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二甲基对溴碘代苯是带有两种不同卤素基团的芳香族有机合成中间体。2,6-二甲基苯胺在过碳酸钠作用下,于45~50℃与碘反应1 h,得到2,6-二甲基-4-碘苯胺,收率42.5%。2,6-二甲基-4-碘苯胺在-5~0℃下进行重氮化,进一步与溴化亚铜发生Sandm eyer反应,得到3,5-二甲基-4-溴碘苯,收率31.5%。2,6-二甲基苯胺室温下与六亚甲基四胺溴络合物反应30 m in,得到2,6-二甲基-4-溴苯胺,收率62.0%。2,6-二甲基-4-溴苯胺在-5~0℃进行重氮化,与K I反应,得到2,6-二甲基-4-溴碘苯,收率33.1%。通过熔点、红外光谱和核磁共振氢谱对中间体2,6-二甲基-4-碘苯胺、2,6-二甲基-4-溴苯胺以及最终产物3,5-二甲基-4-溴碘苯和2,6-二甲基-4-溴碘苯进行了表征。 相似文献
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为了制备2,6-二甲基-4-苯基-3,5-吡啶二甲酸,首先采取Hantzsch合成法,以0.10 mol苯甲醛、0.125 mol碳酸氢铵和0.25 mol乙酰乙酸乙酯为原料,在40 mL甲醇溶剂中回流0.5 h,合成了1,4-二氢-2,6-二甲基-4-苯基-3,5-吡啶二甲酸二乙酯,产率为45.9%;取0.01 mol 1,4-二氢-2,6-二甲基-4-苯基-3,5-吡啶二甲酸二乙酯在0.02mmol六水三氯化铁的醋酸水溶液中回流反应1 h进行芳构化合成了2,6-二甲基-4-苯基-3,5-吡啶二甲酸二乙酯,产率为50.2%;最后,2,6-二甲基-4-苯基-3,5-吡啶二甲酸二乙酯进行水解合成目标产物,产率为62.7%。 相似文献
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研究了2,6-二甲基苯酚在玻碳电极上的电化学行为。通过线性扫描伏安法研究了支持电解质、溶液pH和扫描速度对2,6-二甲基苯酚测定的影响。并采用示差脉冲伏安法研究了氧化峰电流与2,6-二甲基苯酚浓度之间的关系,结果显示峰电流与2,6-二甲基苯酚的浓度在7.0×10^-5~2.0×10^-2 mol/L之间有良好的线性关系。同时玻碳电极对2,6-二甲基苯酚的测定具有较好的重现性和稳定性。 相似文献
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文章综述了2,4-和2,6-二甲基硝基苯制备工艺的三种硝化方法,对于混酸用量、反应时间以及反应温度对硝化反应的影响进行了探讨。(1)分段硝化法,通过用混酸硝化间二甲苯,一段硝化,在温度为15℃反应1 h,二段硝化,在温度为25℃反应1 h,制得的产品中2,6-二甲基硝基苯产率可达25%。(2)以1,2-二氯乙烷为溶剂,间二甲苯为原料在30℃经混酸硝化制得2,4-和2,6-二甲基硝基苯,收率达96%。(3)用硫酸汞做催化剂,催化硝化间二甲苯,采用98%的浓硫酸在汞盐催化下直接双磺化,克服了采用发烟硫酸操作上的不便,降低了成本,有易于工业化生产。 相似文献
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以 β 环糊精为原料 ,经烷基化分两步取代羟基 ,合成了 2 ,6 二甲基 3 乙基 β环糊精 ,并用IR与H1 NMR将两步合成产物作了定性描述 ,验证了本文选择的合成路线 相似文献
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Several narrowly disperse polystyrenes (PS) were mixed with three series of random copolymers of 2,6-dimethyl phenylene oxide (also known as xylenyl ether (XE)) and 3-bromo-2,6-dimethyl phenylene oxide (BrXE), each series having a fixed chain length. The critical BrXE comonomer concentration necessary to induce phase separation, xc′ was characterized for each blend series by a number of techniques. xc was extrapolated to a value of about 0.5 at infinite chain lengths of each polymer of the blend. This finding supports the negative heat of mixing of PS with PXE reported by other workers. Small-angle neutron scattering studies were carried out using small amounts of perdeuteropolystyrene in several matrices for which single phase behaviour had been shown to exist. The radius of gyration R2 and the second virial coefficient A2 were greatest in the pure PXE matrix reflecting the goodness of this material as a ‘solvent’ for PS. In matrices containing copolymer, A2 extrapolated to zero at xc ≥ 1 which was consistent with the phase behaviour of this series of blends. 相似文献
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The intrinsic birefringence of atactic polystyrene and poly(2,6-dimethyl 1,4-phenylene oxide) in their compatible blends are obtained from coupled birefringence and infra-red dichroism measurements. The experimental value obtained for poly(2-6-dimethyl 1,4-phenylene oxide) is in reasonable agreement with the value calculated from bond polarizabilities. These results allow evaluation of the angle between the normal to the benzene ring of polystyrene and the chain axis. This angle appears to be constant as a function of draw ratio and poly(2,6-dimethyl 1,4-phenylene oxide) percentage in the 0–35% studied range. 相似文献
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Rare upper critical solution temperature (UCST) behavior was found and experimentally demonstrated in the blend comprising poly(2,6-dimethyl p-phenylene oxide) with poly(4-methyl styrene) (PPO/P4MS). Complexity of phase behavior in the PPO/P4MS system has caused puzzling analyses in the past years. This study re-investigated and clarified past mis-interpretations related to this interesting blend system. This study concluded that the PPO/P4MS blend is an immiscible system at ambient, which, however, turns into a miscible phase with UCST behavior at higher temperatures. With the finding of UCST in the PPO/P4MS blend, a critical contribution of this work was to resolve the conflicting arguments that have gone on for a long time in determination and interpretation of the thermodynamic phase behavior of PPO/P4MS. Phase behavior with UCST in the PPO/P4MS blend system and its interpretation were supported with clear experimental evidence. 相似文献
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分别以邻二甲苯和对硝基甲苯为起始原料,通过两种不同方法制备标题化合物。邻二甲苯经酰化、成肟、贝克曼重排、水解得到目标产物,纯度达98%,总收率53%。以对硝基甲苯为原料,经N-(2-甲基-5-硝基苄基)乙酰胺中间体合成标题化合物,纯度达99%,总收率50%。产物均经红外、核磁、质谱确认结构。 相似文献
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2,6-萘二甲酸(2,6-NDCA)及其衍生物是制备各种聚酯和聚氨酯材料的重要单体,在钛材间歇式搅拌釜中,以2,6-二甲基萘为原料,醋酸钴、醋酸锰、醋酸钾和溴化物等为催化剂,研究了2,6-二甲基萘空气液相氧化制备2,6-萘二甲酸的过程。确定n(Co+Mn)/n(HAc),n(Co)/n(Co+Mn),n(Br)/n(Co+Mn),n(Co+Mn)/n(2,6-DMN),n(K+)/n(Co+Mn)和助催化剂对收率和纯度的影响,从而得到比较适宜的催化条件。在此催化条件下,还考察了引发温度、反应压力、反应温度、溶剂比以及醋酸的浓度对收率和纯度的影响,确定了最佳合成2,6-萘二甲酸反应条件。 相似文献