光化学合成α-溴代邻硝基乙苯的研究

以乙苯为原料经硝化制得邻硝基乙苯,然后通过光化学反应进行溴代合成了光致保护剂α-溴代邻硝基乙苯。最佳反应条件为①硝化反应：温度25～30℃,反应时间2 h,邻硝基乙苯收率为32%；②光化学溴化反应：邻硝基乙苯/溴(摩尔比)=2：1,光照时间大于1 h,α-溴代邻硝基乙苯收率大于95%。利用~1H NMR对其结构进行了验证。     

溴素法α-溴代间氯苯丙酮合成研究

在金属卤化物催化剂 HD2 0 0 1存在下 ,溴与间氯苯丙酮在乙酸中反应得到盐酸安非他酮中间体 α-溴代间氯苯丙酮。最佳反应条件是 :n(间氯苯丙酮 )∶n(溴 ) =1∶ 1 ,催化剂用量为 1 %(质量分数 ) ,溴滴加时间为 1 h,反应温度为 1 0°C,此条件下 ,产物纯度为 98.83%,收率为 96.1 %。     

Rheological properties and compatibility of NR/EPDM and NR/brominated EPDM blends

Ethylene–propylene–diene terpolymer (EPDM) was modified by bromination reaction. Blending the resulting brominated EPDM with natural rubber (STR5L) and blending the unmodified EPDM with STR5L at various compositions were carried out. The rheological properties of the blends were investigated using a capillary extrusion. Shear flow curves of the pure rubbers and their blends illustrated the pseudoplastic property as shear thinning behavior with a power law index n < 1. True shear viscosity of all blends showed the negative deviation in relation to their additive values. Rheological behavior and two T_g's found from the DSC thermograms at all blend compositions indicated blend incompatibility for both sets of blends. The incompatibility of the vulcanized blends was also found by measuring the spin–spin relaxation time T₂ by pulsed NMR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 837–847, 2003     

对溴甲基苯腈的合成及精制工艺研究

以对甲苯腈和溴素为原料经光照溴化制得对溴甲基苯腈,产品经溶剂洗涤、混合溶剂重结晶等过程进行精制。通过对反应的考察,得到最佳合成工艺条件为n(对甲苯腈)∶n(溴素)=1∶1.1,反应温度145~150℃。产品精制选择乙醇为洗涤溶剂,乙醇与乙酸乙酯组成的混合溶剂作为重结晶溶剂,其中V(乙醇)∶V(乙酸乙酯)=3∶1,采用IR和MS对产品进行定性分析,经GC分析,产品纯度达99%以上,总收率为68.6%。     

Head-to-head polymers: 33. Bromination of cis-1,4-polybutadiene to head-to-head poly(vinyl bromide)

Cis-1,4-polybutadiene (PB) in a 0.5% solution of a solvent mixture of dichloromethane and 1,2-dibromoethane or tetrahydrofuran was quantitatively brominated with elemental bromine at 0°C under careful exclusion of oxygen to head-to-head poly(vinyl bromide). Partially brominated PB has a structure of random or block sequences of butadiene units in the polymer depending on the bromination solvent but shows no stereospecificity in the CHBrCHBr-dyads. Partially brominated PB with block structure showed a microphase-separated morphology over a wide range of composition. Microphase separation is less pronounced for the more random structure of butadiene units. I.r and ¹³C n.m.r. spectroscopy of the partially brominated PB was used to follow the progress of the bromination.     

Commercial synthesis of α-D-cellobiosyl bromide heptaacetate

A detailed commercial process for the synthesis and purification of the activated disaccharide, α-D -cellobiosyl bromide heptaacetate ( 1 ) was developed. Reaction of α-D -cellobiose octaacetate (CBO) with HBr in glacial acetic acid or in glacial acetic acid/methylene chloride combination affords α-D -cellobiosyl bromide heptaacetate in high yield and excellent quality. Process variables such as reaction solvent, reaction time, reaction temperature, HBr stoichiometry, isolation methods and product purification options were optimized for large-scale synthesis. α-D -Cellobiosyl bromide heptaacetate was successfully prepared in a commercial manufacturing plant.     

香兰素合成新工艺研究

研究了以对甲酚、溴和过氧化氢等主要原料,经过溴化、甲氧基化和氧化反应合成香兰素的工艺。０．６ｍｏｌ溴和１．０ｍｏｌ过氧化氢在１０℃,４ｈ内滴加到１．５ｍｏｌ对甲酚和１５０ｍＬ甲醇的混合物中,得到１８０ｇ２－溴对甲酚（Ⅰ）;（Ⅰ）与甲醇钠在１４５℃和１．０－１．２ＭＰａ条件下反应２．５ｈ生成１２４ｇ２－甲氧基甲酚（Ⅱ）;（Ⅱ）在乙酸钴存在下,用空气氧化得到４４ｇ香兰素,总收率为７０％。     

溴代反应中的选择性溴化剂

综述了四溴环酮，过溴型季铵盐等选择性溴化剂在溴代反应中的应用。     

盐酸美金刚胺的合成及表征

通过比较不同的反应路线，确定了以1，3-二甲基金刚烷为原料，经溴代、乙酰氨基化、水解反应最后经酸化得到盐酸美金刚胺。改进并优化了合成路线，溴代反应确定为在回流条件下反应12h，n（1，3-二甲基金刚烷）：n（溴素）=1：1．5；水解反应条件是以，7（乙二醇）：n（水）=10：1为溶剂，150℃下反应12h，n（1-乙酰氨基-3，5-二甲基金刚烷）：n（氢氧化钠）=1：5，反应总收率达81．5％。产品用IR、ESI、^1HNMR、^13CNMR确证了产品的结构。