Diethyl 1-(p-fluoro­phenyl)-5-oxo-3-(2-thienyl)­pyrrolidine-2,2-di­carboxyl­ate

In the title compound, C₂₀H₂₀FNO₅S, the pyrrolidine ring adopts an envelope conformation. The fluoro­phenyl and thio­phene rings are individually planar. The molecular and crystal structures are stabilized by intra- and intermolecular C—H⋯O interactions.     

(S)-1-(2-氯乙酰基)吡咯烷-2-甲酸的制备及晶体结构

以L-脯氨酸和氯乙酰氯为原料合成维格列汀的重要中间体(S)-1-(2-氯乙酰基)吡咯烷-2-甲酸(1)。甲醇体系室温挥发14 d培养得到1的无色透明块状晶体,通过单晶X-射线衍射技术对其进行结构解析。结果表明1晶胞属于正交晶系,P2₁2₁2₁空间群,分子式为C₇H₁₀NO₃Cl,相对分子质量为191.61 g/mol,立体构型和预测构型一致,确证了1的空间结构。      

3-溴-1-(3-氯-2-吡啶基)-1H-吡唑-5-甲酸的合成

以2,3-二氯吡啶为起始原料,通过水合肼亲核取代、马来酸二乙酯环合制得2-(3-氯-2-吡啶基)-5-氧-3-吡唑烷甲酸乙酯(5);5经苯磺酰氯酯化、溴化氢溴化制得3-溴-1-(3-氯-2-吡啶基)-4,5-二氢-1H-吡唑-5-甲酸乙酯(7);7经脱氢、水解合成了用于制备氯虫酰胺的关键中间体--3-溴-1-(3-氯-2-吡啶基)-1H-吡唑-5-甲酸,总收率39.5%,其结构经~1H NMR和MS确证.     

Synthesis,Spectroscopic Properties,and Quantum Mechanical Study of 5-Oxo-1-phenyl-4-(piperidin-1-ylmethyl)pyrrolidine-3-carboxylic Acid

Russian Journal of Organic Chemistry - The spectroscopic properties of 5-oxo-1-phenyl-4-(piperidin-1-ylmethyl)pyrrolidine-3-carboxylic acid were investigated using FT-IR, NMR, and UV techniques and...     

Synthesis and Crystal Structure of 1-（Trifluoromethyl）-1-（propioloyl）-（E）-3-oxo-（2-thienyl）-（2-naphthylamine）

1INTRODUCTIONTheSchiffbasesderivedfromb-diketonesandaliphaticamineshavebeenshowntoexistastheketo-amines.However,ifsubstituentseitherattheketooraminogrouparearomatic,itmaybeexpectedtheenoliminewillbethefavoredtautomericform[1].Recently,someSchiffbasesderivedfromTTA(4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione)andPMBPhavebeenstudiedbyWang[2]andYu[3]etal.Inordertostudytherelationshipbetweenthestructuresandperformancesofthesecompounds,thetitlecom-poundwillbereportedherein.2EXPERIMENT…     

Crystal Structure and Photochromic Properties of [1-(2-Methyl-5-(4-cyanophenyl)-3-thienyl)]-2-(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene

A new photochromic diarylethene, [1-(2-methyl-5-(4-cyanophenyl)-3-thienyl-2-(2-methyl-5-phenyl-3-thienyl)]perfluorocyclopentene(1o, C28H17F6NS2), was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. Its crystal belongs to the monoclinic system, space group P21/c with a = 24.1381(5), b = 9.3834(6), c = 11.1073(8), β = 94.477(4)°, Z = 4, V = 2508.1(3) A3, D3 c = 1.445 mg/m, μ = 0.275, F(000) = 1112, the final R = 0.0482 and wR = 0.1429 for 5834 observed reflections(I 2σ(I)). Further study demonstrated the diarylethene underwent reversible photochromism, changing between colorless and blue in hexane solution, crystalline phase and PMMA films, respectively.     

Synthesis of 3-substitued 5-(2-thienyl)isoxazoles

The reaction of 3,4,4-trichloro-1-(2-thienyl)but-3-en-1-one with hydroxylamine gave 3-hydroxyiminomethyl-5-(2-thienyl)isoxazole which was converted into 5-(2-thienyl)isoxazole-3-carbonitrile by the action of acetic anhydride in pyridine. 5-(2-Thienyl)isoxazole-3-carbonitrile reacted with hydroxylamine to produce the corresponding amide oxime. Heterocyclization of its O-acyl derivatives in acetic acid afforded 5-substituted 3-[5-(2-thienyl)isoxazol-3-yl]-1,2,4-oxadiazoles.     

5-(4-氯苯基)-1-(2,4-二氯苯基)-4-甲基吡唑-3-羧酸的合成

对氯苯丙酮经三甲基氯硅烷保护后与草酸单乙酯单酰氯缩合制得4-(4-氯苯基)-3-甲基-2,4-二氧代丁酸乙酯(4);4与2,4-二氯苯肼盐酸盐缩合成腙、再经分子内环合、水解合成了制备利莫那班的关键中间体——5-(4-氯苯基)-1-(2,4-二氯苯基)-4-甲基吡唑-3-羧酸,总收率30.3%,其结构经1HNMR和MS确证。