新型3-(1,3,4-噻二唑基)-1,3-苯并噁嗪类化合物的合成和杀菌活性

以2-[(1,3,4-噻二唑基-2-氨基)甲基]苯酚和CH2Cl2为原料,首次采用相转移催化法合成了一系列新型3-(1,3,4-噻二唑基)-1,3-苯并噁嗪类化合物,产率为47%～62%.研究了相转移催化剂的用量、反应物用量、反应温度等对反应产率的影响.产物结构用IR,1H NMR,13C NMR和元素分析进行了表征.初步研究了目标化合物的杀菌活性,大部分化合物具有一定的杀菌活性.     

高效液相色谱法测定3-氨基哌啶二盐酸盐中氨基吡啶类基因毒性杂质的含量

在降血糖药物苯甲酸阿格列汀的合成过程中,有可能因原料的因素而引入氨基吡啶类基因毒性杂质而对上述药物的用药安全性造成影响。为此试验提出了用高效液相色谱法测定3-氨基哌啶二盐酸盐中3种氨基吡啶化合物(4-氨基吡啶、3-氨基吡啶和2-氨基吡啶)的方法。称取试样0.3g,用磷酸盐缓冲溶液(pH 7.0)-甲醇(90+10)混合溶液超声溶解并定容至10.0mL。选择Shim-pack Scepter C_(18)色谱柱作为分离柱,用pH 7.0的磷酸盐缓冲溶液和甲醇(90+10)的混合溶液等度洗脱,流量为0.5mL·min~(-1),柱温为35℃,检测波长为280nm,进样量10μL。在选定的条件下,上述3种化合物可达到很好的分离,4-氨基吡啶、3-氨基吡啶和2-氨基吡啶间的分离度分别为30.3,8.4,其检出限(3S/N)分别为0.028 9,0.071 1,0.070 2mg·L~(-1)。在3个浓度水平上对3种化合物进行回收试验,测得回收率依次为101%,98.4%,97.2%。重复性和重现性试验所测得3种化合物测定值的相对标准偏差(n=6)分别依次为1.5%,0.90%,0.70%和6.2%,3.0%,2.2%。样品加标溶液和对照品溶液在室温下放置24h内稳定性良好。     

2-(2-喹啉偶氮)-1,5-二氨基苯固相萃取光度法测定痕量钯

根据2-(2-喹啉偶氮)-1,5-二氨基苯(QADAB)与钯的显色反应及MCI-GEL反相固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量钯的方法.在0.2～3.0 mol·L-1高氯酸介质中,溴化十六烷基三甲胺(CTMAB)存在下,QADAB与钯反应生成2:1稳定络合物,该络合物可被MCI-GEL反相固相萃取小柱萃取富集,富集的络合物用丙酮洗脱后用光度法测定,在丙酮介质中体系的最大吸收波长为600 nm,表观摩尔吸光率为9.63×104L·mol-1·cm-1.钯质量浓度在0.01～L 5 mg·L-1内符合比耳定律,方法用于几种实样中痕量钯的测定,测得回收率在86%～96%间.     

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。     

浊点萃取-石墨炉原子吸收光谱法测定食品包装材料中锑

以吡咯烷二硫代氨基甲酸铵(APDC)为络合剂,在pH5.0乙酸-乙酸钠缓冲溶液中,痕量锑(Ⅲ)与APDC生成络合物,加入表面活性剂TritonX-114用浊点萃取分离富集样品中痕量锑。分取部分表面活性剂相用0.1mol·L-1硝酸甲醇溶液溶解,所得溶液直接用石墨炉原子吸收光谱法进行测定。对影响浊点萃取的因素和共存离子的干扰等进行了试验并予以优化。方法的检出限(3σ/k)为0.37μg.L-1。应用所提出的方法测定了食品包装材料陶瓷样品中锑的含量,并用标准加入法进行方法的回收试验,测得回收率为99.3%。     

紫外光照还原-流动注射分光光度法测定海水中硝酸盐

在pH 8.2的二乙三胺五乙酸-三羟甲基氨基甲烷(DTPA-Tris)缓冲介质中,通过紫外光照射使NO3-还原为NO2-后,与显色剂反应生成吸收峰位于540 nm波长处的化合物,据此提出了在线紫外光照还原流动注射分光光度法测定海水中硝酸盐。经试验,选择30 g·L-1氯化钠溶液作为载流,所选定的反应圈及样品环的长度依次为180 mm和130 mm。硝酸盐的质量浓度在0.009~3.0 mg·L-1范围内与相应的吸光度呈线性关系,其检出限(3s/k)为4.63μg·L-1。对同一天然海水样品按此法测定其NO3-含量10次,测得其平均值为0.538 mg·L-1,相对标准偏差为0.34%,并求得NO3-的还原率为80%。另在6个海水样品中各加0.50 mg·L-1NO3-标准溶液,按方法做回收试验,测得其回收率在97%以上。     

基质固相分散-高效液相色谱法测定虫草中甘露醇

提出了用基质固相分散-高效液相色谱法测定虫草中甘露醇.将虫草样品与石墨化碳黑球以质量比为1比4充分研磨后装柱,用热水洗脱,洗脱液中的甘露醇用高效液相色谱法测定.以Waters Sugar-Pak 1钙型阳离子交换柱为固定相,水为流动相,蒸发光散射检测器检测.方法的检出限(3S/N)为0.15 rag·L-1.方法应用于虫草样品的分析,测得相对标准偏差(n=7)均小于1.5%;在实样基础上作加标回收试验,测得回收率在97%～103%之间.     

新型受阻胺光稳定剂3-（2，2，6，6-四甲基哌啶4-氨基）丙酸十二酯的合成

建立了受阻胺光稳定剂3-(2,2,6,6-四甲基哌啶-4-氨基)丙酸十二酯的合成工艺.以2,2,6,6-四甲基-4-哌啶胺、丙烯酸甲酯为原料,经M ichael加成,生成的3-(2,2,6,6-四甲基哌啶-4-氨基)丙酸甲酯再与十二醇进行酯交换反应制得.并对所涉及的酯交换反应的工艺参数进行了优化.实验结果表明,四异丙基钛酸酯催化剂的催化效果最好;在3-(2,2,6,6-四甲基哌啶-4-氨基)丙酸甲酯与十二醇的摩尔比为1∶1.10,四异丙基钛酸酯催化剂的用量为反应物总质量的0.30%,反应温度180℃,反应时间8 h的条件下,酯交换反应收率为90.6%.该工艺总收率为86.3%.目标产物及中间体的结构通过MS进行了表征.     

“一锅法”合成2-氨基-N,3-二甲基-5-卤代苯甲酰胺

报道了从3-甲基-2-氨基苯甲酸出发一锅三步合成2-氨基-N,3-二甲基-5-卤代苯甲酰胺的方法.3-甲基-2-氨基苯甲酸(1)与固体光气反应生成中间体8-甲基-2H-3,1-苯并噁嗪-2,4(1H)-二酮(2),化合物2与甲胺水溶液发生胺解反应生成2-氨基-N,3-二甲基苯甲酰胺(3),3再与氯代丁二酰亚胺(NCS)、溴代丁二酰亚胺(NBS)或碘代丁二酰亚胺(NIS)发生芳香亲电取代反应生成目标产物2-氨基-N,3-二甲基-5-卤代苯甲酰胺(4～6).整个反应过程不需分离中间产品,最终产物经减压浓缩除去有机溶剂后,直接从水中析出针状晶体,总收率达到87%～94%,较文献报道的分步法收率提高30%以上.该方法工艺操作简单、反应条件温和、反应时间短、收率高,是一条环境友好的绿色合成路线.     

固相萃取-气相色谱-质谱法测定饮用水中36种农药残留量

提出了固相萃取-气相色谱-质谱联用法测定饮用水中36种农药的残留量。样品用石墨化碳/氨基复合型小柱净化和富集后,经DB-1701P弹性石英毛细管柱分离,用电子轰击离子源及选择离子监测扫描模式进行质谱测定。36种农药在一定浓度范围内呈线性关系,检出限(3S/N)在0.001 3～0.070mg.L-1之间。按方法在水样的基础上加入农药混合标准溶液做回收试验,测得回收率在90.8%～112.4%之间,测定值的相对标准偏差(n=5)在3.20%～13.2%之间。     

The synthesis and liquid crystal properties of some 4-n-nonylphenyl esters of 3-(4'-n-alkoxybiphenylyl)- and 3-(4'-n-alkoxybiphenylyl)-3-methyl-propanoic acids and their laterally fluorinated analogues

A number of 4-n-nonylphenyl esters and mono- and di-fluorinated 4-n-nonylphenyl esters derived from 3-(4'-n-alkoxybiphenylyl)propanoic acids (II) have been synthesized and their thermotropic liquid crystal properties assessed with a view to obtaining tilted smectic phases for possible use in ferroelectric display devices. Many of these compounds exhibit wide temperature range S_C and S_I/F phases, but none gave the ideal phase sequence S_C-S_A-N-I mainly because the structure of these compounds was not conducive to the formation of the nematic phase. To try to alleviate this problem a series of 4-n-nonylphenyl esters based on 3-(4'-n-alkoxybiphenylyl)-3-methylpropanoic acid was prepared, where a lateral methyl group was incorporated in the β-position of the -CH₂CH₂CO₂- linkage. Incorporation of the lateral methyl group encouraged the formation of a nematic phase at the expense of both the smectic A phase and tilted smectic phases.     

反相高效液相色谱法测定1-(对偶氮苯)-3-(5-氯-2-吡啶)-三氮烯

采用ZORBAX Ec lipse XDB-C8(4.6 mm i.d.×150 mm,5μm)色谱柱,乙腈流动相,流速0.70 mL.m in-1,检测波长407 nm,建立了测定1-(对偶氮苯)-3-(5-氯-2-吡啶)-三氮烯的反相高效液相色谱法.该方法线性范围0.5-8.0 mg.L-1,相对标准偏差为2.5%(c=5.0 mg.L-1,n=5),回收率在95.7%-105%之间.     

Synthesis of [N-methyl-3H]-7-chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2 H-1,4-benzodiazepin-2- one (3H-fludiazepam) by phase transfer catalysis

[N-methyl-3H]-7-Chloro-1,3-dihydro-5-(2-fluorophenyl)-1-methyl-2H-1,4- benzodiazepin-2- one ( [3H]fludiazepam) was prepared by phase transfer catalytic N-methylation of the corresponding nor-derivative with [3H]methyl iodide [407 GBq/mmol (11 Ci/mmol)] in a radiochemical yield of 34%. The specific activity was 271.6 GBq/mmol (7.34 Ci/mmol).     

2-(2-甲基烯丙基)-3-(3-甲基-1,2-丁二烯基)环己-2-烯酮重排生成八元环化合物反应机理的理论研究

采用密度泛函理论B3LYP/6-31G(d,p)方法研究了2-(2-甲基丙烯基)-3-(3-甲基-1,2-丁二烯基)环己-2-烯酮重排生成八元环化合物在气相中的反应机理. 考虑了两条可能的反应途径: 途径1包含5个过程, 途径2包含两个过程. 从能量上看, 两条途径的决定速度步均是[1,5]氢迁移. 采用自洽反应场极化连续模型(PCM模型)和极化导体模型(CPCM模型)研究了反应体系在甲苯溶液中的溶剂效应. 结果表明, 气相和溶液中途径2均是较优途径, 并且甲苯对该反应的溶剂化效应不明显. 理论研究结果与实验观察结果一致, 并很好地解释了有关实验现象.     

Studies on the behaviour of α-, β- and γ-cyclodextrins and some derivatives under reversed-phase liquid Chromatographic conditions

The separation processes of α-, β- and γ-cyclodextrins and their various methyl derivatives have been investigated with Knauer polarimetric (Chiralyser) and refractive index (RI) detectors. RP18 and RP8 hydrocarbon packings and an NH₂ bonded phase were applied as stationary phases. Aqueous methanolic or ethanolic solutions were used as mobile phases. It has been found that the Chiralyser detector response is approximately linear at low concentrations of solutes and that its detection capabilities are about 40 times better than those of the RI detector. Differences in the order of elution of α-, β- and γ-cyclodextrins have been observed for various stationary phases as well as for various mobile phase compositions. The optimal conditions for analytical determinations of cyclodextrins and their derivatives have been discussed.     

Reactions of 3-(4-Aryl-2-thiazolyl)- and 3-(2-Benzothiazolyl)-2-iminocoumarins with N-Nucleophiles

The reaction of 3-(4-aryl-2-thiazolyl)- and 3-(2-benzothiazolyl)-2-iminocoumarins with N-nucleophiles was studied. This reaction gives 2-N-substituted 3-(4-aryl-2-thiazolyl)- and 3-(2-benzothiazolyl)iminocourmarins. N-Nucleophiles such as arylamines, heterocyclic amines, and hydrazine derivatives undergo this reaction.     

Surface characterization of 1-butyl-3-methylimidazolium Br-, I-, PF6-, BF4-, (CF3SO2)2N-, SCN-, CH3SO3-, CH3SO4-, and (CN)2N- ionic liquids by sum frequency generation

Sum frequency generation spectroscopy, SFG, was used for the surface characterization at the gas-liquid interface of the 1-butyl-3-methylimidazolium cation combined with the following anions: Br-, I-, PF6-, BF4-, (CF3SO2)2N- (imide), SCN-, CH3SO3- (MeSO3), CH3SO4- (MS), and (CN)2N- (DCN). The SFG spectra obtained for the different ionic liquids were similar independent of the anion selected; therefore, a comprehensive analysis for the surface characterization of the ionic liquids' cation was focused only on the PF6- and Br- anion combinations. For an accurate identification of the vibrational modes observed, FT-IR and Raman spectroscopy in combination with isotopic labeling with deuterium and polarized Raman spectroscopy was used. The cation orientation was determined by analysis of polarization-dependent SFG spectra. For a compound dried in a vacuum to < or = 2 x 10(-5) Torr, the cation appears to be oriented with the ring laying flat along the surface plane and the butyl chain projecting into the gas phase independent of the anion identity.     

Theoretical study on the geometry and vibration of 1-[6-(4-Chlorophenyl)-1-[(6-chloropyridin-3-yl)methyl]-2-[(6-chloropyridin-3-yl)methylsulfanyl]-4-methyl-1,6-dihydropyrimidin-5-yl]ethanone

The solid phase FT-IR and FT-Raman spectra of 1-[6-(4-chlorophenyl)-1-[(6-chloropyridin-3-yl)methyl]-2-[(6-chloropyridin-3-yl)methylsulfanyl]-4-methyl-1,6-dihydropyrimidin-5-yl]ethanone (C25H21Cl3N4OS) were recorded in the region 4000-400 and 3500-100cm(-1), respectively. The vibrational spectra have been computed using density functional theory (B3LYP) and ab initio molecular orbital calculation (HF) with 6-31G(d, p) basis sets. A close agreement was achieved between the observed and calculated frequency by employing normal coordinate calculations. The observed and simulated spectra were found to be well comparable.     

Lithiation of 3-(Acylamino)-2-unsubstituted-, 3-(Acylamino)-2-ethyl-, and 3-(Acylamino)-2-propyl-4(3H)-quinazolinones: Convenient Syntheses of More Complex Quinazolinones(1)

3-(Pivaloylamino)- and 3-(acetylamino)-4(3H)-quinazolinones react with alkyllithium reagents to give 1,2-addition products in very good yields. Lithiation takes place with LDA and is regioselective at position 2. The lithium reagents thus obtained react with a variety of electrophiles to give the corresponding substituted derivatives in very good yields. Reactions of the lithium reagents with iodine give oxidatively dimerized cyclic structures. 3-(Pivaloylamino)- and 3-(acetylamino)-2-ethyl-4(3H)-quinazolinones and 3-(pivaloylamino)- and 3-(acetylamino)-2-propyl-4(3H)-quinazolinones are lithiated at the benzylic position with LDA. The lithium reagents so produced also react with a variety of electrophiles to give the corresponding 2-substituted-4(3H)-quinazolinone derivatives in very good yields. However, lithiation of 3-(acylamino)-2-(1-methylethyl)-4(3H)-quinazolinones was unsuccessful, as were lithiations of compounds having a diacetylamino group at position 3. The amide groups have been cleaved in good yield under basic or acidic conditions from some of the products to provide access to the free amino compounds.     

2-Hydroxy-5-(ethanolamino)-3-(10'-Z-pentadecenyl)-1,4-benzoquinone, new microbial phase II metabolite of maesanin

The use of microbial models for biotransformation of the natural benzoquinone, maesanin (1), resulted in the isolation of an ethanolamine conjugate (5) from the culture broth of Debaryomyces polymorphus ATCC 20280. Metabolite 5 was characterized as 2-hydroxy-5-(ethanolamino)-3-(10'-Z-pentadecenyl)-1,4-benzoq uinone. The production of 5 represents a new type of phase II conjugation reaction in microbial systems. The results of preliminary mammalian metabolism of 1 in rats were inconclusive.