爱德万甜中间体3-羟基-4-甲氧基肉桂醛的合成

3-羟基-4-甲氧基肉桂醛是制备新型的二肽超高甜度甜味剂爱德万甜的重要中间体。目前制备该中间体的主要方法是通过异香兰素与乙醛在强碱存在下进行羟醛缩合反应，但由于乙醛容易发生自缩合反应从而存在反应条件极为苛刻和3-羟基-4-甲氧基肉桂醛收率低等问题，本文以乙酸乙烯作为反应物替代乙醛与异香兰素发生反应合成3-羟基-4-甲氧基肉桂醛，采用单因素实验考察了反应温度、反应时间、NaOH浓度和异香兰素与乙酸乙烯配比对该反应的影响，并在此基础上进行了响应面优化。在优化的反应条件（NaOH浓度4.5mol/L，反应温度10℃，反应时间12h，异香兰素与乙酸乙烯摩尔比1∶2）下，3-羟基-4-甲氧基肉桂醛收率为71.44%±2.21%。为了进一步提高产品收率，探索了添加相转移催化剂对该反应的强化作用，发现PEG-200对强化该反应有显著作用，3-羟基-4-甲氧基肉桂醛收率可达83.12%±2.18%。     

3-(4-氯-5-环戊氧基-2-氟苯基)-4-亚胺基-5-异丙叉基恶唑烷-2-酮的合成

通过 4 氯 5 环戊氧基 2 氟异氰酸苯酯与 2 羟基 3 甲基 3 丁烯腈发生加成环化反应制得除草剂 3 (4 氯 5 环戊氧基 2 氟苯基 ) 4 亚胺基 5 异丙叉基恶唑烷 2 酮。反应分两阶段进行 ,首先在冰水浴中向 2 羟基 3 甲基 3 丁烯腈中滴加 4 氯 5 环戊氧基 2 氟异氰酸苯酯甲苯溶液 ,然后升至室温反应 4h。优化的反应条件为 :三乙胺作催化剂 ,n(4 氯 5 环戊氧基 2 氟异氰酸苯酯 )∶n(2 羟基 3 甲基 3 丁烯腈 ) =1 0∶1 2 ,加料方式为滴加 4 氯 5 环戊氧基 2 氟异氰酸苯酯甲苯溶液 ,第二阶段反应在室温下进行。反应条件优化以后 ,产品收率可由 39%提高到 5 6 %。产品结构用CIMS、1HNMR进行了确定。分离了其中一个副产物 ,并对其结构进行了鉴定。     

4-苄基-2-羟基-吗啉-3-酮的合成

以乙醛酸和N-苄基乙醇胺为原料,合成4-苄基-2-羟基-吗啉-3-酮。通过正交实验考察了反应条件对目标产物收率的影响。结果表明,当原料摩尔比n(乙醛酸)∶n(N-苄基乙醇胺)=2∶1,反应时间22 h,反应溶剂四氢呋喃用量35 mL,反应温度65℃时,目标产物的收率最高可达62%。并进一步考察了反应温度和原料摩尔比对反应收率的影响。     

3,4-二羟基苯腈的合成

以3-甲氧基-4-羟基苯甲醛（香兰素）为原料,经与盐酸羟胺反应得到3甲氧基-4-羟基苯腈,再与碱金属卤化物经脱甲基化反应合成3,4-二羟基苯腈,产品含量99.8%,以香兰素计总收率75.2%。与其他合成方法比较,这条合成路线更适合于工业化。     

由 2-硝基-4-乙酰氨基苯甲醚合成N-(3-氨基-4-甲氧基苯基)乙酰胺

以2-硝基-4-乙酰氨基苯甲醚为原料合成N-(3-氨基-4-甲氧基苯基)乙酰胺,考察了铁粉用量、冰醋酸用量和水量等对N-(3-氨基-4-甲氧基苯基)乙酰胺收率的影响.确定了最佳工艺条件n(2-硝基-4-乙酰氨基苯甲醚)∶n(铁粉)∶n(冰醋酸)∶n(水)=1∶2.4∶0.29∶40.8,反应时间为3 h.此条件下N-(3-氨基-4-甲氧基苯基)乙酰胺的收率达91.9%,纯度达99.9% (HPLC) .     

2-(E)-(取代苯亚甲基)环己酮的合成工艺研究

采用异香兰醛和环己酮为原料,以乙醇为溶剂,在哌啶催化作用下羟醛缩合合成了姜黄素类抗癌药物重要中间体2-(E)-(3-羟基-4-甲氧基苯亚甲基)环己酮,通过1H NMR对产品的结构进行确证。并对反应条件进行了优化,优化条件为n(异香兰醛)∶n(环己酮)=1∶3,催化剂为哌啶,且质量为环己酮质量的20%,常压下70℃混合反应,反应结束后通过干法柱层析纯化,2-(E)-(3-羟基-4-甲氧基苯亚甲基)环己酮的反应收率达60.5%。通过扩展实验可知同样适用于香兰醛、3,4,5-三甲氧基苯甲醛等芳醛。     

2-溴-4-甲氧基-5-[3-(吡咯烷-1-基)丙氧基]苯胺的合成

以4-溴-2-甲氧基苯酚(2a)、1-氯-3-碘丙烷(3)和吡咯烷为原料,通过一锅法反应,合成得到1-[3-(4-溴-2-甲氧基苯氧基)丙基]吡咯烷(4a),再经过硝化、还原两步反应,得到目标化合物2-溴-4-甲氧基-5-[3-(吡咯烷-1-基)丙氧基]苯胺(1)。产物以及中间体结构经~1H NMR和ESI-MS表征。对于每一步反应过程进行了讨论,并以化合物4a的合成为模型反应,重点讨论影响产物收率的因素,确定其最佳反应条件为:反应溶剂为乙腈,n(2a)∶n(3)∶n(吡咯烷)=1.0∶1.2∶2.4,n(K_2CO_3)∶n(2a)=4∶1,n(KI)∶n(2a)=1.5∶1.0,反应温度85℃。该反应条件也被用于1-[3-(2-甲氧基-5-硝基苯氧基)丙基]吡咯烷(4b)的合成。     

3-乙氧基-4-甲氧基苯甲醛的合成

以乙醇为溶剂,以异香兰素和溴乙烷为原料,以碘化钾为催化剂,碳酸钾为缚酸剂,合成3-乙氧基-4-甲氧基苯腈中间体3-乙氧基-4-甲氧基苯甲醛。考察了原料摩尔比、反应体系的压力、反应温度及时间等因素对产品收率的影响。最佳合成工艺条件为:异香兰素45. 6g(0. 30mol),异香兰素与溴乙烷摩尔比为1. 00:1. 15,0. 5MPa下于85℃下反应5h,3-乙氧基-4-甲氧基苯甲醛的收率达到97%以上。     

1-(4-氯苯基)-2-环丙基-1-丙酮合成的改进方法

改进了1-(4-氯苯基)-2-环丙基-1-丙酮的合成方法。以2-(4-氯苯基)-3-环丙基丁腈为原料,在臭氧和氢氧化钠的作用下合成产物,优化条件为:m(水)∶m[2-(4-氯苯基)-3-环丙基丁腈]=12∶1,n(臭氧)∶n[2-(4-氯苯基)-3-环丙基丁腈]=1.6∶1.0,反应温度50℃,臭氧通入和氢氧化钠滴加时间为2 h,优化条件下,收率达80%。     

4-(3′-氯苯氨基)-6-甲氧基喹唑啉类衍生物的合成、表征及抗癌活性研究

以N′-(5-(3-氯丙氧基))-2-氰基-4-甲氧苯基-N,N-二甲基甲脒为原料,经过成环、醚化,合成了4个4-(3′-氯苯氨基)-6-甲氧基喹唑啉类化合物：N-(3′-氯苯基)-6-甲氧基-7-(3-(4-硝基苯氧基)丙氧基)喹唑啉-4-胺、N-(3′-氯苯基)-6-甲氧基-7-(3-(3-硝基苯氧基)丙氧基)喹唑啉-4-胺、4-(3-(4-(3′-氯苯胺基)-6-甲氧基喹唑啉-7-基氧基)丙氧基)-3-甲氧基苯甲醛、3-(3-(4-(3′-氯苯胺基)-6-甲氧基喹唑啉-7-基氧基)丙氧基)-4-甲氧基苯甲醛,收率分别为51.3%、60.3%、85.4%、79.4%。产物的结构经红外光谱、核磁共振氢谱、核磁共振碳谱、质谱和元素分析表征。采用MTT法进行化合物抑制Bcap-37细胞的体外活性测试,结果表明：合成的化合物具有不同程度的抑制Bcap-37细胞的活性, 其中化合物Ιa在10 μmol?L-1浓度下对Bcap-37细胞的抑制率为83.4%。     

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-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-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