分子印迹在线固相萃取分离奥克托今合成反应中间体

采用分子印迹在线固相萃取和液相色谱-质谱联用技术建立了奥克托今合成反应中间体1,3,5,7-四乙酰基-1,3,5,7-四氮杂环辛烷(TAT)与1,3,5-三乙酰基-1,3,5-三氮杂环己烷(TRAT)的分离鉴定方法。固相萃取填料采用TAT分子印迹聚合物,液相色谱分离检测采用亲水色谱柱。首先以乙腈为固相萃取柱上样溶剂,流速为0.1 mL/min,然后以乙酸乙酯淋洗萃取柱,用甲醇洗脱,并以甲醇为流动相对洗脱溶液进行液相色谱分离,与质谱仪联用鉴定各分离组分。在上述条件下,TAT回收率在79％~93％,检出限为1.8 mg/L (3σ),线性范围为6.0~500.0 mg/L,富集倍数400倍。     

β-1,3,5,7-四硝基-1,3,5,7-四氮杂环辛烷热膨胀各向异性的量子化学计算与分子动力学模拟

在303～383 K和NPT系综和COMPASS力场下对β-1,3,5,7-四硝基-1,3,5,7-四氮杂环辛烷（HMX）超晶胞初始结构的分子动力学模拟,得到常压下各温度的晶体平衡构型并发现分子的堆积方式不变;通过线性拟合求算出线膨胀系数与实验值相近,体现出明显的各向异性. 采用密度泛函理论方法对沿各晶轴方向膨胀率变化（100%～105%）的HMX单胞模型进行了总能计算,得到的能量变化率体现各向异性并与热膨胀系数值关联,建立了关联方程. 由此阐释了HMX晶体热膨胀各向异性的本质即特定的分子堆积模式.     

固相萃取-高效液相色谱法测定焦糖色素中副产物2-甲基咪唑、4-甲基咪唑和2-乙酰基-4-(1,2,3,4-四羟基丁基)咪唑

建立了固相萃取法结合高效液相色谱同时检测焦糖色素中2-甲基咪唑(2-Methylimidazole,2-MEI)、4-甲基咪唑(4-Methylimidazole,4-MEI)和2-乙酰基-4-(1,2,3,4-四羟基丁基)咪唑(2-Acetyl-4-(1,2,3,4-tetrahydroxybutyl) imidazole,THI)的方法.样品经加水涡旋提取后,经混合型强阳离子交换固相萃取小柱富集净化,以乙腈-0.05％氨水(10∶90,V/V)为流动相,流速为0.6 mL/min,用反向色谱柱Polaris C18-A(250 mm×4.6 mm,5μm)柱分离,分别在二极管阵列检测器215 nm波长条件下检测焦糖色素中的2-甲基咪唑、4-甲基咪唑和287 nm波长条件下检测2-乙酰基4.(1,2,3,4-四羟基丁基)咪唑的含量.2-甲基咪唑、4-甲基咪唑和2-乙酰基-4-(1,2,3,4-四羟基丁基)咪唑在0.2～ 20 mg/L之间线性关系良好(r＞0.9996),在10,25和100 mg/kg添加浓度的回收率范围为75.3％ ～93.4％,相对标准偏差均小于10％,检出限分别为为2.6,3.0和1.5 mg/kg,定量限分别为8.5,10.0和5.0 mg/kg.     

1,3,5,7-四异氰氧基乙基-1,3,5,7-四甲基环四硅氧烷合成及结构表征

以丙烯酸和1,3,5,7-四甲基环四硅氧烷(D4H)等为初始原料,经酯化、硅氢加成反应制得1,3,5,7-四(三甲基硅氧羰丙基)-1,3,5,7-四甲基环四硅氧烷(2),水解2制得1,3,5,7-四羧丙基-1,3,5,7-四甲基环四硅氧烷(3),3经Staudinger反应和Curtius重排反应制得1,3,5,7-四异氰氧基乙基-1,3,5,7-四甲基环四硅氧烷(4).反应总收率为14.5%,化合物结构经1H NMR,29Si NMR,IR,MS和HRMS确证.     

柱前衍生高效液相色谱法分离分析1-氮杂双环[2,2,2]辛-3-基胺对映异构体

1-氮杂双环[2,2,2]辛-3-基胺是制备5-羟色胺拮抗剂药物盐酸帕洛诺司琼等的重要中间体,手性帕洛诺司琼可以通过中间体的手性分离来制备。用柱前衍生化-反相高效液相色谱法对1-氮杂双环[2,2,2]辛-3-基胺对映体进行分离并建立了检测方法。结果表明,用2,3,4,6-四-O-乙酰基-β-D-葡萄糖异硫氰酸酯(GITC)为柱前手性衍生化试剂,C18柱(300mm×4.6mm,5μm)为色谱柱,可将1-氮杂双环[2,2,2]辛-3-基胺对映体分离,其它色谱条件:流动相组成为[甲醇-乙腈-0.01mol/L四丁基溴化铵(20∶10∶75,V/V)]-(三乙胺)0·1%-(冰醋酸)0.15%,流速0.7mL/min,检测波长为266nm。在选择的测定条件下,衍生后的两非对映异构体分离度达4以上。     

1,3,5,7-四甲基氟硼二吡咯甲川的合成、晶体结构及密度泛函理论研究

以2,4-二甲基吡咯、原甲酸三乙酯以及对甲苯磺酸为原料,无溶剂下合成了1,3,5,7-四甲基对甲苯磺酸二吡咯甲川(T1);以T1、三氟化硼乙醚以及三乙胺为原料,无溶剂下合成了1,3,5,7-四甲基氟硼二吡咯甲川(F1)。利用1H NMR和X射线单晶衍射对其进行了表征。结果表明:T1属于单斜晶系,P21/c空间群,晶胞参数为a=0.777 3(3)nm,b=1.518 5(5)nm,c=1.612 2(5)nm,β=91.923(12)°,V=1.901 9(11)nm3,Z=4;F1属于单斜晶系,P21/n空间群,晶胞参数为a=0.775 02(1)nm,b=1.444 20(3)nm,c=1.174 35(2)nm,β=107.779 5(9)°,V=1.251 65(4)nm~3,Z=4。在4种不同溶剂中,测定了T1的紫外可见光谱、F1的紫外可见光谱和稳态荧光光谱。将密度泛函计算与前线轨道理论相结合,研究了T1和F1可能的衍生方式。     

高效液相色谱检测反应香精中的2-氨基-N-甲基-5-苯基咪唑并吡啶(PhIP)方法研究

建立了用高效液相色谱快速检测反应香精中2-氨基-N-甲基-5-苯基咪唑并吡啶的方法. 反应香精中的2-氨基-N-甲基-5-苯基咪唑并吡啶用二甲基甲酰胺直接超声振荡提取; 高效液相色谱的色谱柱为Eclipse XDB-C18 (250 mm×4.6 mm, 5 μm); 流动相为V(二甲基甲酰胺)∶V(甲醇)∶V(水)=8∶50∶42; 流速为0.5 mL/min; 光电二极管阵列检测器检测波长为UV-327 nm. 10种反应香精中均未检出该种物质, 回收率为78.9%～85.9%, 检出限为19.2 ng/mL.     

3,7-二亚氨基-2,6-二硫杂-4,8-二氮杂双环[3,3,0]辛烷及其衍生物的合成

本文报导了3,7-二亚氨基-2,6-二硫杂-4,8-二氮杂双环[3,3,0]辛烷(5)及其衍生物四硝基(4),四乙酰基(7),二乙酰基(8)和苦味酸盐(6)的制备。(7)易失去两个乙酰基而得到二乙酰基衍生物(8),(8)还可以再乙酰化而重新得到(7)。(7)用Raney镍脱硫而得到一个直链四乙酰含氮化合物(9)。通过上述反应和有关化合物的元素分析、红外光谱、~1H核磁共振、质谱等确证了上述化合物的化学结构。     

含能材料HMX-RDX的热行为研究

采用差示扫描量热法研究了含能材料1,3,5,7-四硝基-1,3,5,7-四氮杂环辛烷-环三甲撑三硝胺(HMX-RDX)的热行为。结果表明,当m(HMX)∶m(RDX)=25∶75时HMX和RDX达到了共熔。随着RDX含量的增加,HMX-RDX的晶型转变温度有所升高,晶型转化的热焓逐渐减少,共熔热焓却随之增加,共熔温度基本保持不变。     

RP-HPLC测定反式-2-硝基乙烯基噻吩的含量

建立了反相高效液相色谱测定反式-2-硝基乙烯基噻吩含量的方法.采用shim-pack C18柱(5 μm,4.6 mm i.d.×250 mm),流动相为V(乙腈)∶V(pH 3的KH2PO4水溶液)=50∶50,流速为1.0 mL/min,检测波长为210 nm.外标法定量,反式-2-硝基乙烯基噻吩在0.002～0.1 mg/mL浓度范围内呈良好的线性关系,线性回归系数(r)为0.9998,平均回收率为99.80%,RSD=0.67% (n=9).     

15N Studies of the Mechanisms of Nitration of Hexamethylenetetramine and 3,7-Diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane

Mechanistic studies of the nitration of hexamathylanetetramine (1) and some derivatives are reported and are compared with acetylation reactions. Nitration reactions, with nitric acid, were carried out using mixtures of [¹⁵N₄]- and [¹⁴N₄]-compounds and the destination of the nitrogen-isotopes in the products was determined mass spectrometrically. The results show that in nitration of (1) to give 3,7-dinitro-l,3,5,7-tetraazablcyclo[3.3.1]nonane (DPT) extensive ring cleavage occurs to give species containing single amino-nitrogen fragments. However the nitration of 3,7-diacetyl-1,3,5,7-tetraazabicyclo(3.3.1]nonane (DAPT) to 1,5-diacetyl-3,7-dinitro-1,3,5,7-tetraazacyclooctane (DADN) involves selective cleavage of the methylene bridge. A synthesis of DADN by acetolysis of DPT is reported.     

Struktur von S-9,10-Dimethyl-1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantan und 9,10-Diethyl-1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantan

Structure of S-9,10-Dimethyl-1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantane and 9,10-Diethyl-1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantane S-9,10-Dimethyl-1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantane ( 1 ) and 9,10-diethyl-1,3,5,7-tetraarsa-2,4,6,8-tetraoxaadamantane ( 2 ) have been prepared by the reaction of propionic acid, propionic anhydride and butyric acid, butyric anhydride, respectively, with arsenic(III)-oxide. The crystals of 1 are rhombic, a = 6.902(4), b = 11.121(5), c = 13.988(8), space group P2₁2₁2₁. The crystals of 2 are monoclinic, a = 11.757(10), b = 11.255(10), c = 18.631 (18), β = 91.78(7), space group P2₁/n. The mean bond lengths and angles in 1 are AsO = 1.790 Å, AsC = 1.959 Å, OAsO = 100.60°, CAsO = 99.65°, AsOAs = 128.77°, AsCAs = 118.73°, and in 2 they are AsO = 1.780 Å, AsC = 1.978 Å, OAsO = 101.45°, CAsO = 99.55°, AsOAs = 129.64°, AsCAs = 117.72°.     

Nitrogen-15 studies of the mechanisms of acetolyses of hexamethylenetetramine and 3,7-diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DAPT)

[¹⁵N₄]-Hexamethylenetetramine (Hexamine), and [¹⁵N₄]-3,7-diacetyl-1,3,5,7-tetraazabicyclo[3.3.1]nonane(DAPT) have been prepared starting from ¹⁵NH₃. Synthetic acetolysis reactions were performed using mixtures of pure [¹⁵N₄]- and [¹⁴N₄]-compounds and the destination of the nitrogen isotopes in the products was determined mass spectrometrically. The results show that relatively little isotopic mixing occurs in the acetolysis of hexamine to DAPT though the formation of some products with isotopic composition [¹⁴N₃¹⁵N₁] and [¹⁴N₁¹⁵N₃] indicates limited ring cleavage. However the more severe conditions used in the formation of 1,3,5-triacetyl-1,3,5-triazacyclohexane (TRAT) give rise to considerable isotopic scrambling. The acetolysis of DAPT to give 1,3,5,7-tetraacetyl-1,3,5,7-tetraazacyclooctane occurs by selective cleavage of the methylene bridge.     

The surface properties of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane after partial solution in nitro esters

The thermophysical properties and surface structure of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (TNCO) particles before and after their contact with liquid nitro esters were studied by differential scanning calorimetry and small-angle X-ray scattering. The thermophysical properties of TNCO changed after contact with nitro esters, and the temperature range of the transition from the β to δ polymorph broadened. This peculiarity was explained in terms of the fracton theory by changes in the heat capacity of particles related to the formation of nanoscale roughness with a fractal (scale-invariant) organization as a result of surface etching by solvents such as nitro esters, which are thermodynamically “bad” with respect to TNCO. The volume properties of particles did not change. The possibility of determining the fractal dimension of the surface of TNCO particles by differential scanning calorimetry was demonstrated. The rate of heating was then used as a “scale ruler” (“yardstick”), and the temperature range of the transition from the β to δ polymorph, as a measured parameter. The dimension of the surface fractal was also determined by an independent method (small-angle X-ray scattering). The results obtained by the two methods were closely similar.     

1,3,5,7-四甲基-8-丙酰肼-二氟化硼-二吡咯甲烷柱前衍生高效液相色谱测定白酒中的脂肪醛

以合成的1,3,5,7-四甲基-8-丙酰肼-二氟化硼-二吡咯甲烷(BODIPY-丙酰肼)作为柱前荧光衍生试剂,用于高效液相色谱分离荧光法检测甲醛、乙醛、丙醛、丁醛、戊醛、己醛、庚醛、辛醛、壬醛、癸醛、十一醛、十二醛等12种脂肪醛.通过对衍生条件和分离条件进行优化,建立了测定脂肪醛的HPLC/FD新方法.衍生反应以H3P...     

Separation of 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane and 1,3,5‐trinitro‐1,3,5‐ triazacyclohexane by molecularly imprinted solid‐phase extraction

Synthesis of 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane and 1,3,5‐trinitro‐1,3,5‐triazacyclohexane by the Bachmann process leads to a mixture of both. The separation of 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane and 1,3,5‐trinitro‐1,3,5‐triazacyclohexane from their mixture is difficult because the sizes and physical properties of these homologous compounds are similar. For this purpose, seven molecularly imprinted polymers have been synthesized for each explosive, and a selective solid‐phase extraction procedure has been developed. A molecularly imprinted polymer, synthesized with 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane as the template, methacrylic acid as the monomer and trimethylolpropane trimethacrylate as the cross‐linking agent in a molar ratio of 1:8:8 showed the best separation capability. A packed cartridge containing this polymer can be reused for 23 solid‐phase extraction cycles without repacking, and the total separation capability toward 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane reached 6.81 mg per gram of polymer. 1,3,5‐Trinitro‐1,3,5‐triazacyclohexane was not detected in the separated 1,3,5,7‐tetranitro‐1,3,5,7‐tetraazacyclooctane by high‐performance liquid chromatography and vice versa. This newly developed method had the advantages of high recovery (100%) and purity, environmental friendliness, and room temperature operability. This study showed that some molecularly imprinted polymers that cannot absorb target analytes well in the solvent in which the polymers were polymerized might have high‐binding capacity for the analytes and show imprinting effects in other solvents.     

液相色谱-质谱法测定人体血浆中非那雄胺含量

建立了测定人体血浆中非那雄胺药物浓度的液相色谱-质谱分析方法。色谱柱为Hypersil-Keystone C_(18)柱,流动相为乙腈∶水(含0.2%三氯乙酸)=55∶45(V/V),质谱选择电喷雾正离子源(ESI+),选择离子模式(SIM)监测,非那雄胺和内标卡马西平质荷比分别为m/z373和m/z237。血浆样品经乙腈去蛋白、离心和吹干后,残渣用流动相溶解。当非那雄胺的浓度在0.5~120ng·mL~(-1)范围时线性关系良好(r=0.999),检测限(S/N=3)为0.02ng·mL~(-1);日间和日内测定的精密度(RSD)分别在6.4%~2.2%和5.5%~1.7%之间;加标0.5ng·mL~(-1)、40ng·mL~(-1)和80ng·mL~(-1)非那雄胺的平均回收率(n=6)分别为108.5%、101.2%和98.7%。方法快速、准确和灵敏,已成功用于人血浆中非那雄胺浓度的测定和人体药代动力学研究。     

Ultra-trace level determination of nitrite in human saliva by spectrofluorimetry using 1,3,5,7-tetramethyl-8-(3,4-diaminophenyl)-difluoroboradiaza-s-indacene

A rapid, highly sensitive and selective fluorogenic method for the determination of traces of nitrite is described. It is based on the reaction of weakly fluorescent 1,3,5,7-tetramethyl-8-(3,4-diaminophenyl)-difluoroboradiaza-s-indacence (DAMBO) and nitrite in acidic aqueous solution to give 1,3,5,7-tetramethyl-8-(5-benzotriazolyl)-difluoroboradiaza-s-indacene (DAMBO-T), which is highly fluorescent. The optimum reaction conditions and other analytical parameters are investigated to enhance the sensitivity of the method. The fluorescence enhancement at 507 nm is linearly related to the concentration of nitrite in the range of 6.0 × 10⁻⁹–5.0 × 10⁻⁷ mol L⁻¹ with a correlation coefficient of R = 0.9995 (n = 10) and a detection limit of 1.0 × 10⁻¹⁰ mol L⁻¹. The R.S.D. is 1.12% (n = 10). The method is applied to the determination of nitrite in human saliva samples with the recoveries of 96. 24–105.30%. Correspondence: Ke-Jing Huang, Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China     

酸催化甘油与苯甲醛缩合制备六员环缩醛

比较了对甲苯磺酸（PTSA）、磷钨酸（PWA）、KHSO₄和FeCl₃催化对甘油与苯甲醛的缩合反应收率,及对产物中六元环缩醛5-羟基-2-苯基-1,3-二氧六环(1)与五元环缩醛4-羟甲基-2-苯基-1,3-二氧五环(2)比例的影响。 当以环己烷为带水剂及苯甲醛与甘油的摩尔比为2∶3的情况下,KHSO4为催化剂的缩合产物（1+2）收率较高,为96.8%;PTSA催化的缩合产物中,化合物1的比例最高(m(1)∶m(2)=48.6∶51.4)。 室温下PTSA、PWA、KHSO₄和FeCl₃均可催化化合物2向化合物1的转化。 在-20 ℃下,只有PTSA能催化化合物2向化合物1的转化。 在-20 ℃,PTSA催化化合物[STHZ]2转化成化合物1a,并以晶体形式从苯（40%）-石油醚（60%）中析出。 母液循环转化3次后,化合物1a的累计收率可达91.1%。     

Pd-Cu/ZrO2催化CO2加氢制甲醇的性能

采用溶胶-凝胶法制备了n(Cu):n(Zr)=1:1、1:2、1:4和1:8的Cu/ZrO₂催化剂。 实验结果表明,当n(Cu):n(Zr)=1:4时,催化剂表现出较高的CO₂转化率(8.0%)和甲醇选择性(59.5%),为了增加CO₂的转化率,提高甲醇选择性,在n(Cu):n(Zr)=1:4的催化剂中添加质量分数1%的Pd,采用浸渍法制备了Pd-Cu/ZrO₂催化剂。 在250 ℃、2 MPa、12000 mL/(g·h)和V(H₂):V(CO₂)=3:1的反应条件下,CO₂转化率和CH₃OH收率相比Cu/ZrO₂催化剂(n(Cu):n(Zr)=1:4)分别提高了40.0%和80.9%。 通过X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、N₂吸附-脱附(BET)、X射线光电子能谱仪(XPS)和程序升温还原化学吸附仪(H₂-TPR)等仪器表征证明Pd的添加提高了催化剂的分散性和比表面积。 催化剂中Pd和Cu之间强相互作用,使Cu2p轨道结合能向低处偏移,还原温度的降低,说明Pd-Cu/ZrO₂催化剂还原能力增强,使得CO₂加氢活性提高。