Synthesis,Characterization,X-ray Crystal Structure and Safener Activity of Chiral 2-(3-Methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl)-2-oxoethyl Acetate

The new title compound, chiral 2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）- 2-oxoethyl acetate, has been synthesized via reduction, cyclization and acylation reaction. The structure of the product has been confirmed by IR, 1H NMR, 13C NMR, LC-MS （ESI） and single-crystal X-ray diffraction. （R）-2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）-2-oxoethyl acetate crystallizes in monoclinic, space group P21/c with a = 11.867（2）, b = 8.4087（2）, c = 14.325（6） A^°, β = 117.59（2）°, Z = 4, V = 1266.9（6） A^°3, Dc = 1.307 g/cm^3, F（000） = 528, μ（MoKα） = 0.097 mm-1, R = 0.0453 and wR = 0.1237; （S）-2-（3-methyl-2,3-dihydrobenzo[b][1,4]oxazin-4-yl）-2-oxoethyl acetate belongs to the triclinic system, space group P with a = 8.2647（17）, b = 8.7034（17）, c = 9.5479（19） A^°, α = 105.33（3）, β = 100.95（3）, γ = 105.14（3）°, Z = 2, V = 614.1（2） A^°3, Dc = 1.348 g/cm^3, F（000） = 264, μ（MoKα） = 0.10 mm-1, R = 0.0613 and wR = 0.1037. Both of the molecules prefer to form crystal packing through C–H…O hydrogen bonds.

Synthesis, Spectroscopic and Crystal Structure Studies on Ethyl 5,7-Dimethyl Coumarin-4-Acetate

Ethyl ester of 5,7-dimethyl coumarin-4-acetic acid has been synthesized from 3,5-Xylenol in a two step sequence of reaction involving Pechmann cyclisation and acid catalyzed esterification. The title compound 2 crystallizes in Monoclinic form, space group P 1 21/c 1, with a = 8.6248(4) ?, b = 18.9103(8) , c = 8.4204(4)?, β = 101.241(2)?, V = 1347.00(11) ?, D cal = 1.283 Mg/cm3, Z = 4. The molecule is stabilized by intermolecular C-H … O bonds.

Ni/ZrO_(2)-SO_(4)^(2-)催化剂的制备及其催化甲烷与CO_(2)制乙酸性能

以Zr(NO_(3))4·5H_(2)O和Ni(NO_(3))2·6H_(2)O为原料、(NH4)2CO_(3)为沉淀剂,采用溶胶凝胶-硫酸酸化两步法制备了Ni/ZrO_(2)-SO_(4)^(2-)催化剂,采用XRD,FTIR,SEM,N_(2)吸附-脱附,H_(2)-TPR,NH3-TPD等方法对Ni/ZrO_(2)-SO_(4)^(2-)催化剂进行表征,考察了Ni的引入方式对催化剂的结构和性能的影响。实验结果表明,与共沉淀方式引入Ni制备的Ni/ZrO_(2)-SO_(4)^(2-)催化剂相比,采用溶胶凝胶方式引入Ni制备的催化剂的四方相ZrO_(2)占比更高,表面酸量更多,且具有良好的热稳定性和较强的L酸性;采用溶胶凝胶方式引入Ni制备的Ni/ZrO_(2)-SO_(4)^(2-)催化剂的乙酸生成量明显优于共沉淀方式引入Ni制备的Ni/ZrO_(2)-SO_(4)^(2-)催化剂。四方相ZrO_(2)、酸性位点和过渡金属Ni之间的协同作用促进了甲烷与CO_(2)直接反应合成乙酸。

Catalytic Hydrogenation over Palladium Complex of Molecular Complex of Poly(4-vinylpyridine) with Acetic Acid

The palladium complex of the molecular complex of poly(4 vinylpyridine) with acetic acid(PVP/ HAc Pd) was prepared. Its catalytic activity for the hydrogenation of nitrobenzene was found much higher than that of the corresponding palladium complex of poly(4 vinylpyridine). In the presence of a strong inorganic alkali, especially potassium hydroxide, the catalytic activity is greatly improved. The suitable hydrogenation condition for PVP/HAc Pd is to use 0 1 mol/L ethanol solution of potassium hydroxide as the hydrogenation medium and the hydrogenation is carried out at 45 ℃.

Effect of lead acetate toxicity on experimental male albino rat

Objective:To evaluate the effect of different doses of lead acetate(1/20,1/40 and 1/60 of LD_(50))on body weight gain,blood picture,plasma prolein profile and the function of liver,kidney and thyroid gland.Methods:Male albino rats were divided into four groups,the first group represented the health control animals,while the second,third and fourth groups were ingested orally with sub lethal doses of load acetate(1/20,1/40 and 1/60)of the oral LD_(50),respectively.One dose was ingested every two days during the experimental period(14 weeks)including the adaptation time.Blood was collected and used for all analysis.Results:The results showed that,the ingestion of Pb^(2+)induced significant stimulation in glutamic-pyruvic transaminase(ALT)and glutamic-oxalacetic transaminease(AST)activity.Also,total soluble protein and albumin contents of plasma were significantly decreased,while the content of globulin was changed by the Pb^(2+)treatments.The cholinesteiase activity was inhibited,but the activities of alkaline and acid phosphates and lactate dehydrogenase were stimulated,while plasma glucose level was elevated as a result of lead acetate intoxication.In case of blood picture,Pb^(2+)ingestion reduced the contents of hemoglobin and RBCs count of intoxicated rat's blood and the plasma levels of T3,T4 and blood WBCs count were decreased.Conclusions:It can be concluded that lead acetate has harmful effect on experimental male albino rats.Therefore,the present work advises people to prevent exposure to the lead compound to avoid injurious hazard risk.

Synthesis of Acetic Acid on Pd-H_4SiW_(12)O_(40)-Based Catalysts by Direct Oxidation of Ethylene

Synthesis of acetic acid by direct oxidation of ethylene on Pd-H4SiW12O40-based catalysts was studied in a fixed-bed integral reactor and a pulse differential reactor. From the performance of the catalysts with different compositions and configurations, it is proposed that acetic acid is predominantly produced via an intermediate of acetaldehyde. This can be easily confirmed by comparing the product distributions in the integral and the differential reactors. The active sites for acetic acid formation are considered to exist mainly at the boundaries between the H4SiW12O40 and the Pd particles. The Pd-based catalysts reduced by H2/N2 have higher activities than those reduced by hydrazine, as explained by the degree of Pd dispersion obtained from the characteristics of hydrogen chemical adsorption. It was found that the Pd-Se-SiW12/SiO2 catalyst with selenium tetrachloride as a precursor was more active than that with potassium selenite, and that the acetic acid yield can be greatly increased by adding a suitable amount of dichloroethane (C2H4C12/C2H4 mole ratio=0.03) to the reactants.

Synthesis and Molecular Structure of Acetic Acid-3,5-diacetoxy-2-acetoxymethyl-6-(4-quinoxalin-2-yl-phenoxy)-tetrahydro-pyran-4-yl-ester

The title compound, acetic acid-3,5-diacetoxy-2-acetoxymethyl-6-（4-quinoxalin- 2-yl-phenoxy）-tetrahydro-pyran-4-yl-ester 8 （C28H28N2O10, Mr = 552.54）, has been synthesized and its crystal structure was determined by X-ray diffraction analysis. It crystallizes in monoclinic, space group P21, a = 10.060（8）, b = 5.648（4）, c = 24.11（2）A, β = 91.078（10）°, Z = 2, V= 1369.9（19）A^3, Dc = 1.339 g/cm^3,μ（MoKa） = 1.03 cm^-1, F（000） = 580.00, T =. 193.1 Kx-9 θmax = 25.03, （△/σ）max = 0.0000, Flack = -0.0（24）, the final R = 0.0680 and wR = 0.140 （w = 1/[0.0016Fo^2 ＋ 1.00000（Fo^2）]/（4Fo^2）） for 3126 observed reflections （1 〉 20（/））. The pyranoid ring adopts chair conformation in the sugar moiety, and all of the acetyl groups are in the e bond of the pyranoid ring, so the sugar moiety is very stable.

Al_(2)(SO_(4))_(3)催化热解油转化生产酯类燃料

酸类、糖类等不稳定组分的存在是制约热解油直接用作生物燃料的主要因素。为了解决此问题,提出采用Al_(2)(SO_(4))_(3)催化剂将这些不稳定成分酯化为燃料类化合物的途径。首先,分别以单模型化合物左旋葡萄糖或乙酸为原料,考察各种金属硫酸盐催化其转化制备乙酰丙酸乙酯或乙酸乙酯的能力,筛选出催化性能最好的催化剂;其次,以左旋葡萄糖和乙酸的模型混合物为原料,探究Al_(2)(SO_(4))_(3)催化同时转化制备酯类的最佳反应条件;最后,以真实热解油为原料,验证Al_(2)(SO_(4))_(3)在最佳反应条件下催化酯化的可行性。结果表明,酯化后热解油中大部分酸、糖、醛消失,同时产生大量的酯和缩醛,酯类和缩醛类占改性热解油总色谱面积的39.5%。Al_(2)(SO_(4))_(3)能有效将热解油中的酸类、糖类等不稳定组分酯化为燃料类化合物,可为热解油转化制备生物燃料提供借鉴。

SO₄^2-/SnO₂-Catalyzed C3-alkylation of 4-hydroxycoumarin with secondary benzyl alcohols and <i>O</i>-alkylation with <i>O</i>-acetyl compounds

Sulfated tin oxide (STO) has been found to be an efficient reusable solid superacid catalyst for C3-alkylation and O-alkylation of 4-hydroxycoumarins with benzylic, allylic alcohols/and corresponding acetates respectively, in acetic acid under reflux conditions with good yield of products.

SYNTHESIS OF ASYMMETRIC ETHERS CLEAVAGE OF ACYCLIC ACETALS WITH ZrCl_4-LiAlH_4

In this paper, we investigated the selective cleavage of acyclic acetals with the reagent system, ZrCl_4-LiAlH_4. The results indicate that this system is very useful for the cleavage of acyclic acetals to the corresponding asymmetric ethers.

CONVERSION OF ACETALS AND KETALS TO CARBONYL COMPOUNDS PROMOTED BY ZrCl_4-NaBH_4

In our study on the chemistry of ZrCl_4-NaBH_4,we have found that aldehydes and ketones can be regenerated from acetals and ketals at 30℃ in Et_2O in high yield The reaction mechanism was discussed.

Development of <i>α</i>-Amino Acid Detection with Peroxyoxalate Chemiluminescence by Using Water-Acetonitrile-Ethyl Acetate Mixed Solution

Peroxyoxalate chemiluminescence was, for the first time, examined by using ternary mixed solutions of water-hydrophilic/hydrophobic organic solvent. Eosin Y as a model fluorescence compound was dissolved with the ternary solutions of water (1.0 mM carbonate buffer, pH 9.0)-acetonitrile-ethyl acetate, water-rich of 15:3:2 volume ratio and organic solvent-rich of 3:8:4 volume ratio, to which bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide chemiluminescence reagent were added. The chemiluminescence observed with the ternary solutions, especially the organic solvent-rich solution, showed a larger signal than that observed with the water only solution or water-acetonitrile mixed solution. Chemiluminescence in the presence of twenty types of α-amino acid was similarly examined by using the ternary organic solvent-rich solution. The chemiluminescence of three α-amino acids with fluorescence properties was enhanced with the ternary solution. The data reported here may contribute to development of a new, sensitive peroxyoxalate chemiluminescence detection system.

肿瘤血管破坏剂5,6-二甲基黄嘌呤-4-乙酸对小鼠Lewis肺癌转移的抑制作用及机制

目的探讨肿瘤血管破坏剂5,6-二甲基黄嘌呤-4-乙酸(DMXAA)对小鼠Lewis肺癌(LLC)转移的抑制作用及其机制。方法制备2种小鼠肿瘤模型(LLC异位移植瘤小鼠模型和转移型LLC小鼠模型),评价DMXAA对LLC转移的抑制作用。LLC异位移植瘤小鼠模型制备成功后,随机分为3组:模型组(含1%DMSO的生理盐水,ip,2天1次)、模型+苏尼替尼组(30 mg·kg^(-1),ip,2天1次)和模型+DMXAA组(25 mg·kg^(-1),ip,给药1次)。首次给药后每隔1天测量小鼠移植瘤体积,并绘制移植瘤体积生长曲线和小鼠体重变化曲线;给药后2和5 d剥瘤称取瘤重,并将瘤组织进行免疫荧光染色,测定血小板内皮细胞黏附分子1(CD31)和α平滑肌肌动蛋白(α-SMA)阳性表达,计算α-SMA/CD31荧光强度比值,表示移植瘤组织血管表面周细胞覆盖率;哌莫硝唑(pimonidazole)染色检测瘤组织低氧程度。转移型LLC小鼠模型制备成功后,随机分为3组:模型组(含1%DMSO的生理盐水,ip,1周2次)、模型+苏尼替尼组(60 mg·kg^(-1),ip,1周2次)和模型+DMXAA组(25 mg·kg^(-1),ip,给药1次)。首次给药后2和5周用小动物活体成像系统观察小鼠体内肿瘤转移,并进行荧光定量分析。结果与模型组相比,模型+苏尼替尼组和模型+DMXAA组移植瘤体积和重量均显著减小(P<0.05,P<0.01);模型+苏尼替尼组小鼠体重明显下降(P<0.05),而模型+DMXAA组则无显著差异。与模型组相比,苏尼替尼对LLC转移无影响,而给药后2周DMXAA明显抑制LLC转移(P<0.01)。给药后5 d,模型+苏尼替尼组和模型+DMXAA组移植瘤组织中周细胞覆盖率均显著升高(P<0.05);模型+苏尼替尼组瘤组织低氧面积无明显变化,模型+DMXAA组瘤组织低氧面积显著降低(P<0.01)。结论肿瘤血管破坏剂DMXAA显著抑制小鼠LLC生长和转移,其机制可能与其诱导肿瘤血管正常化和改善瘤组织低氧微环境有关。

4,4′-二苯甲烷二胺与碳酸二甲酯合成4,4′-二苯甲烷二氨基甲酸甲酯

研究了无水乙酸锌〔Zn(CH3COO)2〕催化下4,4′-二苯甲烷二胺(MDA)与碳酸二甲酯(DMC)合成4,4′-二苯甲烷二氨基甲酸甲酯(MDC)的反应。用高效液相色谱/质谱/质谱联用仪对反应体系副产物进行了检测分析。结果表明,MDC生成的适宜工艺条件为:催化剂用量n〔Zn(CH3COO)2〕∶n(MDA)=5∶1,反应物配比n(DMC)∶n(MDA)=20∶1,反应温度180℃,反应时间2 h。在该条件下MDC收率为98%,MDA转化率100%。分析结果表明,主要副产物为单氨基甲酸酯和3种N-甲基化物。在上述基础上,讨论了N-甲基化物可能的生成机制和副产物的形成对MDC生成的影响。

SO_4^(2-)/TiO_2-MoO_3催化合成丁醛乙二醇缩醛的研究

以固体超强酸SO4 2 - /TiO2 MoO3为催化剂 ,对以丁醛和乙二醇为原料合成丁醛乙二醇缩醛的反应条件进行了研究。实验表明 :SO4 2 - /TiO2 MoO3是合成丁醛乙二醇缩醛的良好催化剂 ,较系统地研究了醛醇摩尔比、催化剂用量、反应时间诸因素对收率的影响。最佳反应条件为 :n(丁醛 )∶n(乙二醇 ) =1∶1.3 ,催化剂用量为反应物料总质量的 0 .5 %,环己烷为带水剂 ,反应时间 45min。上述条件下 ,丁醛乙二醇缩醛的收率可达 68.1%。

固体超强酸催化剂SO_4^(2-)/TiO_2-WO_3的制备及其催化性能研究

制备了固体超强酸催化剂SO2 -4/TiO2 WO3 ,并以丁酸丁酯的合成作为探针反应 ,系统考察了WO3 的含量、硫酸浸渍浓度、焙烧温度等制备条件对SO2 -4/TiO2 WO3 催化活性的影响 .实验表明 :制备催化剂的适宜条件为m(H2 WO4) =12 5 % ,硫酸浸渍浓度为 1 0mol·L-1,焙烧温度为 5 80℃ ,活化时间 3h .利用优化条件下制备的催化剂SO2 -4/TiO2 WO3 催化合成缩醛 (酮 ) ,在醛 /酮与二元醇 (乙二醇 ,1,2 丙二醇 )的投料摩尔比为 1∶1 5 ,催化剂的用量占反应物总投料质量的 0 5 % ,反应时间为 1h条件下 ,2 甲基 2 乙氧羰甲基 1,3 二氧环戊烷的收率为 78 7% ,2 ,4 二甲基 2 乙氧羰甲基 1,3 二氧环戊烷的收率为 83 0 % ,环己酮 -乙二醇缩酮的收率为 85 9% ,环己酮 1,2 丙二醇缩酮的收率为 84 6% ,丁酮 -乙二醇缩酮的收率为70 7% ,丁酮 1,2 丙二醇缩酮的收率为 88 3 % ,2 丙基 1,3 二氧环戊烷的收率为 80 6% ,4 甲基 2 丙基 1,3 二氧环戊烷的收率为 79 6% ,2 异丙基 1,3 二氧环戊烷的收率为 64 2 % ,4 甲基 2 异丙基 1,3 二氧环戊烷的收率为 83 3 % ,2 苯基 1,3 二氧环戊烷的收率为 75 3 % ,4 甲基 2 苯基 1,3 二氧环戊烷的收率为 95 1% .

TiCl_4水解法制备TiO_2薄膜的表征及光催化性能

以TiCl4水解法,采用浸渍提拉法在玻璃片上制备TiO2纳米薄膜。用XRD及SEM、EDS测定和表征TiO2薄膜的表面形貌和结构特性,以UV吸收光谱和可见光透光率表征薄膜的光学特性。结果表明,所得薄膜负载质量与镀膜次数有很好的线性关系,镀膜4次的TiO2薄膜具有表面均匀、厚度约为0 192μm,粒子粒径约为5.0nm,对紫外光强烈吸收并有红移拓宽。TiO2薄膜作为催化剂对500mL的20mg/L乙酸的降解率达到75.9%,比等负载量的粉末TiO2光催化的48.0%降解率高27.9%。

2-甲基-4-三氟甲基-5-噻唑甲酸的合成工艺改进

以三氟乙酰乙酸乙酯2与硫酰氯反应生成2-氯-4,4,4-三氟乙酰乙酸乙酯3,3与硫代乙酰胺在乙腈中及三乙胺存在下反应得到2-甲基-4-三氟甲基-5-噻唑甲酸乙酯4,4经碱水解再酸化得到2-甲基-4-三氟甲基-5-噻唑甲酸1,总收率72.3%,1的结构经IR、MS和1H-NMR的表征。

SO_4^(2-)/TiO_2催化合成乙酸环己酯

以固体超强酸SO24-/TiO2催化乙酸和环乙醇合成了乙酸环己酯。实验确定最佳反应条件为n(乙酸):n(环己醇)=1.0:1.2,SO24-/TiO2用量为乙酸质量的10%,反应时间90min,酯化率达92.3%,并与其它催化剂作了比较,结果表明,以SO42-/TiO2为催化剂,具有催化剂量少、重复使用效果好、反应时间短、酯收率高、方法简单等优点。