芳香醛与硫代巴比妥酸的缩合反应研究

通过微波辐射、用水作溶剂及在醋酸铵催化下的固相研磨等，研究了芳香醛与 硫代巴比妥酸的缩合反应。在三种反应条件下都得到了5-芳亚苄基硫代巴比妥酸， 并通过IR，~1H NMR和元素分析确定了产物的结构。     

无溶剂条件下5-亚烃基硫代巴比妥酸的合成

在无溶液和催化剂条件下，采用室温研磨、加热和微波辐射的方法，由芳香醛 和硫代巴比妥酸经Knoevenagel固相缩合反应高效率地制备了5-亚烃基硫代巴比妥 酸，产物结构经~1H NMR，~(13)C NMR和IR确证。     

5-(色酮基-3-次甲基)(硫代)巴比妥酸的合成

将巴比妥酸或硫代巴比妥酸、3-甲酰基色酮在乙酸-乙酸酐溶液(含乙酸酐10%)中进行缩合反应,制备了5-(色酮基-3-次甲基)(硫代)巴比妥酸.并经元素分析,IR,1H NMR及13C NMR确证了产物的结构.     

室温离子液体促进的5-亚芳基巴比妥酸衍生物的合成

在室温离子液体1-丁基-3-甲基咪唑四氟硼酸盐([bmim]BF₄)存在下, 采用室温研磨和微波辐射的方法, 由芳香醛和巴比妥酸或硫代巴比妥酸经Knoevenagel缩合反应, 制备了相应的5-亚芳基巴比妥酸或5-亚芳烃基硫代巴比妥酸衍生物. 在室温研磨条件下反应2 h, 产率为78%～96%, 在微波辐射功率为160 W时反应20 s, 产率为82%～98%, 产物结构经¹H NMR确证.     

取代-3-甲酰色酮与(硫代)巴比妥酸的固相缩合反应

在无溶剂无催化剂条件下,取代-3-甲酰色酮与(硫代)巴比妥酸通过固相Knoevenagel缩合反应合成了一系列5-(取代色酮基-3-亚甲基)(硫代)巴比妥酸,收率68.0%～85.5%,其结构经1H NMR确证.     

5-(吲哚基-3-次甲基)(硫代)巴比妥酸的合成

以冰乙酸为催化剂,吲哚-3-甲醛与巴比妥酸或硫代巴比妥酸在无水乙醇中进行Knoevenagel缩合,合成了5-(吲哚基-3-次甲基)巴比妥酸或5-(吲哚基-3-次甲基)(硫代)巴比妥酸,其结构经1H NMR和IR表征.     

5-(取代吡唑基-4-次甲基)(硫代)巴比妥酸的合成

以冰乙酸为催化剂,将取代吡唑甲醛和巴比妥酸或硫代巴比妥酸在无水乙醇中进行Knoevenagel缩合反应,合成了6个5-（取代吡唑基-4-次甲基）（硫代）巴比妥酸。标题化合物经IR、1^HNMR、元素分析确证结构。     

一种新的四硫富瓦烯衍生物的合成

经偶联、缩合等反应合成了一种新的用于分子组装的底物2,3-(二硫甲基)-6,7(二硫丁氧基对苯亚甲基巴比妥)四硫富瓦烯,产物用元素分析,IR和^1H NMR进行了表征,并初步探讨了其电化学行为。     

研磨法制备5－芳叉巴比妥酸

将巴比妥酸、芳香醛与无水ZnCl2于研钵中，室温研磨5min后放置，得到缩合 产物5－芳叉巴比妥酸，收率90％－97％。该法反应条件温和、操作简便、收率高。     

二茂铁甲醛与含活性亚甲基化合物的水相反应研究

二茂铁甲醛与具有活性亚甲基的化合物巴比妥酸 ( 2a)、硫代巴比妥酸 ( 2b)、2 ,2 二甲基 1,3 二烷 4,6 二酮 ( 2c)、1 苯基 3 甲基 5 吡唑啉酮 ( 2d)、氰乙酸乙酯 ( 2e)、2 ,4 戊二酮 ( 2f)、环己酮 ( 2g)及环戊酮 ( 2h)在水相中进行缩合反应 ,高产率简便地得到α 二茂铁亚甲基酮 .产物结构经1 HNMR ,1 3 CNMR ,IR及元素分析进行了表征 .     

Uncatalyzed Condensation Reactions between Aromatic Aldehydes and Thiobarbituric Acid in Water

A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis, IR and ^1H NMR spectra.     

硫代巴比妥酸分光光度法测定消毒液中戊二醛

在醋酸介质中，硫代巴比妥酸与戊二醛生成缩合产物，此产物在可见光区有最大吸收，籍此可测定微量戊二醛。线性范围为０．５－１０．０ｍｇ／Ｌ，检出限为０．０１９ｍｇ／Ｌ。方法灵敏度高，体系简单，操作简便，用本方法测定了消毒液中戊二醛的含量，结果满意。     

Reaction of barbituric/thiobarbituric acid with phosphines or phosphites and dialkyl acetylenedicarboxylates for synthesis of phosphorus zwitterions or phosphonate derivatives

Abstract

A three-component reaction between barbituric/thiobarbituric acid, phosphines, and dialkyl acetylenedicarboxylates in dry acetonitrile led to the formation of barbiturate/thiobarbiturate-functionalized stable zwitterionic salts in a one-pot process. When trialkyl phosphites were used instead of phosphines, barbiturate/thiobarbiturate-functionalized phosphonates were obtained in good yields.     

Comparison of spectrophotometric and HPLC methods for determination of lipid peroxidation products in rat brain tissues

Two methods for determination of lipid peroxidation (LPX) products in rat brain homogenates were compared. The thiobarbituric acid (TBA) test and HPLC assay for analysis of malondialdehyde (MDA) were applied. Rat brain homogenate dissolved in tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl) was mixed with TBA and H₃PO₄ and heated at 100°C to form colored complex that was extracted into butanol. No significant differences were found between the contents of TBA-reacting substances and their amount deduced from the MDA-TBA analysis. The presented results show that LPX products in brain homogenates can be determined without interferences also by the TBA test. Moreover, a survey of various methods used for the sample preparation before analysis of LPX products originating from different brain areas was made and compared with the obtained results.     

Uncatalyzed four-component synthesis of pyrazolopyranopyrimidine derivatives and their antituberculosis activities

Fused pyrazolopyranopyrimidines containing both biologically active pyranopyrazole and pyranopyrimidine compounds were synthesized using a one-pot, four-component reaction of ethyl aceto acetate, hydrazine hydrate, benzaldehydes, and thiobarbituric acid without catalyst in ethanol. All target compounds obtained in very good to excellent yields over short reaction times by adapting a simple workup procedure. All the synthesized compounds exhibited good to excellent antituberculosis activities. The results shown that 4-(1H-imidazol-2-yl)-3-methyl-7-thioxo-4,6,7,8-tetrahydropyrazolo[4’,3′:5,6]pyrano[2,3-d] pyrimidin-5(1H)-one (5a) is a good antitubercular agent, as good as the standard streptomycin drug, based on minimum inhibitory concentration (MIC).     

1‐n‐Butyl‐3‐Methylimmidazolium Tetrafluoroborate–Promoted Green Synthesis of 5‐Arylidene Barbituric Acids and Thiobarbituric Acid Derivatives

The room temperature ionic liquid 1‐n‐butyl‐3‐methylimmidazolium tetrafluoroborate ([bmim]BF₄) was used to promote the synthesis of 5‐arylidene barbituric acids and thiobarbituric acid derivatives under the solid‐state conditions of grinding or microwave irradiation without organic solvent. The yields were 77.9–96.2%. It is shown that the proposed method is fast, efficient, and environmentally benign.     

Studies on Spiroheterocycles,Part II: Heterocyclization of the Spiro Compounds Containing Cyclohexanone and Thiobarbituric Acid with Different Bidentate Nucleophilic Reagents

The reaction of thiobarbituric acid with different diarylidene ketones 1a–c yields the spiro compounds 2a–c. The diarylidene derivatives 3a–c are synthesized by the condensation of spiro compounds 2a–c with different aldehydes. A series of spiro heterocycles compounds 4a–l, 5a–l, 6a–l, 7a–l, 8a–l, and 9a–l are synthesized from the diarylidene compounds. The structures of the compounds are ascertained from their analytical and spectral data. Some of the compounds are screened for their biological activities.     

The Detection of Native Fluorescence in Peroxidized Fatty-Acids

Abstract

Peroxidized unsaturated fatty-acids show fluorescent properties in the absence of amino groups. Compounds formed from linolenic acid autooxidized for 5 days have been separated on thin-layer chromatograms with paired zero-time controls then located by their thiobarbituric acid and peroxidase reactivity. Spectrofluorimetric analysis of the eluted 5-day zones showed that two had ultraviolet fluorescence and a third visible fluorescence.