. The results showed that microwave irradiation shortens the reaction time while affording comparable yields.     

The Synthesis of Some Pyrazolyl- and Thiazolylthienopyridines

2-acetyl-3-amino-4,6-dimethylthieno[2,3-b]pyridine 1 reacted with dimethoxy-tetrahydrofuran in acetic acid and ethyl cyanoacetate in the presence of ammonium acetate or with NaNO₂ in the presence of an AcOH/HCl mixture to produce 2–4. Compound 2 reacted with aromatic aldehydes, semicarbazide hydrochloride, thiosemicarbazide, and phenyl hydrazine or with hydrazine hydrate to give compounds 5a–c and 11a–d, respectively.

Chalcone 5 reacted with hydrazines, hydroxylamine hydrochloride, or thiourea to produce compounds 6–9. Thiosemicarbazone 11b reacted with α -haloester to produce the corresponding thiazolidinone derivatives 12a, b ; also it reacted with ω -bromoacetophenone to give thiazoline derivatives 13a, b .     

1,3-双[3-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑-6-基]丙烷类化合物的合成

戊二酸(1)与3-芳基-4-氨基-5-巯基-1,2,4-三唑(2a～2o)在相转移催化剂四丁基碘化铵和POCl₃作用下, 高收率合成了一系列新的1,2-双[3-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑-6-基]丙烷(3a～3o). 其结构经IR, ¹H NMR, MS和元素分析确证.     

The Synthesis of Triazolothiadiazines and Thiadiazoles From 1,2-Bis-(4-amino-5-mercapto-1,2,4-triazol-3-yl)- Ethanol and Ethane

The reaction of DL-malic and succinic acids with thiocarbohydrazide afforded 1,2-bis[4-amino-5-mercapto-1,2,4-triazol-3-yl]-ethane derivatives 3a and 3b. The reaction of 3a,b with phenacyl bromide and benzoin afforded 1,2-bis-1,2,4-triazolo [3,4-b][1,3,4]thiadiazine derivatives 4 and 5. The carboethoxymethylation of 3a and 3b gave 6a and 6b, respectively, and their reactions with carbon disulfide and benzoylisothiocyanate gave the 1,2-bis-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole 7 and 9, and with p-nitrobenzaldehyde gave a Schiff's base and dihydrothiadiazole 8. The structures were confirmed by using ¹ H and ¹³ C NMR spectra. Selected members of these compounds were screened for antimicrobial activity.     

水溶性稠杂环均三唑并噻二唑体系的合成及生物活性(I): 哌嗪取代衍生物

4-氨基-5-吡啶-4-基-均三唑硫醇(1)在复合催化剂DMAP和TBAB作用下与对卤代苯甲酸经环缩合反应以高收率得到中间体6-(5-氯-3-甲基-1-取代苯基-1H-吡唑-4-基)-3-吡啶-3-基-均三唑并[3,4-b][1,3,4]噻二唑(2a～2c), 接着苯环卤原子与取代哌嗪在聚乙二醇催化作用下发生亲核取代反应得到相应的哌嗪游离碱(3a～3c). 其中, 单取代哌嗪游离碱3a与含功能基的卤代物缩合得到功能基取代的哌嗪衍生物(4a～4g). 这些产生的游离碱与盐酸反应得到相应的水溶性盐酸盐. 所合成新化合物的结构经元素分析和光谱数据表征, 并评价了它们的体外抗菌活性及构效关系.     

3-O-乙酰基熊果酸3-乙酰基-2-[(未)取代苯基]-2,3-二氢-1,3, -噁二唑-5-甲酯的合成及其抗炎活性研究

熊果酸与氯乙酸乙酯反应制得熊果酸乙氧甲酰基甲酯(2), 2与水合肼反应得到熊果酸甲酰肼甲酯(3), 3与羰基化合物反应得到一系列酰腙4a～4g, 再将4a～4g与乙酸酐作用, 环合得到3-O-乙酰基熊果酸3-乙酰基-2-[(未)取代苯基]-2,3-二氢-1,3,4-噁二唑-5-甲酯(5a～5g). 15个新化合物均未见文献报道, 其结构经¹H NMR, IR, MS加以确证, 并进行了药理结果筛选. 结果表明, 部分化合物具有良好的抗炎活性. 其中, 化合物5a (40 mg•kg^－1), 5d (40 mg•kg^－1), 5g (40 mg•kg^－1)与熊果酸相比, 具有更强的疗效.     

Synthesis and Antimicrobial Properties of New Thiosemicarbazide, 1,2,4-Triazole,and 1,3,4-Thiadiazole Derivatives of Sulfanylacetic Acid

Abstract

1,2,4-triazole and 1,3,4-thiadiazole derivatives are still considered a viable lead structure for the synthesis of more efficient antimicrobial agents having a broad spectrum of activity. This study presents the synthesis and antimicrobial evaluation of a new series of substituted 1,2,4-triazole and 1,3,4-thiadiazole derivatives. Reaction of 4-phenyl-5-(pyridin-3-yl)-4H-1,2,4-triazole-3-thione with ethyl bromoacetate yields the corresponding ethyl acetate (1). In the subsequent reaction with 100% hydrazine hydrate, the hydrazide (2) was obtained, which was converted with isothiocyanates to new acyl derivatives of thiosemicarbazide (3a–l). The cyclization of these compounds in alkaline media resulted in the formation of new derivatives of 1,2,4-triazole (4a–i), whereas in acidic media new derivatives of 1,3,4-thiadiazole (5a,b,g) were obtained. All synthesized compounds were screened for their in vitro antimicrobial activities.     

Synthesis of 3,6-bisubstituted phenyl-bi-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole derivatives

2,5-Bihydrazino-1,3,4-thiadiazole (2) was synthesized by condensation of 2,5-bimercapto-1,3,4-thiadiazole (1) with hydrazine hydrate, and compound 2 reacted with acyl chloride to give 2,5-biacylhydrazino-1,3,4-thiadiazole derivatives (3a–3e). Ring closure of compounds 3a–3e was achieved with POCl3 as the cyclization agent giving 3,6-bisubstituted phenyl-bi-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazole derivatives (4a–4e), respectively. The novel compounds were identified by elemental analysis, and by infrared (IR), 1H-nuclear magnetic resonance (NMR), and mass (MS) spectrometry. The mechanism of the cyclization is also discussed. __________ Translated from Organic Chemistry, 2006, 26(12): 1720–1722 [译自: 有机化学]     

Pyrimido[4,5-e](1,2,4)-triazolo[3,4-b](1,3,4)-thiadiazine-7,9(6H8H)-diones

Some 5H-pyrimido[4,5-e](1,2,4)-triazolo[3,4-b](1,3,4)-thiadiazine-7,9-(6H,8H)-diones (4 a–d) have been synthesised by the condensation of 3-alkyl-4-amino-5-mercapto-(1,2,4)-triazoles (1 a–d) with 5-bromobarbituric acid (2a). Similarly some 9a-nitro-5H-pyrimido[4,5-e](1,2,4)-triazolo[3,4-b](1,3,4)-thiadiazine-7,9(8H,9aH)-diones (5 a–d) have been obtained by the condensation of1 a–d with 5-bromo-5-nitrobarbituric acid (2b) and final cyclisation withPPA. The structures have been confirmed by PMR spectra and analytical results.

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Pyrimido[4,5-e](1,2,4)-triazolo[3,4-b](1,3,4)-thiadiazin-7,9(6H,8H)-dione

Zusammenfassung Es wurden einige 5H-pyrimido[4,5-e](1,2,4)-triazolo[3,4-b](1,3,4)-thiadiazin-7,9(6H,8H)-dione (4 a–d) mittels Kondensation von 3-Alkyl-4-amino-5-mercapto-(1,2,4)-triazolen (1 a–d) mit 5-Brombarbitursäure (2 a) dargestellt. Des weiteren wurden einige 9a-Nitro-5H-pyrimido[4,5-e](1,2,4)-triazolo[3,4-b](1,3,4)-thiadiazin-7,9(8H,9aH)-dione (5 a–d) über die Kondensation von1 a–d mit 5-Brom-5-nitrobarbitursäure (2 b) und anschließender Cyclisierung mitPPA synthetisiert. Die angeführten Strukturen wurden mittels PMR-Spektren und analytischen Daten abgesichert.

     

非对称双(均三唑席夫碱)衍生物的合成及抗肿瘤活性

为寻找新结构的水溶性抗癌先导化合物, 采用氨基均三唑硫代苯丙酮(1)与氨基均三唑硫醇(2a～2e)缩合得双均三唑单席夫碱化物3a～3e, 接着依次与氨基氯乙烷和水杨醛进行亲核取代和缩合反应, 分别得到含碱性侧链的单席夫碱4a～4e和非对称双席夫碱5a～5e. 所合成新化合物的结构经元素分析和光谱数据表征, 用甲基四噻唑蓝比色法(MTT)对新化合物进行了对于CHO, HL60和L1210 3种癌细胞株的体外活性试验. 在合成的15个新化合物中, 双席夫碱结构的抗癌活性最强, 其IC₅₀值在20.0 μmol•L^－1以下, 尤其是均三唑环连有双供电子取代基时(如化合物5c), 表现出潜在的活性, 其抗癌活性与上市药物比生群相当, 具有侯选药物研究的价值.     

Synthesis of Substituted 1‐\C\‐Phenyl‐D‐Tetritols and 1‐C‐(1H‐Pyrazol‐4‐yl)‐D‐tetritols by Ring Transformation of 2‐Formylglycals

Abstract

2‐Formylglycals 1a,b reacted with dialkyl 3‐oxoglutarates in the presence of base to furnish the 5‐[(1R,2R(S),3R)‐1,2,4‐tris(benzyloxy)‐3‐hydroxy‐butyl]‐2‐hydroxy‐isophthalic acid dialkyl esters 2a–d. Treatment of 1a,b with hydrazine derivatives afforded the substituted 1,2,4‐tri‐O‐benzyl‐1C‐(1H‐pyrazol‐4‐yl)‐D‐tetritols 5a–d. Deprotection of 5a,b was achieved with Pd/H₂ to yield the 1C‐(1‐methyl‐1H‐pyrazol‐4‐yl)‐D‐tetritols 6a,b.     

Microwave assisted reactions of 2-[3-(Trifluoromethyl)phenyl]-4-R<Superscript>1</Superscript>-furo[3,2-<Emphasis Type="Italic">b</Emphasis>] pyrrole-5-carboxhydrazides

The effect of microwave irradiation on the reactions of 2-[3-(trifluoromethyl)phenyl]-4-R¹-furo[3,2-b]pyrrole-5-carboxhydrazides 1 with 5-arylfuran-2-carboxaldehydes 2, thiophene-2-carboxaldehyde (3) and methyl 2-formylfuro[3,2-b]pyrrole-5-carboxylates 4 has been studied. Reactions of 1 with formic and acetic acid, respectively, led to acylhydrazides 9a–c. Reaction of 1a with 4-substituted 1,3-oxazol-5(4H)-one 10 led to imidazole derivative 13. 1,2,4-Triazole-3-thiones 15a,b were synthesized by two-step reaction of 1a with potassium isothiocyanate and phenyl isothiocyanate, respectively, and subsequent base-catalyzed cyclization of thiosemicarbazides 14a,b. Pyrazole 16 was prepared by reaction of 1a with pentane-2,4-dione.      

2-取代硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑类化合物的合成、结构与体外抗癌活性

以天然产物没食子酸为原料经醚化、酯化、酰肼化、成盐、闭环、硫醚化六步反应合成了6个2-取代硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑类衍生物, 釆用铟催化下水相合成目标化合物8, 具有反应条件温和, 合成收率高的特点; 用IR, ¹H NMR, ¹³C NMR和元素分析对各化合物进行了表征及结构确证, 并用X射线单晶衍射法测定了化合物8a [2-(2-氯-5-吡啶甲基)硫醚-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑]的晶体结构, 采用MTT法进行了新化合物抑制PC3和BGC-823癌细胞体外试验, 结果表明在5μmol•L^－1浓度下化合物8e对PC3的抑制活性为55.71%. 化合物8b对BGC-823细胞抑制活性为66.21%.     

Synthesis and Antimicrobial Activities of Some 6-Methyl-3-Thioxo-2,3-Dihydro-1,2,4-Triazine Derivatives

Abstract

4-Arylidene-imidazole derivatives (4a,b) were readily prepared by reacting 4-am- ino-6-methyl-3–thioxo-2,3–dihydro[1,2,4]triazin-5(4H)-one (1) with 4-arylidene-2-phenyl- 4H-oxazol-5-one (2). Reaction of 1 with some aromatic aldehydes in presence of triethylphosphite exclusively afforded the corresponding aminophosphonates 5a-c. Reaction of 1 with 3-phenyl-1H-quinazoline-2,4-dione (6a) and/or 3-phenyl-2-thioxo-2,3-dihydro- 1H-quinazolin-4-one (6b) gave 2-(6-methyl-5-oxo-3-thioxo-2,5-dihydro-3H-[1,2,4]triazin-4-ylimino)-3-phenyl-2,3-dihydro-1H-quinazolin-4-one (7). Moreover, on treating 1 with 2-phenylbenzo[d][1,3]thiazine-4-thione (8), 6-methyl-4-(2-phenyl-4-thioxo-4H-quinazolin-3-yl)-3-thioxo-3,4-dihydro-2H-[1,2,4]triazine-5-one (9) was obtained in 65% yield. Reaction of 1 with 4-sulfonylaminoacetic acid derivatives (10a,b) afforded the corresponding sulfonamides (11a,b), respectively. Acid hydrolysis of 11a afforded 7-aminomethyl-3-methyl[1,3,4]thiadiazole[2,3-c][1,2,4]triazin-4-one (12). 4-Amino-6-methyl-3-(morpholine-4-ylsulfanyl)-4H-[1,2,4]triazin-5-one (14) was prepared by reacting compound 1 with morpholine in presence of KI/I₂, while 3,3′-bis(4-amino-6-methyl-5-oxo-triazinyl)disulfide (16) was obtained by oxidation of 1 with lead tetraacetate. The antimicrobial activity of the products was evaluated against Gram-positive and Gram-negative bacteria as well as the fungus Candida albicans.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text, figures, and tables.]     

3-Methyl[1,3,4]thiadiazino[2,3-b]quinazolin-6-ones

4H,6H-[1,3,4]Thiadiazino[2,3-b]quinazolin-6-one with a methyl group in position 3 (6a) has been synthesised by the condensation of 3-amino-2-mercapto-3H-quinazolin-4-one (1) with allyl bromide (2) followed by treatment with bromine and subsequent dehydrohalogenation of the brominated product (4) with ethanolic sodium hydroxide. Its isomeric 3-methyl-2H,6H-[1,3,4]thiadiazino[2,3-b]quinazolin-6-one (6b) has also been obtained by condensation of1 and bromoacetone (7) followed by cyclisation of the intermediates (8 or9) with hydrobromic acid or with concentrated sulphuric acid. The structures have been established on the basis of IR and PMR data.

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3-Methyl[1,3,4]thiadiazino[2,3-b]chinazolin-6-one

Zusammenfassung Zur Synthese von 4H,6H-[1,3,4]thiadiazino[2,3-b]chinazolin-6-on (6a) wurde die Kondensation von 3-Amino-2-mercapto-3H-chinazolin-4-on (1) mit Allylbromid mit nachfolgender Behandlung mit Brom und Dehydrohalogenierung des bromierten Produktes4 mit ethanolischer Natronlauge herangezogen. Das zu6a isomere 2H,6H-Produkt6b wurde ebenfalls durch Kondensation von1 mit Bromaceton und nachfolgender Cyclisierung der Zwischenprodukte8 bzw.9 mit HBr oder H₂SO₄ erhalten. Die Strukturen wurden mittels IR und NMR abgesichert.

     

微波辅助合成双1,2,4-三嗪化合物及其荧光特性研究

以联苯甲酰、二甲酰肼为原料, 采用微波技术合成了5个双1,2,4-三嗪化合物3, 产率72%～85%, 利用元素分析、MS, IR, ¹H NMR和荧光光谱对其结构进行了表征, 并研究了金属离子对化合物3a的荧光性质的影响. 结果表明, 微波合成具有缩短反应时间、提高产率的优点; Cu^2＋, Ni^2＋等金属离子对化合物3a产生明显的荧光猝灭作用.     

Preparation and Characterisation of a Bis-μ-Hydroxo-NiIII2 Complex

Hydroxide-bridged high-valent oxidants have been implicated as the active oxidants in methane monooxygenases and other oxidases that employ bimetallic clusters in their active site. To understand the properties of such species, bis-μ-hydroxo-Ni^II₂ complex ( 1 ) supported by a new dicarboxamidate ligand (N,N′-bis(2,6-dimethyl-phenyl)-2,2-dimethylmalonamide) was prepared. Complex 1 contained a diamond core made up of two Ni^II ions and two bridging hydroxide ligands. Titration of the 1 e⁻ oxidant (NH₄)₂[Ce^IV(NO₃)₆] with 1 at −45 °C showed the formation of the high-valent species 2 and 3 , containing Ni^IINi^III and Ni^III₂ diamond cores, respectively, maintaining the bis-μ-hydroxide core. Both complexes were characterised using electron paramagnetic resonance, X-ray absorption, and electronic absorption spectroscopies. Density functional theory computations supported the spectroscopic assignments. Oxidation reactivity studies showed that bis-μ-hydroxide-Ni^III₂ 3 was capable of oxidizing substrates at −45 °C at rates greater than that of the most reactive bis-μ-oxo-Ni^III complexes reported to date.