3-羟基-4-甲基-5-乙基-2(5H)-呋喃酮的合成

报道了以草酸二乙酯为原料,制备具有焦糖香味的香料化合物3-羟基-4-甲基-5-乙基-2(5H)-呋喃酮的方法:首先乙基溴化镁与草酸二乙酯通过格氏反应,以约50%产率生成2-氧代丁酸乙酯,然后其在碳酸钾的作用下发生缩合反应,以约94%产率得到3-羟基-4-甲基-5-乙基-5-乙氧羰基-2(5H)-呋喃酮,再通过水解、脱羧反应,得到3-羟基-4-甲基-5-乙基-2(5H)-呋喃酮.路线总收率约36%.     

2-氨基/乙酰氨基-7-溴-1,8-萘啶衍生物的合成

以2-氨基/乙酰氨基-7-羟基-1,8-萘啶为原料和POBr3反应,简单高效合成得到六个7-溴代1,8-萘啶衍生物L1-L6。反应在较高温度或延长反应时间下易产生自由基取代反应,通过对影响2-溴代1,8-萘啶产物产率的反应条件(反应温度、反应时间、有无自由基猝灭剂)进行优化,得到各7-溴代1,8-萘啶衍生物的最佳合成条件。化合物L1、L2、L3、L5的最佳合成条件为60℃(10min),若高温或延长时间反应,可加FeCl_3抑制自由基以保证产率;化合物L4、L6的最佳条件为100℃(30min)。优化的条件下,各7-溴代1,8-萘啶衍生物产率分别为57.2%、61.5%、56.8%、46.8%、62.7%和53.8%。     

7-取代-4-喹诺酮-2-羧酸甲酯的合成

4-喹诺酮-2-羧酸甲酯衍生物的制备,一般是用苯胺衍生物与丁炔二酸二甲酯反应,生成α-(取代苯胺基)丁烯二酸二甲酯(1),继之在二苯醚中约260℃加热环合而获得。我们用间氨基苯酚与丁炔二酸二甲酯在甲醇中反应,所得黄色固体经鉴定为7-羟基-4-喹诺酮-2-羧酸甲酯(2);除去固体后的滤液在甲醇-盐酸中回流还能生成2。若用间苯二胺与丁炔二酸二甲酯反应,则生成7-氨基-4-喹诺酮-2-羧酸甲酯(3)(产率20%)和N,N′-二(1,2-双-甲氧羰基乙烯基)间苯二胺(4)(产率4.8%)。这样就不需要再在二苯醚中进行环合。2与3的易于制备,显示氨基和羟基的活化作用。2和3在室温分别与醋酐-吡啶反应,可得乙酰化物5和6.2和3在二甲基甲酰胺中与乙氧草酰氯(ethyloxalyl chloride)反应,可分别生成化合物7和8。     

含联苯醚结构2(5H)-呋喃酮衍生物的合成

以硫酸为催化剂,不同4'-烷氧基-4-羟基联苯与粘卤酸在甲苯溶剂中回流,经脱水醚化反应合成了16个新型的5-(4'-烷氧基-4-联苯氧基)-3,4-二卤-2(5H)-呋喃酮化合物,产率30%~58%(大部分47%以上).中等产率可能与该酸催化的反应为SN2亲核取代反应有关.新化合物的结构经FTIR,UV,1H NMR,13C NMR和元素分析确证.这些具有不同生物活性基团化合物的设计与合成,为新型2(5H)-呋喃酮衍生物的合成,以及由不同羟基化合物合成芳香醚类化合物提供了参考.     

三氯化铟高效催化3-(1-吡咯基)吲哚-2-酮类化合物的合成方法

使用三氯化铟在乙醇中回流的条件下催化不同的靛红衍生物与4-羟基脯氨酸反应,以较高的产率(83-99%)和纯度合成得到了相应的产物3-(1-吡咯基)吲哚-2-酮化合物,并对这个反应做了一个比较全面系统的研究.     

9, 9-二(3-氨基-4-羟基苯基)呫吨的合成

以醋酸酐为溶剂, 将9, 9-二(4-羟基苯基)呫吨与浓硝酸在15 ℃左右发生硝化反应1.5 h, 形成中间体-9, 9-二(3-硝基-4-羟基苯基)呫吨, 产率为88.5%;继而以Pd/C 为催化剂, 80%的水合肼为还原剂, 在乙醇和1, 4-二氧六环混合溶剂中, 于70 ℃将中间体进行还原反应10 h, 得到目标产物9, 9-二(3-氨基-4-羟基苯基)呫吨, 产率为90.8%, 两步反应总收率为80.4%。 中间体与目标化合物经NMR、FTIR和元素分析等确定了它们的结构。     

5-甲氧基-2-[(E)-(6-甲基吡啶-2-亚氨基)甲基]苯酚的合成与表征

研究了以2-羟基-4-甲氧基苯甲醛和2-氨基-6-甲基吡啶为原料合成新型席夫碱化合物5-甲氧基-2-[(E)-(6-甲基吡啶-2-亚氨基)甲基]苯酚的方法。当2-羟基-4-甲氧基苯甲醛与2-氨基-6-甲基吡啶摩尔比为1∶1.6,反应时间为6 h,反应温度为75℃时,反应产率最高。采用元素分析、UV-Vis、IR、1H NMR、X-射线单晶衍射等方法进行结构表征。该化合物为单斜晶系,空间群P21/c,a=1.1886(3)nm,b=0.65948(16)nm,c=1.6897(4)nm,β=108.505(3)°,V=1.2560(5)nm3,Dc=1.281 g·cm-3,Z=4,F(000)=512,μ=0.087 mm-1,R1=0.0477,wR2=0.1342。通过π···π堆积和分子内氢键O2-H2···N1、C8-H8A···N2形成较稳定的晶体结构,并具有蓝色荧光。     

3β-羟基雄甾-4-烯-6,17-二酮合成的一种新方法

以去氢表雄酮(1)为原料,经过氯铬酸吡啶(PCC)氧化得到雄甾-4-烯-3,6,17-三酮(2),然后在Co2+存在下用NaBH4还原,得到芳香酶的强效抑制剂3β-羟基雄甾-4-烯-6,17-二酮(3)。与文献合成方法相比,反应步骤缩短,反应产率提高。化合物3的结构经NMR和IR测试技术进行了表征,与文献结果一致。     

2-羟基脱氧雌酚酮的合成

2-羟基雌甾化合物是人体内对生理机能有重要意义的雌激素代谢产物,其在生物体内的含量极少,需用化学方法合成来满足研究、应用的需要。迄今为止,已报道了较多合成2-羟基和4-羟基雌甾化合物的方法[1-3],但选择性和产率并不十分理想。我们在文献报道的合成路线[1]的基础上,合成了     

2-芳甲酰氨基硫羰基-3-异噻唑酮及4-氰基-5-甲硫基-2-芳甲酰氨基硫羰基-3-异噻唑酮的合成与生物活性

通过3-羟基异噻唑(4)和4-氰基-5-甲硫基-3-羟基异噻唑(5)分别与芳酰基异硫氰酸酯(3)反应,合成标题化合物2-芳甲酰氨基硫羰基-3-异噻唑酮(6a_6f)和4-氰基-5-甲硫基-2-芳甲酰氨基硫羰基-3-异噻唑酮(7a_7e),对此反应及产物的结构特点进行了探讨.     

Silica Gel Catalyzed Stereoselective Conversion of Dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates to Dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-2-butenedioates in Solvent-Free Conditions

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-hydroxy-2-acetonaphthone leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with conjugate base to produce dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates. Silica gel was found to catalyze conversion of dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates to dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-2-butenedioates in solvent-free conditions at 90°;C in fairly good yields.     

Microwave Induced Conversion of Dialkyl 2-(3-Acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene)Butanedioates to Dialkyl 2-(3-Acetyl-4-hydroxy-1-naphthyl)-2-butenedioates in the Presence of Silica Gel Powder in Solvent-Free Conditions

Protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates, by 1-hydroxy-2-acetonaphthone leads to vinyltriphenylphosphonium salts, which undergo aromatic electrophilic substitution reaction with conjugate base to produce dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates. Microwave was found to catalyze conversion of dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-3-(triphenylphosphoranylidene) butanedioates to dialkyl 2-(3-acetyl-4-hydroxy-1-naphthyl)-2-butenedioates in the presence of silica gel powder in solvent-free conditions.     

Synthesis and Alkylation of 4-(2-Chlorophenyl)-3-cyano-6-hydroxy-5-(2-thienoyl)-6-trifluoromethylpiperidin-2-thione

4-(2-Chlorophenyl)-3-cyano-6-hydroxy-5-(2-thienoyl)-6-trifluoromethylpiperidin-2-thione, which was used for the synthesis of 2-allylthio-4-(2-chlorophenyl)-3-cyano-6-hydroxy-5-(2-thienoyl)-6-trifluoromethyl-1,4,5,6-tetrahydropyridine, was obtained by the reaction of 2-thienoyltrifluoroacetone with 2-chlorophenylphenylmethylenecyanothioacetamide or with a mixture of 2-chlorobenzaldehyde and cyanothioacetamide in the presence of N-methylmorpholine. The molecular and crystal structure of the piperidinthione have been established by X-ray crystallography.     

Novel,Simple, and Efficient Synthesis of 3-(2-(5-(Benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one Derivatives via a One-Pot,Four-Component Condensation Reaction

The synthesis of 3-(2-(5-(benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one derivatives was achieved through a one-pot, four-component reaction involving condensation of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, thiosemicarbazide, phenacylcyanaide, and various aryl aldehydes in dry alcohol and few drops of acetic acid under reflux condition. This four-component reaction has some advantages such as ease of handling, good yields, and easy workup. All structures of newly prepared compounds were confirmed by analytical and spectral data.     

Synthesis of Derivatives of 4-Hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinoline and 2-[2-(4-Hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-one

From 4-hydroxy-2-methylquinoline-3-propionyl chlorides hydrochlorides the corresponding thiosemicarbazides were synthesized. The cyclization of the latter both in alkaline and acidic media furnished 4-hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinolines. The reaction of the above propionyl chlorides with anthranilic acid afforded the corresponding 2-[2-(4-hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-ones.     

Hydrolysis Reactions and Resolution of (±)-2-Acetamido-3-hydroxy-1-(4-nitrophenyl)-1-propanone

IntroductionChloramphenicol,which was isolated fromStreptomyces venezuelae in 1 947[1] ,is used as abroad- spectrum antibiotic possessing activityagainst many Gram- negative and Gram- positivemicroorganisms. (± ) - 2 - Acetamido- 3 - hydroxy- 1 -(4- nitrophenyl) - 1 - propanone[(± ) - 1 ]is one of theintermediates of producing chloramphenicol.Petrow et al.[2 ] reported some transformations of(± ) - 1 in hydrolysis reactions. However,thereaction products were complicated under multiplehydr…     

Novel synthesis of 2-(trifluoromethyl)- and 2-(perfluoroalkyl)-2-hydroxy-2H-chromenes and their regiospecific reaction with silyl enol ethers

The synthesis of substituted 2-(trifluoromethyl)- and 2-(perfluoroalkyl)-2-hydroxy-2H-chromenes 2a-o was achieved in good yields by intramolecular cyclization of 3-(perfluoroalkyl)-3-phenoxypropenals 1 in the presence of aluminum chloride. Then a Lewis acid mediated nucleophilic reaction with silyl enol ethers 3 proceeded with complete regiospecificity to afford 4-functional 2-(trifluoromethyl)- and 2-(perfluoroalkyl)-4H-chromenes 4a-p with high yields.     

2-[4-(2,6-二氟苯基)噻唑-2-基]-3-羟基丙烯腈衍生物的合成及生物活性

为了寻找生物活性良好的噻唑基丙烯腈类化合物, 利用2-[4-(2,6-二氟苯基)噻唑-2-基]乙腈(3)分别与取代氯甲酸酯4和取代苯基异氰酸酯6在碱存在下反应, 合成了8个2-[4-(2,6-二氟苯基)噻唑-2-基]-3-羟基-3-烃氧基丙烯腈化合物5和7个2-[4-(2,6-二氟苯基)噻唑-2-基]-3-羟基-3-取代苯胺基丙烯腈化合物7, 均为首次报道的丙烯腈类化合物. 化合物结构经1H NMR, IR, MS和元素分析表征. 初步生物活性测定结果表明, 在试验浓度下, 目标化合物均具有一定的杀虫和抑菌活性, 其中化合物5f和5h在100 mg/L浓度下对炭疽病菌的抑制率达95%; 化合物5g和7d在250 mg/L浓度下对棉红蜘蛛的致死率达85%.     

Efficient Synthesis of N-[(2-Hydroxyethoxy)methyl]-2-alkyl-3-hydroxy-4-pyridinone by a Modified Hilbert-Johnson Reaction

Ethyleneglycol derivatives of 2-methyl (and ethyl)-3-hydroxy-4-pyridinone were synthesized by a modified Hilbert-Johnson reaction. The synthesis proceedes by reaction of O-protected 2-alkyl-3-hydroxy-4-pyridinone with hexamethyldisilazane in the presence of chlorotrimethylsilane followed by trimethylsilyl trifluoromethanesulfonate catalized alkylation with benzyloxy-ethoxymethylchloride in dichloroethane and deprotection by hydrogenation. The overall yield was 87%. This method provides a useful way to produce oligo- or polyethyleneglycol substituted hydroxypyridinones.     

Synthesis, Structure, and Alkylation of N-Methylmorpholinium 5-[2-Cyanoethyl-1-(4-hydroxy-3-methoxyphenyl)-2-thiocarbamoyl]-2,2-dimethyl-6-oxo-1,3-dioxa-4-cyclohexen-4-olate

N-Methylmorpholinium 5-[2-cyanoethyl-1-(4-hydroxy-3-methoxyphenyl)-2-thiocarbamoyl]-2,2-dimethyl-6-oxo-1,3-dioxa-4-cyclohexen-4-olate was obtained from the reaction of 4-hydroxy-3-methoxybenzaldehyde with cyanothioacetamide and Meldrum's acid in the presence of N-methylmorpholine. The molecular and crystal structure of the title compound have been established and its alkylation has been studied.