1,3-偶极环加成合成新型4,5-二氢-2′,5′-二氧杂吡咯啉并[4,5-c]异噁唑衍生物

N-取代苯基马来酰亚胺与α-氯代-1,2,3-三唑-4-甲醛肟和α-氯代-喹喔啉-2-甲醛肟在三乙胺作用下通过1,3-偶极环加成合成了一系列4,5-二氢-2′,5′-二氧杂吡咯啉并[4,5-c]异(口恶)唑衍生物.化合物结构经元素分析,IR, 1H NMR及MS得到确证.     

N-Substituted 4,5-dihydro-1,2-benzothiazepin-3-one 1,1-dioxide

The reaction of 2-carboethoxyethyl-4,5-dimethoxybenzene sulfochloride with substituted pyridines leads to the corresponding sulfonamides. The latter were hydrolysed to the acids, on which a general method for preparing a new ring system was based.     

5-Schwefelsubstituierte 1,2-Dithiol-3-one

1, 2-Dithioles with sulfur substitutents in position 5 are prepared by reaction of 4-chloro-1, 2-dithiol-3-ones with thiols, sulfinates, dithiocarbamates, or potassium ethylxanthate. Bis-(4-chloro-1, 2-dithiol-3-on-5-yl) sulfide is produced from 4, 5-dichloro-1, 2-dithiol-3-one with sodium thiosulfate and other thiol forming reagents. The 5-alkylthio- and 5-arylthio-1, 2-dithiol-3-ones can be oxidized with peracids to sulfoxides and, partly, to sulfones; the sulfones can also be obtained from sulfinates. 4-Chloro-5-(α-methyl-benzylthio)-1, 2-dithiol-3-one reacts differently with peracetic acid, giving bis-(4-chloro-1, 2-dithiol-3-on-5-yl) disulfide besides 4-chloro-1, 2-dithiol-3-one. With oxalyl chloride, 4-chloro-5-alkylthio-1, 2-dithiol-3-ones form 3, 4-dichloro-dithioliumchlorides, which react with anilines to give 3-phenylimino-4-chloro-5-alkylthio-1, 2-dithioles.     

5-亚环己基-2-取代氨基咪唑啉酮类化合物的合成及其杀菌活性研究

以环己酮和2-硫代乙内酰脲为起始原料,经Knoevenagel缩合反应制得5-亚环己基-2-硫代咪唑啉-4-酮(1),化合物1在乙醇钠/乙醇体系中与碘甲烷反应得到5-亚环己基-2-甲硫基咪唑啉-4-酮(2),化合物2再与相应的取代苯胺或苄胺在冰醋酸体系中回流制得目标化合物5-亚环己基-2-取代氨基咪唑啉酮3a～3r,它们的化学结构经1H NMR,IR,MS和X-ray单晶衍射确证.5-亚环己基-2-对氯苄氨基咪唑啉酮(3q):Mr=335.83,C16H18ClN3O CH4O,Monoclinic,P2(1)/n,ρ=1.264 g/cm3,F(000)=712,Z=4,a=0.59895(12)nm,b=1.2161(2)nm,c=2.4289(5)nm,β=94.03(3)°.初步生物活性测定结果表明:在50μg/mL浓度下,部分目标化合物均对供试菌种显现出一定的抑制活性,其中5-亚环己基-2-对氟苄氨基咪唑啉酮(3p)对油菜菌核的EC50为24.37μg/mL,3q对辣椒疫霉的EC50为28.68μg/mL.     

5-芳亚甲基-2,3-二芳基噻唑-4-酮类衍生物的合成及抑菌活性研究

本文以多个2,3-二芳基噻唑-4-酮为底物,利用微波辅助的方法合成了18个5-芳亚甲基-2,3-二芳基噻唑-4-酮类衍生物,并测定了它们对7种植物病原菌的抑菌活性。它们的结构经熔点、1H NMR和MS确证。抑菌活性试验显示,化合物4g和4n表现出潜在的抑菌活性。     

4-取代-3-烷基-4,5-二氢-1-(3-氯-4-氟苯基)-1,2,4-三唑-5-酮的合成及生物活性

为寻找活性强、作用时间长的新型非肽类血管紧张素II AT₁受体拮抗剂, 从易得原料3-烷基-4,5-二氢-1-(3-氯-4-氟苯基)-1,2,4-三唑-5-酮出发, 经过N-烃化反应、1,3-偶极反应、氢解、水解和酰化等反应, 合成得到一系列4-取代-3-烷基-4,5-二氢-1-(3-氯-4-氟苯基)-1,2,4-三唑-5-酮类衍生物, 总收率为58%～87%, 其结构经IR, ¹H NMR, MS和元素分析确证. 初步药理试验结果表明: 所有目标化合物均有一定的AT₁受体拮抗活性, 其中化合物12d抑制AII诱导的兔主动脉环收缩的IC₅₀值为4.0×10^－9 mol/L, 与阳性药坎地沙坦(candesartan)相当, 具有进一步的研究意义.     

新型2-氨基-5-苯亚甲基-4H-咪唑啉-4-酮衍生物的合成及生物活性

通过烯基膦亚胺1与芳基异氰酸酯的aza-Wittig反应得到碳二亚胺2,再用2与亲核试剂的成环反应制得10个新型的2-氨基-5-苯亚甲基-4H-咪唑啉-4-酮衍生物4,探讨了碳二亚胺2与不同亲核试剂反应的活性并分离得到了一个胍中问体3i,初步研究了化合物4的生物活性.     

4a-Alkyl Derivatives of 5-Oxo-4H-4a,5-dihydroindeno[1,2-b]pyridine

High selectivity has been discovered for the C-alkylation of ambident anions of 5-oxo-1H-4,5-dihydroindeno[1,2-b]pyridines with ethyl bromoacetate, allyl, propargyl, and phenacyl bromides, which leads to the formation of the corresponding 4a-substituted 5-oxo-4H-4a,5-dihydroindeno[1,2-b]pyridines in high yield.     

Design and Synthesis of Pyrido[1,2-e]purin-4（3H）-one Derivatives as Potential PDE 5 Inhibitors

A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.     

A Novel Photochemical Reaction of 4-Bromo-3-methyl-1- phenyl-4,5-dihydro-pyrazol-5-one

UV-Irradiation of 4-bromo-3-methyl-l-phenyl-4,5-dihydro-pyrazol-5-one (1) in the presence of various aromatic hydrocarbons gave different types of photoproducts depending on the nature of the hydrocarbons via an electron-transfer mechanism. In the presence of naphthalene or phenanthrene a photochemical homocoupling reaction of 1 occurred to form 2 or 2 and 3, respectively.     

Crystal and Molecular Structure of Acylalmino Derivatives of 1-(2,4,6-Trichlorophenyl)-4,5-dihydropyrazol-5-one

The structure of acylamino derivatives of 1-(2,4,6-trichlorophenyl)-4,5-dihydropyrazol-5-one was studied by X-ray diffraction. 3-Acetylamino-1-(2,4,6-trichlorophenyl)-4,5-dihydropyrazol-5-one and 3-benzoylamino-1-(2,4,6-trichlorophenyl)-4,5-dihydropyrazol-5-one exist in crystal as CH tautomers. The nature and number of acylamino groups were found to affect the nature of intermolecular hydrogen bonds in the crystals studied.     

Synthesis of new heterocyclic phenols: 9-Hydroxypyrido[1,2-a]pyrimidin-4-one and Derivatives

9-Hydroxypyrido[1,2-a]pyrimidin-4-one ( 5 ) was prepared by condensation of 2-amino-3-hydroxypyridine with isopropylidene aminomethylenemalonate. The reaction first led to an enaminoester intermediate which underwent cyclization by heating at 250° affording the new heterocyclic phenol 5 . A similar condensation performed on 2-amino-3-benzyloxypyridine yielded the corresponding benzylic ether which can be easily debenzylated to 5 by hydrogenolysis. Furthermore 2-amino-3-benzyloxypyridine condensed with diethyl ethoxymethylenemalonate gave 9-benzyloxy-3-ethoxycarbonylpyrido[1,2-a]pyrimidin-4-one which was also debenzylated to the corresponding free phenol.     

Tautomerism and Acid-Base Properties of Formyl Derivatives of 1-Phenyl-3-methyl-4,5-dihydropyrazol-5-one and Its Thio Analog

A single-crystal X-ray diffraction study showed that 1-phenyl-3-methyl-4-formyl-4,5-dihydropyrazol-5-one occurs in the solid phase as two conformers of the NH tautomer. The acidity and basicity constants of 1-phenyl-3-methyl-4-formyl-4,5-dihydropyrazol-5-one and its analog, -5-thione, in 50% aqueous dioxane were measured. PM3 calculations qualitatively explan the differences in the tautomerism and acid-base properties of 4-formylpyrazolone (-pyrazolethione) and the corresponding compounds without the formyl substituent.     

3-Halotetrahydropyran-4-one Derivatives from Homopropargyl Acetal

A gold(I)-catalyzed regioselective method for the preparation of 3-bromo/iodo-tetrahydropyran-4-one derivatives from homopropargyl acetal is reported. A one-pot procedure based on a gold(I)-catalyzed Petasis–Ferrier rearrangement/cyclization and subsequent electrophilic halogenation was developed. Corresponding hemiacetals were not suitable substrates for the formation of the 3-halo-pyran derivatives. The present transformation is a useful method to readily afford highly substituted 3-halo-tetrahydropyran-4-ones, which are suitable substrates in a variety of reactions in further synthesis.     

Reaction of 1,2-Diamino-4,5-diphenylimidazole with 1,3-Diarylpropenones and Their Dibromo Derivatives

The reaction of 1,2-diamino-4,5-diphenylimidazole with 1,3-diarylpropenones and 1,3-diaryl-2,3-dibromopropenones gives dihydro- and heteroaromatic derivatives of 6-hydroxyimidazopyrimidines and also imidazopyrimidines which do not contain the 6-hydroxy group. It was found that the structure of the products depended on the conditions for carrying it the reaction.     

Synthesis and Characterization of New Thiazolidin-4-one Derivatives

The synthesis of some new functionalized thiazolidin-4-one derivatives has been described. The N-substituted-thiosemicarbazides 3a-3i were obtained though the reaction of alkylamines 2a–2i , carbon disulfide, and hydrazine hydrate. The condensation reaction between 3a–3i and 4-amino-2-methanesulfanylpyrimidine-5-carboxaldehyde 1 afforded the thiosemicarbazones 4a–4i . The corresponding thiazolidin-4-ones 5a–5i were prepared by cyclization of 4a–4i with ethyl bromoacetate. The structures of the final products were confirmed by IR, ¹ H NMR, ¹³ C NMR, and HRMS.