Synthesis and antitumor activity of novel pyridazinone derivatives containing 1,3,4-thiadiazole moiety

Abstract

A series of novel pyridazinone derivatives containing the 1,3,4-thiadiazole moiety were synthesized and characterized by ¹H NMR, 13C NMR, spectroscopies HRMS and IR. Among them, the structure of compound 5c (2-(Tert-butyl)?4-chloro-5-((5-((2-ethylphenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One) was unambiguously confirmed via single crystal X-ray diffraction analysis. The inhibitory activity of all the target compounds against MGC-803 and Bcap-37 was determined by MTT assay, with doxorubicin (the inhibition rates were 95.5?±?0.4% and 95.7?±?1.0% respectively) as a control. The preliminary results showed that the inhibitory activity of compound 5n (2-(Tert-butyl)?4-chloro-5-((5-((3-fluorophenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One) was superior to the others. The inhibition rates of MGC-803 and Bcap-37 cells were 86.3?±?2.2% and 92.3?±?0.6% at a concentration of 10?μmol/L, respectively. The preliminary structure-activity relationship showed that when the 2-position of the benzene ring was substituted by a methyl group, such as compound 5j (2-(Tert-butyl)?4-chloro-5-((5-((2,3-dimethylphenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One), it exhibited good anticancer activity on MGC-803 cells. Besides, introducing fluorine, chlorine, or trifluoromethyl group onto the benzene ring, such as compound 5?m (2-(Tert-butyl)?4-chloro-5-((5-((4-(trifluoromethoxy)phenyl)amino)?1,3,4-thiadiazol-2-yl)thio)pyridazin-3(2H)-One), displayed good anticancer activity on MGC-803 and Bcap-37 cells.     

A simple and efficient approach for the synthesis of a novel class aliphatic 1,3,4-thiadiazol-2(3H)-one derivatives via intramolecular nucleophilic substitution reaction

In this study, we synthesized a new series of substituted aliphatic 1,3,4-thiadiazol-2(3H)-one derivatives (6-24) in yields ranging from 42 to 70% with an interesting mechanism that involves internal nucleophilic substitution followed by an S_N2-type nucleophilic substitution. First, 1-(4-chlorophenyl)-2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethanone (3) was synthesized from the reaction of 5-methyl-1,3,4-thiadiazole-2-thiol (1) with 2-bromo-1-(4-chlorophenyl)ethanone (2) in the presence of potassium hydroxide. Then, 1-(4-chlorophenyl)-2-((5-methyl-1,3,4-thiadiazol-2-yl)thio)ethanol (4) was synthesized by a reduction reaction of this compound using NaBH₄. Finally, 5-methyl-3-alkyl-1,3,4-thiadiazol-2(3H)-one derivatives (6-24), which are the target compounds, were synthesized from the reaction of this compound (4), which is a secondary alcohol with various alkyl halides (5a-n) in the presence of sodium hydride (NaH). This study presents an interesting reaction mechanism related to the synthesis of aliphatic 1,3,4-thiadiazol-2(3H)-one derivatives that is not recorded in the literature.     

新型含哌嗪1,3,4-噻二唑酰胺衍生物的合成及其生物活性

以氨基硫脲和二硫化碳为起始原料,合成了15个新型的1,3,4-噻二唑衍生物(6a~6o),其结构经¹H NMR,¹³C NMR,IR,ESI-MS和元素分析表征。生物活性测试结果表明：大部分化合物对水稻白叶枯细菌有良好的抑制活性,其中,N-［5-(2,4-二氯苄基)硫醚］-1,3,4-噻二唑-2-(2-N-甲基哌嗪)-乙酰胺(6b)和N-［5-(4-三氟甲氧基苄基)硫醚］-1,3,4-噻二唑-2-(2-N-甲基哌嗪)-乙酰胺(6e)的EC₅₀分别为17.5 μg·mL^-1和19.8 μg·mL^-1; N-[5-(3-甲基苄基)硫醚)-1,3,4-噻二唑-2-(2-哌嗪)-乙酰胺(6k)在浓度为500 μg·mL^-1时,对烟草花叶病毒有一定的抑制活性。     

Synthesis and Evaluation of Polyfunctionally Substituted Heterocyclic Compounds Derived from 2-Cyano-N-(5-pentadecyl-1,3,4-thiadiazol-2-yl)acetamide

Reaction of 5-pentadecyl-1,3,4-thiadiazol-2-amine 2 with ethyl cyanoacetate gave 2-cyano-N-(5-pentadecyl-1,3,4-thiadiazol-2-yl)acetamide 3, which was used to synthesize different heterocyclic derivatives with coumarin, pyrazole, thiazole, pyridine, pyrimidine, and thiophene rings. Propoxylation of these compounds by using 5 mol of propylene oxide produced nonionic surface active agents. Antimicrobial and surface activities were evaluated.     

Synthesis and Antimicrobial Activity of 2-Substituted-3-((3-(6-Nitrobenzo[D]thiazol-2-yl)-4-oxo-3,4-Dihydroquinazolin-2-yl)Methyl)-1,3,4-thiadiazol-3-ium-5-thiolate

Abstract

A new series of 2-substituted-3-((3-(6-nitrobenzo[d]thiazol-2-yl)-4-oxo-3,4-dihydroquinazolin-2-yl)methyl)-1,3,4-thiadiazol-3-ium-5-thiolate 6(a–j) was synthesized starting from anthranilic acid 1. The structures of the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, mass spectra, and elemental analysis. The final compounds were tested for their antimicrobial activity against several microbes.

[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 and tables.]     

Synthesis and biological evaluation of 5-methyl-4-phenyl thiazole derivatives as anticancer agents

Abstract

New N-(5-methyl-4-phenylthiazol-2-yl)-2-(substituted thio)acetamides were synthesized and studied for their anticancer activity. The title compounds were procured by reacting 2-chloro-N-(5-methyl-4-phenylthiazol-2-yl)acetamide with some mercapto derivatives. The structural elucidation of the compounds was performed by ¹H-NMR, ¹³C-NMR and LC-MS/MS spectral data and elemental analyses. The synthesized compounds were investigated for their antitumor activities against A549 human lung adenocarcinoma cells and NIH/3T3 mouse embryoblast cell line for determining their selective cytotoxicity. 2-[(1-methyl-1H-tetrazol-5-yl)thio]-N-(5-methyl-4-phenylthiazol-2-yl)acetamide (4c) showed high selectivity, and whose IC₅₀ value was determined as 23.30?±?0.35?µM and >1000?µM against A549 human lung adenocarcinoma cells and NIH/3T3 mouse embryoblast cell lines, respectively. 2-[(1-Methyl-1H-imidazol-2-yl)thio]-N-(5-methyl-4-phenyl thiazol-2-yl)acetamide (4a) and 2-[(1-Methyl-1H-tetrazol-5-yl)thio]-N-(5-methyl-4-phenyl thiazol-2-yl)acetamide (4c) exhibited the highest apoptosis percentage among those tested, but not as high as the standard, cisplatin.     

Synthesis and nematicidal activities of 1,2,3-benzotriazin-4-one containing 4,5-dihydrothiazole-2-thiol derivatives against Meloidogyne incognita

Abstract

A series of novel 1,2,3-benzotriazin-4-one derivatives containing 4,5-dihydrothiazole-2-thiol were synthesized and characterized by ¹H NMR, ¹³C NMR, ¹⁹F NMR and HRMS. The bioassay results showed that compounds 3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)-7-methoxybenzo[d][1–3]triazin-4(3H)-one, 3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)-6-nitrobenzo[d][1–3]triazin-4(3H)-one, 7-chloro-3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)benzo[d][1–3]triazin-4(3H)-one exhibited good control efficacy against the cucumber root-knot nematode disease caused by Meloidogyne incognita at the concentration of 10.0?mg L^?1 in vivo. Compound 7-chloro-3-(3-((4,5-dihydrothiazol-2-yl)thio)propyl)benzo[d][1–3]triazin-4(3H)-one showed excellent nematicidal activity with inhibition 68.3% at a concentration of 1.0?mg L^?1. It suggested that the structure of 1,2,3-benzotriazin-4-one containing 4,5-dihydro-thiazole-2-thiol could be optimized further.     

α-(1,3,4-噻二唑-5-基)氨基烃基膦酸酯的合成及生物活性

以5-氨基-2-巯基的席夫碱与亚磷酸二乙酯反应, 合成了15个新的α-(1,3,4-噻二唑-5-基)氨基烃基膦酸酯, 初步的生物活性测试表明部分目标化合物具有较好的植物生长调节活性, 其中2,4-二氯苯甲醛、呋喃甲醛和吲哚甲醛的席夫碱生成的α-氨基烃基膦酸酯具有较好的生长素活性.     

Synthesis and characterization of mono- and bicyclic heterocyclic derivatives containing 1,2,4-triazole, 1,3,4-thia-, and -oxadiazole rings

A series of new N- and S-substituted 1,3,4-oxadiazole derivatives were synthesized. 5-Pyridin-3-yl-3-[2-(5-thioxo-4,5-dihydro-l,3,4-thiadiazol-2-yl)ethyl]-1,3,4-oxadiazole-2(3H)-thione and 5-[(5-(pyridin-3-yl)-1,3,4-oxadiazol-2-ylthio)methyl]-N-phenyl-1,3,4-thiadiazol-2-amine were formed by cyclization of 3-(5-pyridin-3-yl-2-thioxo-1,3,4-oxadiazol-3(2H)-ylpropanimidohydrazide and 2-[(5-pyridin-3-yl-1,3,4-oxadiazol-2-yl)thio]thiosemicarbazide with CS₂ and H₂SO₄. On the other hand, a number of new bicyclic 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole derivatives were synthesized. 6-Pyridin-3-ylbis[1,2,4]‐triazolo[3,4-b:4′,3′-d][1,3,4]thiadiazole-3(2H)-thione was synthesized by reaction of 6-(hydrazino)-3-pyridine-3-yl[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole with CS₂/KOH/EtOH. The structures of the newly synthesized compounds were elucidated by the spectral and analytical data IR, Mass, and ¹H NMR spectra. Correspondence: Adel A.-H. Abdel-Rahman, Department of Chemistry, Faculty of Science, Menoufia University, Shebin El-Koam, Egypt; Wael A. El-Sayed, National Research Centre, Department of Photochemistry, Cairo, Egypt.     

Novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties: Design,synthesis, and insecticidal activity

Abstract

A series of novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties were designed, synthesized, and evaluated for their insecticidal activity. Bioassays indicated that some of the target compounds exhibited good insecticidal activities against Plutella xylostella (P. xylostella), Vegetable aphids (V. aphids), and Empoasca vitis (E. vitis). In particular, compound (E)-2-((5-(2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropyl)-1,3,4-oxadiazol-2-yl)thio)-N'-(4-(trifluoromethyl)benzylidene)acetohydrazide (6s) revealed excellent insecticidal activities against P. xylostella, V. aphids, and E. vitis with the 50% lethal concentration (LC₅₀) values of 5.23, 7.07, and 1.61?mg/L, respectively, which were similar to or even better than those of chlorpyrifos, beta cypermethrin, spinosad, and azadirachtin. These results indicated that novel pyrethrin derivatives containing hydrazone and 1,3,4-oxadiazole thioether moieties could be developed as novel and promising insecticides.     

Synthesis of novel azabicyclo derivatives containing a thiazole moiety and their biological activity against pine-wood nematodes

Abstract

To explore a new skeleton with nematicidal activity, a series of novel azabicyclo derivatives containing a thiazole moiety were designed, synthesized and evaluated for their nematicidal activities. The bioassay results against pine-wood nematodes (Bursaphelenchus xylophilus) showed that most of the title compounds displayed nematicidal activity at a concentration of 40?mg/L. Especially, the title compounds2-((8-methyl-8-azabicyclo[3.2.1]octan-3-yl)oxy)-4-(4-chlorophenyl)thiazole (7e), 2-((8-methyl-8-azabicyclo[3.2.1]octan-3-yl)thio)-4-phenylthiazole (10a) and 2-((8-methyl-8-azabicyclo [3.2.1]octan-3-yl)thio)-4-(4-chlorophenyl)thiazole (10e) exhibited more than 90% mortality against Bursaphelenchus xylophilus.     

Synthesis of some novel 3,4,5-trisubstituted triazole derivatives bearing quinoline ring and evaluation of their antimicrobial activity

Abstract

Some new 3,4,5-trisubstituted 1,2,4-triazole derivatives were synthesized and studied for their antimicrobial activity. The lead compounds were obtained starting from 8-hydroxyquinoline and ethyl 2-chloroacetate. The obtained ester compound (1) first reacted with hydrazine hydrate (2) then with phenyl isothiocyanate (3). Ring closure by KOH led to 3-mercapto-1,2,4-triazole derivative (4). Lastly, it reacted with 2-chloro-N-(substituted (benzo)/thiazole)acetamide derivatives to obtain the final compounds (5a–j). The structural elucidation of the compounds was performed by ¹H NMR and ¹³C NMR spectroscopy and high resolution mass spectrometry techniques and elemental analysis. The synthesized compounds were investigated for their antimicrobial activities against seven bacteria and four fungi. As a result of the activity studies, it was observed that compounds N-(6-nitrobenzothiazol-2-yl)-2-[[4-phenyl-5-((quinolin-8-yloxy)methyl)-4H-1,2,4-triazol-3-yl]thio]acetamide (5a) and N-(6-fluorobenzothiazol-2-yl)-2-[[4-phenyl-5-((quinolin-8-yloxy)methyl)-4H-1,2,4-triazol-3-yl]thio]acetamide (5d) were the most active molecules. Also, the antifungal activity of the compounds was found to be higher than their antibacterial activity although lower than the standard drug’s potential. Additionally, the physicochemical properties of the compounds were calculated which were evaluated to be at a suitable range for oral administration.     

含吡啶环的N-(1,3,4-噻二唑-2-基)苯甲酰胺类化合物的合成及其抑菌活性

以3-吡啶乙酸盐酸盐与氨基硫脲为原料经环化反应制备中间体2-氨基-5-(3-吡啶亚甲基)-1,3,4-噻二唑,后者与取代苯甲酰氯反应合成了一系列含吡啶环的N-(1,3,4-噻二唑-2-基)取代苯甲酰胺(3a~3k),其结构通过IR、~1H NMR、~(13)C NMR、MS和元素分析确证。用菌丝生长速率法测定了目标化合物对灰霉菌的离体抑菌活性,结果表明,部分化合物对病原菌有一定的抑制活性。     

Synthesis and monoamine oxidase A/B inhibitory evaluation of new benzothiazole-thiazolylhydrazine derivatives

Abstract

In this study, a novel series of benzothiazole-thiazolylhydrazine (3a–3i) was synthesized and their structures were characterized by ¹H-NMR, ¹³C-NMR spectrometry, and mass spectroscopy. These compounds were evaluated as inhibitors of type A and type B monoamine oxidase (MAO) enzymes. The most active compound 3b (2-((2-(2-(4-(4-Nitrophenyl)thiazol-2-yl)hydrazineylidene)-2-phenylethyl)thio)benzothiazole) showed strong inhibitory activity at hMAO-A (IC₅₀ of 0.095?±?0.004?µM). Furthermore, compound 3i (2-((2-(2-(4-(2,4-dichlorophenyl)thiazol-2-yl)hydrazineylidene)-2-phenylethyl)thio)benzothiazole) showed significant inhibition profile on hMAO-A with the IC₅₀ values 0.141?±?0.006?µM.     

A new synthetic route to aminothiazolinones

Novel 2-(5-R-1,3,4-thiadiazol-2-yl)aminothiazolin-4-ones 6a—h and 2-imino-3-(5-R-1,3,4-thiadiazol-2-yl)thiazolidin-4-ones 7a—h were prepared by treating N-(5-R-1,3,4-thiadiazol-2-yl)thioureas 4a—h with chloroacetic acid on various solid supports under microwave irradiation. Tautomeric mixtures of compounds 6a—h and 7a—h were obtained in all cases. In alkaline and neutral media, compounds 6a—h were the major products, while in acid media, 7a—h were the major products.     

Synthesis of 1,3,4-thiadiazoles containing the trifluoromethyl group

The following compounds have been synthesized: 2-Amino-5-trifluoromethyl-1,3,4-thiadiazole; N-(5-trifluoromethyl - 1,3,4-thiadizol-2-yl)benzenesulfonamide; N¹-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)sulfanilamide, its N⁴-acetyl, N⁴-succinyl, and N⁴-pathalyl derivatives; o - m - and p-trifluoromethylbenzoylthiosemicarbazide, their corresponding 2-amino-1,3,4-thiadiazoles, their corresponding sulfanilamides, their N⁴-acetyl, N⁴-succinyl and N⁴-phthalyl derivatives; 3-o-trifluoromethylphenyl-4H-1,2,4-triazole-5-thiol. Preliminary in-vitro assays show that synthesized sulfanilamide derivatives have antibacterial activity against Staphylococcus aureus.     

Nano silver particles catalyzed synthesis,molecular docking and bioactivity of α-thiazolyl aminomethylene bisphosphonates

Abstract

A new series of α-thiazolyl aminomethylene bisphosphonates were synthesized by a three component reaction of 4-aryl substituted thiazol-2-amine with different dialkyl/aryl phosphites and triethyl orthoformate in the presence of Ag NPs (nano particles) as a catalyst under solvent free conditions. All the synthesized target compounds were characterized by ¹H, ¹³C, ³¹P, mass and elemental analysis. The target compounds were screened for their in vitro antioxidant, antibacterial and antifungal activity. Molecular docking studies were also performed. The results revealed that among the synthesized compounds tetramethyl(((4-(4-methoxyphenyl)thiazol-2-yl)amino) methylene)bis(phosphonate) (5d), tetramethyl(((4-(4-fluorophenyl)thiazol-2-yl)amino) methylene) bis(phosphonate) (5h), and tetramethyl(((4-(4-bromophenyl)thiazol-2-yl)amino)methylene) bis (phosphonate) (5j) showed remarkably higher antioxidant activity by DPPH and H₂O₂ than the standard ascorbic acid. Compounds tetramethyl(((4-phenyl thiazol-2-yl)amino) methylene) bis(phosphonate) (5a), 5d, 5h and tetraethyl(((4-(4-bromophenyl)thiazol-2-yl) amino)methylene)bis (phosphonate) (5k) showed good antibacterial activity. 5a, 5d, and 5h also showed rather higher antifungal activity than the standard flucanozole. Computational docking methods have been used to predict how several aminomethylene bisphosphonate derivatives compete against the inhibitor BPH-1330 at the crystal enzyme structure of the 4H3A protein active site and how R and R₁ influence their binding ability.     

Synthesis of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties and evaluation of their antifungal activity

A series of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties were synthesized from ethyl acetoacetate, thiourea, 3-pyridinylmethyl chloride hydrochloride, and substituted anilines by multi-step reactions. The structures of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis. The in vitro antifungal activities against Botrytis cinerea and Sclerotinia sclerotiorum were evaluated. The result showed that N-phenyl-6-methyl-2- ((pyridin-3-ylmethyl)thio) pyrimidin-4-amine (4a) displayed high inhibition activity against Botrytis cinerea with 87.5%inhibition at 100 µg/mL; 4a, and N-(4-isopropylphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4c), N-(4-methoxyphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4d) and N-(2-hydroxy-5-chloro)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin- 4-amine (4h) exhibited sufficient activities against Sclerotinia sclerotiorum with 86.6% –93.7% inhibitions at the same concentration.     

Synthesis and Characterization of Novel Chiral (1R,2R)-1,2-Bis[5-(Aminomethylphospinic Acid)-1,3,4-Thiadiazol-2-YL]Ethane-1,2-Diols

Abstract

(1R,2R)-1,2-bis[5-(arylideneamino)-1,3,4-thiadiazol-2-yl]ethane-1,2-diol (2a–d) were synthesized by using appropriate aldehydes and (1R,2R)-1,2-bis(5-amino-1,3,4-thiadiazol-2-yl)ethane-1,2-diol (1) as a starting compound. Then, the phosphinic acid component (3a–d) were obtained from (2a–d) and hypophosporus acid. In addition, the structures of the novel chiral compounds (2a–d) and (3a–d) were confirmed by elemental analyses, IR, ¹H-NMR, ¹³C-NMR, and ³¹P-NMR spectra.

¹H NMR and ¹³C NMR spectra for 1, 2a, and 3a (Figures S1–S6) are available online in the Supplemental Materials.     

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.