Synthesis, Crystal Structure, and Herbicidal Activities of 2-Cyanoacrylates Containing 1,3,4-Thiadiazole Moieties

Three series of novel 2‐cyanoacrylates 7a – 7f , 9a – 9f , 10a – 10f containing 1,3,4‐thiadiazole ring moieties were synthesized as herbicidal inhibitors of photosystem II (PS II) electron transportation. Their structures were clearly verified by ¹H NMR, ¹³C NMR, elemental analysis (or HRMS analysis) and single‐crystal X‐ray diffraction analysis. Bioassay showed that a suitable group at the 3‐position of acrylates was essential for high herbicidal activity. In particular, compound 7e showed the best herbicidal activities and gave 100% inhibitory activity against rape and amaranth pigweed at a dose of 1.5 kg/ha. Introduction of substituent with higher polarity such as sulfinyl or sulfonyl to the 5‐position of 1,3,4‐thiadiazole decreased herbicidal activities.     

Push-Pull Structures Based on 2-Aryl/thienyl Substituted Quinazolin-4(3H)-ones and 4-Cyanoquinazolines

Design and synthesis of 2-(aryl/thiophen-2-yl)quinazolin-4(3H)-ones and 4-cyano-2-arylquinazolines with Et₂N-, Ph₂N- or carbazol-9-yl- electron donating fragment are described. The key photophysical properties of these compounds have been studied by UV/Vis absorption and fluorescence spectroscopy in solvents of different polarity (toluene and MeCN). 2-(Aryl/thiophen-2-yl)quinazolin-4(3H)-ones show fluorescence in blue-green region in toluene solution with quantum yields up to 89% in the case of 2-(4’-N,N-diphenylamino[1,1’-biphenyl]-4-yl)-quinazolin-4(3H)-one. Moreover, triphenylamino derivative based on quinazolin-4(3H)-one with para-phenylene linker displays the highest quantum yield of 40% in powder. The fluorescence QY of Et₂N and Ph₂N derivatives decrease when going from toluene to MeCN solution, whereas carbazol-9-yl counterparts demonstrate strengthening of intensity that emphasizes the strong influence of donor fragment nature on photophysical properties. 4-Cyanoquinazolines are less emissive in both solvents, as well as, in solid state. The introduction of cyano group into position 4 leads to orange/red colored powder and dual emission bands. Some molecules demonstrate the increase in emission intensity upon addition of water to MeCN solution. According to frontier molecular orbitals (HOMO, LUMO) calculations, the energy gap of 4-cyanoquinazoline decreases by more than 1 eV compared to quinazolin-4-one, that is consistent with experimental data.     

5-芳酰氨基-2-苯基-2H-1, 2, 4-噻二唑-3-酮的合成

用1-芳酰基-5-苯基-2-硫代双脲与溴进行氧化成环反应制备了九个新的5-芳酰氨基-2-苯基-2H-1, 2, 4-噻二唑-3-酮, 相应的1-芳酰基-5-苯基-2-硫代双脲可以通过苯基脲与酰基异硫氰酸酯加成制得。     

Design,Synthesis and Antitumor Activity of Novel Indolin-2-one Derivatives Containing 4-Thiazolidinone Moiety

A series of novel indolin-2-one derivatives containing 4-thiazolidinone moiety(7a―7r) were synthesized and evaluated for their in vitro antitumour activities against MDA-MB-231(human breast cancer), H460(human lung cancer) and HT-29(human colon cancer) cell lines by standard 3-(4,5-dimethylthiazae-2-yl)-2,5-diphenyltetrazo- lium bromide(MTT) assay. Representative compounds(7d, 7k, 7m, 7p) with higher cytotoxicity were further examined against one normal cell line(WI-38, human fetal lung fibroblasts). The preliminary investigation shows that most of the compounds display moderate to excellent potency and high selectivity against different human cancer cell lines. In particular, the most potent compound 7m shows promising cytotoxicity against MDA-MB-231, H460 and HT-29 cell lines with IC₅₀ values of 0.78, 0.056 and 0.018 μmol/L, respectively. The potency is much higher than that of Sunitinib(IC₅₀=3.46 μmol/L against MDA-MB-231, IC₅₀=2.59 μmol/L against H460, IC₅₀=1.50 μmol/L against HT-29) by 4.4, 46.3 and 83.3 fold.     

Design,Synthesis and Antifungal Activity of Novel Thioureas Containing 1,3,4-Thiadiazole and Thioether Skeleton

To find new lead compounds with high antifungal activity, a series of new thiourea derivatives containing 1,3,4-thiadiazole and thioether skeleton was designed via linking the active sub-structures. The target compounds were prepared via three steps from the commercially available thiosemicarbazide. Their structures were characterized by means of HRMS, ¹H NMR, ¹³C NMR and IR spectroscopy. The preliminary results indicate that the title compounds show various antifungal activity against the tested fungi. Compounds 4c, 4g, 4h, 4k, 4n, 4o, 4p, 4q and 4r display excellent antifungal activities against one or more tested fungi with inhibitory efficiencies of 90%-100% at 200 μg/mL. Especially, compound 4o shows the best inhibitory effect against Curvularia lunata, Cotton Fusarium Wilt, P. P. var nicotianae and Fusarium spp. with the EC₅₀ values of 28.12, 30.41, 15.2 and 6.22 μg/mL, respectively, which are even superior to those of triadimefon(98.73, 96.58, 105.37 and 102.18 μg/mL). The preliminary structure-activity relationship indicates that allyl and aromatic groups are favorable to their antifungal activities.     

Synthesis of 2-aryl-5H-[1,3,4]-thiadiazolo[2,3-b]quinazolin-5-ones

3-Amino-2-thioxo-1,2,3,4-tetrahydroquinazolin-4-ones were converted into 2-aryl-5H-[1,3,4]thiadiazolo[2,3-b]quinazolin-5-ones on treatment with carboxylic acids and POCl₃. 3-Arylmethylidenamino-2-thioxo-1,2,3,4-tetrahydroquinazolin-4-ones also cyclized to 2-aryl-5H-[1,3,4]thiadiazolo[2,3-b]quinazolin-5-ones when oxidized with potassium chlorate in acetic acid, but on heating they were deaminated to give 2-thioxo-1,2,3,4-tetrahydroquinazolin-4-one and aryl nitriles. __________ Translated from Khimiya Geteotsiklicheskikh Soedinenii, No. 5, 787–791, May, 2006.     

2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-one: Synthesis and investigation of serine protease inactivation

Summary 2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-one was prepared by thermal treatment of 2-(3-benzoylthioureido)-4,5-dimethoxybenzoic acid and by benzoylation of 2-amino-6,7-dimethoxy-4H-3,1-benzoxazin-4-one. The inactivation of chymotrypsin and human leukozyte elastase by the title compound and 2-benzoylamino-4H-3,1-benzoxazin-4-one is reported.

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2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-on: Synthese und Untersuchung der Inaktivierung von Serin-Proteasen

Zusammenfassung 2-Benzoylamino-6,7-dimethoxy-4H-3,1-benzoxazin-4-on wurde durch thermische Behandlung von 2-(3-Benzoylthioureido)-4,5-dimethoxybenzoesäure und durch Benzoylierung von 2-Amino-6,7-dimethoxy-4H-3,1-benzoxazin-4-on hergestellt. Über die Inaktivierung von Chymotrypsin und humaner Leukozyten-Elastase durch die Titelverbindung und 2-Benzoylamino-4H-3,1-benzoxazin-4-on wird berichtet.

     

N-取代-6-(3-氯-4-氯甲基-2-氧吡咯烷-1-基)-7-氟-3,4-二氢-2H-1,4-苯并噁嗪-3-酮衍生物的合成与生物活性研究

采用生物活性基团拼接的分子设计方法, 将活性基团2-氧吡咯烷引入到2H-[1,4]苯并噁嗪-3(4H)-酮分子结构的苯环上, 设计并合成了16个未见文献报道的N-取代-6-(3-氯-4-氯甲基-2-氧吡咯烷-1-基)-7-氟-3,4-二氢-2H-1,4-苯并噁嗪-3-酮衍生物6a～6p, 其结构经IR, ¹H NMR, LC/MS和元素分析确证. 初步的生物活性测试结果表明, 部分化合物具有较高的除草和杀虫活性, 如6c～6f等化合物在用量为150 g/hm²时对苘麻(Abutilon theophrasti)、刺苋(Amaranthus spinosus)和藜(Chenopodium album L)等阔叶杂草具有90%以上的抑制率, 6l和6o在500 mg/L浓度下对蚕豆蚜(Aphis fabae)具有90%以上的致死率, 个别化合物还兼具除草及杀虫活性.     

Potentiometric and Thermodynamic Studies of 4-Sulfamethazineazo-3-methyl-1-phenyl-2- pyrazolin-5-one and Its Metal Complexes

Proton–ligand dissociation constants of 4-sulfamethazineazo-3-methyl-1-phenyl-2- pyrazolin-5-one (SMP) and metal–ligand stability constants of its complexes with bivalent metal ions (Mn²⁺, Co²⁺, Ni²⁺ , Cu²⁺, and Zn²⁺) have been determined potentiometrically in 0.1 M KCl, and a 40% (v/v) ethanol–water mixture. The order of the stability constants of the complexes was found to be Mn²⁺ < Co < Ni < Cu < Zn. The dissociation constants, pK ^H, of SMP and the stability constants, log K, of its complexes were determined at different temperatures and the corresponding thermodynamic parameters ( G, H, and S) were derived and discussed. The dissociation process is nonspontaneous, endothermic, and entropically unfavorable. The formation of the complexes were found to be spontaneous, endothermic, and entropically favorable.     

Synthesis,Antifungal Activity,and 3D-QSAR Study of Novel Nopol-Derived 1,3,4-Thiadiazole-Thiourea Compounds

A series of novel nopol derivatives bearing the 1,3,4-thiadiazole-thiourea moiety were designed and synthesized by multi-step reactions in search of potent natural product-based antifungal agents. Their structures were confirmed by FT-IR, NMR, ESI-MS, and elemental analysis. Antifungal activity of the target compounds was preliminarily evaluated by in vitro methods against Fusarium oxysporum f. sp. cucumerinum, Cercospora arachidicola, Physalospora piricola, Alternaria solani, Gibberella zeae, Rhizoeotnia solani, Bipolaris maydis, and Colleterichum orbicalare at 50 µg/mL. All the target compounds exhibited better antifungal activity against P. piricola, C. arachidicola, and A. solani. Compound 6j (R = m, p-Cl Ph) showed the best broad-spectrum antifungal activity against all the tested fungi. Compounds 6c (R = m-Me Ph), 6q (R = i-Pr), and 6i (R = p-Cl Ph) had inhibition rates of 86.1%, 86.1%, and 80.2%, respectively, against P. piricola, much better than that of the positive control chlorothalonil. Moreover, compounds 6h (R = m-Cl Ph) and 6n (R = o-CF₃ Ph) held inhibition rates of 80.6% and 79.0% against C. arachidicola and G. zeae, respectively, much better than that of the commercial fungicide chlorothalonil. In order to design more effective antifungal compounds against A. solani, analysis of the three-dimensional quantitative structure–activity relationship (3D-QSAR) was carried out using the CoMFA method, and a reasonable and effective 3D-QSAR model (r² = 0.992, q² = 0.753) has been established. Furthermore, some intriguing structure–activity relationships were found and are discussed by theoretical calculation.     

Synthesis and transformations of 2-(5-amino-(mercapto)-1,3,4-thiadiazolylthio)-7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidines

The reactions of 2-amino-5-mercapto-(or 2,5-dimercapto)-1,3,4-thiadiazoles with 2-bromo-7-methyl-5-oxo-5H-1, 3,4-thiadiazolo[3, 2-a]pyrimidine to give the corresponding sulfides have been studied. The possibility of S-alkylation and addition of quinone at the free mercapto group in the 1,3,4-thiadiazole ring has been shown. The reactions at the amino group with benzoyl chloride and chloroformates have been investigated. The conditions of cyciodehydration at the amino group with ethyl acetoacetate and bromination of the pyrimidine fragment of 7-methyl-5-oxo-5H-1,3,4-thiadiazolo[3,2-a]pyrimidine have been found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1954–1957, November, 1993     

3-[(5-取代硫基)-4H-1,2,4-三唑-3-基]苯并吡喃-2-酮的合成与抑菌活性

为寻找具有杀菌活性的三唑类先导化合物,采用活性亚结构拼接方法,将香豆素环和硫醚结构单元引入到三唑类化合物分子中,合成一系列未见文献报道的新型含香豆素环和硫醚结构的三唑类衍生物。经~1H NMR、~(13)C NMR、IR、MS和元素分析对所合成化合物的结构进行了表征。初步生物活性测试表明,部分目标化合物在试验浓度下具有一定的抑菌活性。     

Enzymatic Synthesis and Characterization of Novel Polycarbonates Derived from 5-Allyloxy-1, 3-dioxan-2-one and 5, 5-Dimethvl-1.3-dioxan-2-one

Novel polycarbonates from 5-allyloxy-1, 3-dioxan-2-one （ATMC） with 5, 5-dimethyl- 1, 3-dioxan-2-one （DTC） were successfully synthesized for the first time using immobilized porcine pancreas lipase （IPPL） as catalyst. The resulting copolymers were characterized by IR, ^1H NMR, ^13C NMR and GPC. The molecular weight （Mn） of the copolymer with molar feed ratio of 10：90 （ATMC：DTC） was 9300 and the polydispersity was 1.31, while the Mn increased to 14300 and polydispersity of 1.25 with the feed ratio of 50：50. Moreover, the composition of the copolymers agreed well with the monomer feed.     

Chemoselectivity of 6-bromo-2-methyl-3,1-benzoxazin-4-one towards amines,Schiff bases,and azines

Summary 6-Bromo-2-methyl-3,1-benzoxazin-4-one (1) undergoes an unusual cleavage at position 4 when it is allowed to react witho-phenylenediamine or anthranilic acid in dry benzene to give the corresponding compounds2–5, respectively. The reaction of1 withSchiffbases and azines results in the formation of the compounds6a–d and8a,b, respectively. The reaction involves a cleavage of theSchiff base or the azine into its amine and arylidene moieties which are smoothly incorporated into1 via nucleophilic attack of the amine at position 4 and condensation of the aldehyde with a reactive methyl group, at position 2 respectively. No displacement of the arylidene segment was observed.

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Zur Chemoselektivität von 6-Brom-2-methyl-3,1-benzoxazin-4-on gegenüber Aminen,Schiffschen Basen und Azinen

Zusammenfassung 6-Brom-2-methyl-3,1-benzoxazin-4-on reagiert mito-Phenylendiamin oder Anthranilsäure in trockenem Benzol unter einer ungewöhnlichen Bindungstrennung zu den Verbindungen2–5. Die Reaktion von1 mitSchiffschen Basen und Azinen führt zu den Verbindungen6a–d und8a,b. Die Reaktion verläuft über eine Spaltung derSchiffschen Base oder des Azins in ihre Amin- und Arylidenreste, die über einen nucleophilen Angriff des Amins an Position 4 und Kondensation des Aldehyds mit der reaktiven Methylgruppe in Position 2 glatt in1 übergeführt werden. Es wurde kein Arylidenaustausch beobachtet.

     

Synthesis and characterization of two new coordination supramolecular structures from a versatile unsymmetric 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot) ligand

Two new inorganic–organic coordination networks based on a versatile and unsymmetric building block 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione (Hpot) and inorganic Co^II and Cd^II salts have been synthesized in mixed solvent media and structurally characterized by single-crystal X-ray diffraction analysis. Crystal Hpot (1) was obtained from methanol solution. Reaction of Co(NO₃)₂ · 6H₂O with Hpot afforded a neutral two-dimensional (2-D) porous coordination polymer {[Co(pot)₂] · 6H₂O}_n (2) with a (4,4) network, which shows a 3-D supramolecular network through O–H?O weak interactions. While substituting the transition metal ions used in 2 with Cd(NO₃)₂ · 6H₂O, a neutral 2-D coordination polymer [Cd₂(pot)₄]_n (3) with a (6,3) network which further extended to a 3-D supramolecular structure through versatile hydrogen bonds C–H?X (X = O, N and S) was obtained. It is remarkable that the building block “pot” anion exhibits versatile coordination modes in complexes 2 and 3. These results indicate that the versatile nature of this rigid unsymmetric ligand, together with the coordination preferences of the metal centers, plays a critical role in construction of novel coordination polymers. The properties of gas absorption, magnetism and luminescence of 2 and 3 have been investigated and discussed in detail.     

Synthesis and Characterization of a Novel Copoly(aryl ether ketone) Containing 4, 4''''-Biphenyl-bis[4-phthalazin-1(2H)-one] Moiety

Poly(aryl ether ketone)s are a category of high performance engineering thermoplastics characterized by high glass transition temperature and excellent thermooxidative stability. And they have important applications in electronic, electric, aircraft and aerospace industries1~3. Considerable efforts have been made towards the improvement of solubility or processability of poly(aryl ether ketone)s4,5. In our work, a novel bis(phthalazinone) monomer 1 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] …     

Synthesis of 4-Amino-6-R-4,5-dihydro-3-phenacylthio-1,2,4-triazin-5-ones and 8H-3-R-7-Aryl-1,2,4-triazino[3,4-b][1,3,4]thiadiazin-4-ones

A study was carried out on the reaction of 4-amino-6-R-2,3,4,5-tetrahydro-3-thioxo-1,2,4-triazin-5-ones with halo ketones in alkaline media to yield 4-amino-6-R-4,5-dihydro-3-phenacylthio-1,2,4-triazin-5-ones, which then convert to 8H-3-R-7-aryl-1,2,4-triazino[3,4-b][1,3,4]thiadiazin-4-ones.