5-丙氧基-4-甲基-1,2,4-三唑啉酮的合成

5-丙氧基-4-甲基-1,2,4-三唑啉酮是新型磺酰脲类除草剂——丙苯磺隆的关键中间体。以氯甲酸乙酯和硫氰化钠为起始原料,常温反应得到中间体化合物Ⅰ,然后将其与硫酸二甲酯反应得到中间体化合物Ⅱ,再经水合肼环化得到中间体化合物Ⅲ,最后经硫酸二甲酯甲基化后得到目标化合物Ⅳ。以上各步收率适中。中间产物及目标产物的结构经过熔点1、HNMR和MS表征。该法具有成本低、工业化生产相对安全、易操作的优点。     

1-甲基-3,5-二氯-4-吡唑甲酸甲酯的合成

1-甲基-3,5-二氯-4-吡唑甲酸甲酯是合成磺酰脲类除草剂氯吡嘧磺隆的关键中间体.为了简化工艺条件,降低生产成本,报道了新的合成方法.以三氯乙腈和氰基乙酸甲酯为起始原料,常温反应得到中间体2-氰基-3-氨基-4,4,4-三氯-2-丁烯酸甲酯(Ⅰ),然后将其与水合肼环化得到中间体3,5-二氨基-4-吡唑甲酸甲酯(Ⅱ),再经重氮化氯化得到中间体3,5-二氯-4-吡唑甲酸甲酯(Ⅲ),最后经硫酸二甲酯甲基化后得到目标化合物(Ⅳ).以上缩合、环化、重氮化和甲基化的收率均在85%～90%之间.中问产物及目标产物的结构经过熔点、IR、HNMR和MS表征得以证实.在实验室小试的基础上进行了中试,目标产物的收率与小试结果一致.     

4,6-二甲基-2-甲磺酰基嘧啶的安全合成

以乙酰丙酮为起始原料,经过环化、甲基化和氧化反应3步合成了4,6-二甲基-2-甲磺酰基嘧啶,总收率61.23％.最后一步氧化,使用oxone氧化剂,反应安全高效.中间体及目标分子结构经核磁共振、红外光谱、质谱、熔点测定确证.     

双环磺草酮的合成研究

双环磺草酮是由史迪士生物科学株式会社开发的三酮类对羟基丙酮酸双氧化酶(HPPD)除草剂。笔者以2-氯-4-甲磺酰基苯甲酸为起始原料,经5步反应合成了双环磺草酮,目标化合物的结构经1H NMR和MS确证。同时,笔者对双环磺草酮关键步骤的反应参数进行了系统优化,并对烯醇酯中间体的重排机理进行了探讨。     

2-甲基-5-(4-甲氧基苯磺酰胺)萘并[1,2-b]呋喃-3-羧酸乙酯的合成

乙酰乙酸乙酯与对甲苯胺、磷酸二氢钾反应得到3-(对甲苯氨基)-2-丁烯酸乙酯(化合物3);4-氨基-1-萘酚盐酸盐与甲氧基苯磺酰氯反应得到4-甲氧基-N-(4-羟基萘)苯磺酰胺(化合物6),之后经高碘酸钠氧化得到4-甲氧基-N-(4-氧代萘)苯磺酰胺(化合物7);中间体3和7发生环化得到目标物2-甲基-5-(4-甲氧基苯磺酰胺)萘并[1,2-b]呋喃-3-羧酸乙酯(化合物8),其结构经1H NMR、13C NMR和HRMS确证.对中间体3、中间体7以及目标物8的合成条件进行优化,滴加原料对甲苯胺、使用KH2PO4作为催化剂时,可在较低温度下顺利得到中间体3;控制氧化剂用量、使用乙醇含量高的水溶液作为溶剂有利于中间体7的生成和后处理;在反应体系中加入少量水,可减少化合物8的副产物生成.该方法为N-(萘并[1,2-b]呋喃-5-基)苯磺酰胺类化合物的合成提供了参考.     

2-氨磺酰基-4-甲磺酰氨基甲基苯甲酸甲酯的合成

[目的]甲磺胺磺隆是一种高效、广谱、低毒、高选择性的磺酰脲类除草剂。综述甲磺胺磺隆重要中间体2-氨磺酰基-4-甲磺酰氨基甲基苯甲酸甲酯的合成方法,并对其中一种合成路线进行详细的研究。[方法]以对甲苯腈为起始原料,经过硝化、氧化、酯化、加氢、磺酰化、重氮化和氨化7步反应得到产物。[结果]在优化的反应条件下,以对甲苯腈计总收率可达31.3%。[结论]该工艺路线具有反应条件温和、产品纯度高、易于实现工业化生产等特点。     

磺草酮的绿色合成研究

以2-氯-4-甲砜基苯甲酸为起始原料,经过酰化、缩合和重排3步反应,合成了玉米田高效除草剂磺草酮。对于中间体1,3-环己二酮的合成,也进行了一定的研究。选取了一条绿色的合成路线,对各步反应进行了优化,提高了反应收率。反应总收率在85．6％以上,含量达98．3％。     

N,N′-双(对甲苯磺酰基)-2-哌嗪羧酸甲酯的合成

由乙二胺和对甲苯磺酰氯反应制得N,N′-双(对甲苯磺酰基)乙二胺。此步最佳工艺条件为:n(对甲苯磺酰氯)∶n(乙二胺)=2.2∶1,反应溶剂为苯,反应温度为40～45℃,反应时间为6h,收率80%。由丙烯酸甲酯和溴反应制得α,β-二溴丙酸甲酯,收率为88%。再由上述二种中间体反应合成标题化合物,此步省略了N,N′-双(对甲苯磺酰基)乙二胺的二钠盐制备,收率为73%。     

2-(4-氨基-4-甲基戊基)丙二酸二甲酯的合成与表征

标题化合物是一种新结构的合成7,7-二甲基吖庚环-2-酮的中间体,该文报道其合成方法及表征。以丙烯酸甲酯和2-硝基丙烷为原料,经过Michael加成反应、酯水解反应、缩合反应、羰基还原反应、酯交换反应以及硝基还原反应,合成得到目标化合物。6步反应总产率达到40%。产物及中间体结构经~1HNMR、~(13)CNMR、FT-IR、元素分析及MS表征。其中,Michael加成产物4-甲基-4-硝基戊酸的结构进一步通过X-单晶衍射确定。并对每一步反应条件进行了简单讨论。该研究为吖庚环-2-酮类化合物的合成提供了一种新颖的中间体结构。     

2-二氟甲基-5-氟苯硼酸的合成

以2-溴-4-氟苯甲醛为起始原料,经过二氟甲基化、硼酸基团取代溴两步反应制备重要有机中间体即标题化合物。目前此化合物的合成方法未见国内外文献报道,且该合成方法原料易得、成本低廉,反应总收率接近80%。     

Ferroelectric Ceramics in the PbMg1/3Nb2/3O3-PbCd1/3Nb2/3O3 System

Solid solutions (1-x)PbMg_1/3Nb_2/3O₃ + xPbCd_1/3Nb_2/3O₃ with x = 0-0.30 are investigated with purpose to work out a capacitor ceramics with good dielectric properties and low sintering temperature. It is found that the perovskite phase forms at sintering near to 980°C and begins to decompose at higher temperatures. When x grows from 0 to 0.30, the Curie temperature linearly grows from -10°C to +25°C, the dielectric permittivity ε_m in the Curie point T_C decreases from 18000 to 6800 and the phase transition becomes more diffused. The dielectric permittivity at room temperature is rather high and the temperature stability is improved. The system is of interest, because it can serve as a base for working out some ceramic materials for capacitors with low sintering temperature, which needs of no special atmosphere at burning.     

3-叠氮甲基-3-甲基氧丁环的合成

以三羟甲基乙烷与碳酸二乙酯为原料,经环化反应合成了3-羟甲基-3-甲基氧丁环(HMM O)。在低温下,HMM O与对甲苯磺酰氯反应生成3-磺酸酯甲基-3-甲基氧丁环(M TM O)。M TM O和叠氮化钠发生叠氮化反应形成叠氮单体3-叠氮甲基-3-甲基氧丁环(AMM O)。三步反应收率分别为76%,96%,85%。用核磁、红外、元素分析和DSC表征了化合物的结构与性能。结构鉴定表明为目标化合物AMM O。     

3-溴甲基-3-甲基氧杂环丁烷的合成

以2,2-二溴甲基丙醇（BBMP）为初始原料,通过与碱发生关环反应生成3-溴甲基-3-甲基氧杂环丁烷（BrMMO）。讨论了碱的种类和用量对BBMP关环产率的影响以及反应体系中碱的浓度、反应温度和反应时间对合成BrMMO产率的影响。通过实验确定的最佳工艺条件为：BBMP与NaOH摩尔比为1.0∶1.1,NaOH醇溶液的质量分数为12%,反应温度为78℃,反应时间为4h时,BrMMO产率为65%。最终产品经元素分析、IR和1HNMR检测确定为BrMMO。该试验工艺简单,原料易得,且溶剂便于回收、污染小。     

3-溴甲基-3-甲基氧杂环丁烷的合成

以2,2-二溴甲基丙醇(BBMP)为初始原料,通过与碱发生关环反应生成3-溴甲基-3-甲基氧杂环丁烷(BrMMO).讨论了碱的种类和用量对BBMP关环产率的影响以及反应体系中碱的浓度、反应温度和反应时间对合成BrMMO产率的影响.通过实验确定的最佳工艺条件为:BBMP与NaOH摩尔比为1.0∶1.1,NaOH醇溶液的质量分数为12%,反应温度为78℃,反应时间为4 h时,BrMMO产率为65%.最终产品经元素分析、IR和1HNMR检测确定为BrMMO.该试验工艺简单,原料易得,且溶剂便于回收、污染小.     

The Preparation and Crystal Structure of TlMnCl3, TlFeCl3, TlCoCl3 and TlNiCl3

The compounds TlMnCl₃, TlFeCl₃, TlCoCl₃ and TlNiCl₃ were prepared by heating T1C1 with the corresponding transition metal dichloride in an evacuated ampoule. Atomic positions were determined from powder photographs. All four compounds were found to be related to the perovskite type structure. TlMnCl₃ has a cubic structure, space group Pm3m, with a_o = 5.025 Å. The other three compounds are hexagonal, probable space group P6₃mc, with cell dimensions (in Å) a₀ = 6.976 and c₀ = 6.008 for the Fe compound, a₀ = 6.907 and c₀ = 5.981 for the Co compound and a₀ = 6.863 and c₀ = 5.881 for the Ni compound. The three hexagonal compounds are isomorphous. A measureable concentration of basal plane stacking faults was found to occur in TlFeCl₃ and also, to a lesser degree, in TlCoCl_3.     

Tunable color emission in LaScO3:Bi3+,Tb3+,Eu3+ phosphor

LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ (x = 0 − 0.04, y = 0 − 0.05, z = 0 − 0.05) phosphors were prepared via high-temperature solid-state reaction. Phase identification and crystal structures of the LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors were investigated by X-ray diffraction (XRD). Crystal structure of phosphors was analyzed by Rietveld refinement and transmission electron microscopy (TEM). The luminescent performance of these trichromatic phosphors is investigated by diffuse reflection spectra and photoluminescence. The phenomenon of energy transfer from Bi³⁺ and Tb³⁺ to Eu³⁺ in LaScO₃:xBi³⁺,yTb³⁺,zEu³⁺ phosphors was investigated. By changing the ratio of x, y, and z, trichromatic can be obtained in the LaScO₃ host, including red, green, and blue emission with peak centered at 613, 544, and 428 nm, respectively. Therefore, two kinds of white light-emitting phosphors were obtained, LaScO₃:0.02Bi³⁺,0.05Tb³⁺,zEu³⁺ and LaScO₃:0.02Bi³⁺,0.03Eu³⁺,yTb³⁺. The energy transfer was characterized by decay times of the LaScO₃:xBi³⁺, yTb³⁺, zEu³⁺ phosphors. Moreover absolute internal QY and CIE chromatic coordinates are shown. The potential optical thermometry application of LaScO₃:Bi³⁺,Eu³⁺ was based on the temperature sensitivity of the fluorescence intensity ratio (FIR). The maximum S_a and S_r are 0.118 K⁻¹ (at 473.15 K) and 0.795% K⁻¹ (at 448.15 K), respectively. Hence, the LaScO₃:Bi³⁺,Eu³⁺ phosphor is a good material for optical temperature sensing.     

2,2,3-三氯-3-苯基-3-(3-甲基苯甲酰基)丙腈的合成研究

以苯甲酰氯、四氯化碳、间甲基苯甲酰氰为原料,合成了标题化合物。重点考察了氰化过程中不同原料配比、反应温度、时间、溶剂和催化剂用量对收率的影响。实验结果表明,其最佳反应条件为:n(1,1,2-三氯-2-苯基乙烯)∶n(3-甲基苯甲酰氰)=1∶1.2,二氯甲烷为反应溶剂,3 mmol催化剂三乙胺,室温反应5 h,总收率达80.6%。     

Thermal analyses of poly(3-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

Thermal analyses of poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(HB–HV)], and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(HB–HHx)] were made with thermogravimetry and differential scanning calorimetry (DSC). In the thermal degradation of PHB, the onset of weight loss occurred at the temperature (°C) given by T_o = 0.75B + 311, where B represents the heating rate (°C/min). The temperature at which the weight-loss rate was at a maximum was T_p = 0.91B + 320, and the temperature at which degradation was completed was T_f = 1.00B + 325. In the thermal degradation of P(HB–HV) (70:30), T_o = 0.96B + 308, T_p = 0.99B + 320, and T_f = 1.09B + 325. In the thermal degradation of P(HB–HHx) (85:15), T_o = 1.11B + 305, T_p = 1.10B + 319, and T_f = 1.16B + 325. The derivative thermogravimetry curves of PHB, P(HB–HV), and P(HB–HHx) confirmed only one weight-loss step change. The incorporation of 30 mol % 3-hydroxyvalerate (HV) and 15 mol % 3-hydroxyhexanoate (HHx) components into the polyester increased the various thermal temperatures T_o, T_p, and T_f relative to those of PHB by 3–12°C (measured at B = 40°C/min). DSC measurements showed that the incorporation of HV and HHx decreased the melting temperature relative to that of PHB by 70°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 90–98, 2001