5-丁酰胺基-2-(2,3-环氧丙氧基)-苯乙酮的合成

以对丁酰胺基苯酚为原料,经酯化、Fries重排、醚化,合成了醋丁洛尔的关键中间体5-丁酰胺基-2-(2,3-环氧丙氧基)-苯乙酮,收率45.25%。在Fries重排反应中添加惰性无机盐氯化钠为助溶剂,使反应能够顺利进行。     

2-乙酰基-4-正丁酰胺基苯酚的合成工艺改进

以对氨基苯酚为原料．经氨基丁酰化,苯酚乙酸酯化,Fries重排,合成了有内在活性的β1肾上腺素受体阻断药醋丁洛尔的关键中间体2-乙酰基-4-正丁酰胺基苯酚,总收率达56．8％．在关键的Fries重排反应中添加惰性无机盐氯化钠为助溶剂,使反应能够顺利进行。     

(R)-醇腈酶催化法合成光学活性(S)-丁呋洛尔

以7-乙基苯并呋喃-2-甲醛(Ⅰa)为原料,经酶致转氰化、Ritter反应、酰胺还原合成了光学活性(S)-丁呋洛尔(Ⅳa),总产率23.3%,ee值达71%。转氰反应中采用苦杏仁和枇杷仁醇腈酶催化HCN对C O基的加成获得(S)-呋喃氰醇,其中枇杷仁醇腈酶的催化效果更好,反应产率和ee值分别达到54.9%和75%;(S)-呋喃氰醇的O-保护衍生物Ⅱa经醇解反应转化为酰胺化合物Ⅲa,再经LiAlH4还原获得终产物Ⅳa,两步反应产率分别为59%和72%,光学纯度完全保留。利用同样的方法,从苯并呋喃-2-甲醛(Ⅰb)出发,以64.2%的总产率和85%的ee值合成了(S)-丁呋洛尔的结构类似物(S)-2-(叔丁基氨)-1-(苯并呋喃-2-)乙醇。     

N-(9H-芴-9-甲氧羰基氧)丁二酰亚胺合成研究

9-芴甲醇与光气反应合成9-芴甲酯(FMOC-Cl),不经分离直接与N-羟基丁二酰亚胺反应,一锅法合成N-(9H-芴-9-甲氧羰基氧)丁二酰亚胺(FMOC-OSu),总收率95%,产品纯度98%。     

(2R,3S)-3-苄氧羰酰胺基-4-甲基-2-氧代-1-氮杂环丁烷基磺酸钠的合成工艺改进

(2R,3S)-3-苄氧羰酰胺基-4-甲基-2-氧代-1-氮杂环丁烷基磺酸钠是合成氨曲南主环的重要中间体,我们以DMF与三氧化硫络合物取代强腐蚀性的氯磺酸进行磺化-环合反应,在DMAP与2-甲基吡啶复合催化剂的作用下产品收率较原工艺提高了约5%,降低了生产成本。     

(R)-和(S)-硝苯洛尔的不对称催化合成

以4-硝基苯乙酮为原料,经溴化、还原和闭环反应生成外消旋的4-硝基环氧苯乙烷,经手性(R,R)-Salen-Co(Ⅲ)催化剂催化水解动力学拆分(HKR)得到(R)-4-硝基环氧苯乙酮和(S)-1-(4-硝基苯基)-1,2-乙二醇。环氧中间体经异丙胺作用生成(R)-硝苯洛尔,所得到的二醇先与氯化亚砜作用生成环状亚硫酸酯,再与异丙胺反应得到(S)-硝苯洛尔。产物结构经1HNMR、IR、MS表征。     

(3R,4R)-3-[(1′R)-叔丁基二甲基硅氧乙基]-4-乙酰氧基-2-氮杂环丁酮的合成

以化合物(3S,4S)-3-[(1′R)-叔丁基二甲基硅氧乙基]-4-羧基-1-对甲氧基苯基-2-氮杂环丁酮为主要原料,以卟啉锰为催化剂,经氧化脱羧,再由O3氧化脱保护基制得(3R,4R)-3-[(1′R)-叔丁基二甲基硅氧乙基]-4-乙酰氧基-2-氮杂环丁酮(4AA),两步反应总收率达到83.7%.采用卟啉锰做催化剂进行脱羧氧化反应,使该步反应收率达到了93.0%.用FT-IR、1HNMR对最终产物结构进行了表征.     

(S)-4-(甲硫基)-2-[2-羰基-1-吡咯烷基]丁酰胺的合成

(S) 2 氨基 4 (甲硫基)丁酸甲酯盐酸盐于浓氨水中,发生酰胺化反应,制得(S) 2 氨基 4 (甲硫基)丁酰胺,收率63%;(S) 2 氨基 4 (甲硫基)丁酰胺用甲醇溶解,与浓盐酸成盐,得(S) 2 氨基 4 (甲硫基)丁酰胺盐酸盐,收率66%;(S) 2 氨基 4 (甲硫基)丁酰胺盐酸盐在相转移催化剂四丁基溴化铵(TBAB)及研细氢氧化钾的作用下,与4 氯丁酰氯发生取代、环化反应,制得(S) 4 (甲硫基) 2 [2 羰基 1 吡咯烷基]丁酰胺,收率61%。产品的结构经TLC、IR、1HNMR等进行了表征。     

α-乙酰基-γ-丁内酯合成新工艺研究

以γ-丁内酯,乙酸乙酯为原料,金属钠和乙醇钠为催化剂,甲苯为溶剂合成α-乙酰基-γ-丁内酯。在金属钠与乙醇钠的钠摩尔比为7:3,甲苯/γ-丁内酯(w/w)=2.51,反应温度85~90℃,反应时间5h,n(乙酸乙酯):n(GBL):金属钠为2.27:0.9:1的条件下;GBL转化率≥98%,ABL收率≥95%。     

1-(2-羟基乙基)-5-巯基四氮唑的合成研究

以乙醇胺等为原料,经缩合、保护、成环及脱保护反应合成了1-(2-羟基乙基)-5-巯基四氮唑.其中,用醋酐作为中间产物N-(2-羟基乙基)二硫代氨基甲酸甲酯中羟基的保护试剂;用浓盐酸为酸催化剂、丙酮为反应介质,通过控制反应的pH值脱除1-[(2-乙酰基)乙基]-5-巯基四氮唑中的乙酰基.该方法具有收率高(总收率72.0%)、成本低和操作简便等特点.     

Victrex® poly(ethersulfone) (PES) and Victrex® poly(etheretherketone) (PEEK)

Properties of two high performance engineering thermoplastics, amorphous polyethersulfone (PES) and semicrystalline polyetheretherketone (PEEK), are discussed. Both resins can be processed by conventional techniques, compounded with high performance fibers, and have high service temperature (up to 300°C). Due to the amorphous character PES can be dissolved and spray coated into metals.     

Photopyroelectric Spectroscopic Studies of ZnO-MnO(2)-Co(3)O(4)-V(2)O(5) Ceramics

Photopyroelectric (PPE) spectroscopy is a nondestructive tool that is used to study the optical properties of the ceramics (ZnO + 0.4MnO(2) + 0.4Co(3)O(4) + xV(2)O(5)), x = 0-1 mol%. Wavelength of incident light, modulated at 10 Hz, was in the range of 300-800 nm. PPE spectrum with reference to the doping level and sintering temperature is discussed. Optical energy band-gap (E(g)) was 2.11 eV for 0.3 mol% V(2)O(5) at a sintering temperature of 1025 °C as determined from the plot (ρhυ)(2)versushυ. With a further increase in V(2)O(5), the value of E(g) was found to be 2.59 eV. Steepness factor 'σ(A)' and 'σ(B)', which characterize the slope of exponential optical absorption, is discussed with reference to the variation of E(g). XRD, SEM and EDAX are also used for characterization of the ceramic. For this ceramic, the maximum relative density and grain size was observed to be 91.8% and 9.5 μm, respectively.     

(Ba_(1-α)Sr_α)_(4.8)(Sm_(0.7)La_(0.3))_(8.8)Ti_(18)O_(54)陶瓷的微波介电性能

采用固相合成法制备了(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54(α=0.1～0.5)系陶瓷,表征了该陶瓷的相组成和显微结构,测试了微波介电性能.结果表明:α=0.3时,(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54系陶瓷为单相的新钨青铜结构固溶体.α>0.3时,相继出现了第二相BaLa2Ti4O12和La0.66TiO2.993.随α的增加,(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54系陶瓷的相对介电常数(εr)先增大后有所波动,品质因数(Qf)先增大后减小,谐振频率温度系数(τf)单调减小.α=0.3时,在1 350℃烧结的陶瓷的微波介电性能最佳:εr=98.77,Qf=5184GHz,τf=10.9×10-6/℃,优于不掺杂的BaO-Sm2O3-TiO2陶瓷的.     

Calcium silicate hydrate (II) (“C-S-H(II)”)

This semicrystalline phase, originally named ‘calcium silicate hydrate(II)’ by Taylor (1950), has been studied with X-rays, electron optics, chemical investigation of silicate anion type, infrared spectra, and thermal methods. It is structurally related to jennite (C₉S₆H₁₁) and probably also to the fibrous CSH of cement pastes, the three phases forming a sequence of decreasing crystallinity. The specimen studied had approximate composition C₂SH_3.2 after standing over saturated CaCλ₂ at about 15°C. CSH(II) contains metasilicate chains and pyrosilicate groups and has a disordered layer structure. Much of the water can be lost reversibly without significant change in lattice parameters.     

Poly(butadiene-acrylic acid(g)acrylonitrile(g)acrylic acid)

Summary In the present work we describe, the synthesis and characterization of a new gel obtained by crosslinking a cooligomer of butadiene-acrylic acid (BuAA), by reaction with acrylonitrile and acrylic acid. The purified product was characterized by FTIR, elemental analyses and scanning electronic microscopy. The thermal properties were studied and swelling indexes were determined in different solvents and at different pH values. The capacity of poly(butadiene-acrylic acid(g)acrylonitrile(g)acrylic acid) [gel A] to separate different organic substances, such as amino acids and colorants, was determined.     

Thermal studies of blends of poly(phenylene sulfide) (PPS) with poly(phenylene sulfide sulfone) (PPSS) and with poly(phenylene sulfide ether) (PPSE)

The miscibilities of poly(phenylene) sulfide/poly(phenylene sulfide sulfone) (PPS/PPSS) and poly(phenylene) sulfide/poly(phenylene sulfide ether) (PPS/PPSE) blends were invesigated in terms of shifts of glass transition temperatures T_g of pure PPS, PPSS, a dn PPSE. The crystallization kinetics of PPS/PPSS blends was also studied as a function of molar composition. The PPS/PPSS and PPS/PPSE blends are respectively partially and fully miscible. PPSE shows a plasticizing effect on PPS as does PPS on PPSS, which necessarily improves te processibility in the respective systems. We can control T_g and melting temperature T_m of PPS by varying amounts of PPSE in blends. The melt crystallization temperature T_mc of PPS/PPSE blends was higher than that of the PPSE homopolymer. Therefore, these blends require shorter cycle times in processing than pure PPSE. The overall rate of crystallization for PPS/PPSS blends follows the Avrami equation with an exponent ?2. The maximal rate of crystallization for PPS/PPSS blends occurs at a temperatre higher by 10°C than that for PPS, while the crystallization half time t_1/2 is 4 times shorter. In the cold crystallization range, crystal growth rates increase and Avrami exponents decrease significantly as the temperature increases.     

Photooxidative stability of substituted poly(phenylene vinylene) (PPV) and poly(phenylene acetylene) (PPA)

The addition of side groups to improve the photooxidative stability of polymers used in polymer-based light-emitting diodes (LEDs) is explored. Infrared spectroscopy and computational chemistry techniques are used to study the effects of chemical substitution of the reactive vinylene moiety in poly(phenylene vinylene) (PPV). The bond order of the vinylene group in small oligomers is calculated using semiempirical techniques to assess the improvement in stability toward oxidants such as singlet oxygen. We find that PPV dimers allow relative comparisons across a range of possible substitutions. Experimental results correlate well with these calculations. The addition of electron-withdrawing substituents, such as nitrile groups, to the vinylene moiety is found to be particularly effective in reducing the reactivity of alkoxy-substituted PPV toward singlet oxygen. The photooxidative stability of a poly(phenylene acetylene) (PPA) derivative is also studied. It appears that this family of polymers is more stable toward photooxidation than are its PPV analogs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2451–2458, 1998     

Chemical cross-linking of conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) using poly(ethylene oxide) (PEO)

Hybrid films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were prepared with different molecular weights of poly(ethylene oxide) (PEO). The cross-linking reaction between PEO and PEDOT:PSS was performed at high temperature and confirmed by using differential scanning calorimeter (DSC), contact angle measurement, and solid-state ¹H NMR. The effect of chemical reaction on the conductivity and morphology of these hybrid films was studied by using 4-point probe and atomic force microscope (AFM), respectively. As-spun PEO/PEDOT:PSS films have lower electric conductivity due to the addition of nonconductive PEO, and exhibits no molecular weight dependence on conductivity. After chemical cross-linking reaction at high temperature, only PEDOT:PSS films with lowest molecular weight PEO additives show enhanced conductivity with increasing reaction time. AFM result indicates that the heat-treated PEO/PEDOT:PSS hybrid films show grain-like morphology compared to ethylene glycol treated PEDOT:PSS films which shows continuous PEDOT domain. In the present work we demonstrate that the cross-linking reaction can be used to improve the wet stability of PEDOT:PSS nanofiber, showing good water resistance and excellent dimensional stability.