共查询到19条相似文献,搜索用时 250 毫秒
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简要介绍了2-氯-5-氯甲基-1,3-噻唑作为化学原料的应用领域、市场前景、物化性状、其纯化方法。主要介绍了按不同起始原料的多种合成路线并分析其原料来源、合成质量、收率、成本。 相似文献
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以7-羟基香豆素和3-氯-3-甲基-1-丁炔为原料,分别采用不同的微波合成条件,经两步合成2,2-二甲基-1,5-二氧杂菲-6-酮。实验结果表明,与传统合成方法相比,微波合成不仅大大减少了反应的时间,还降低了原料的消耗,是合成Seselin的较优方法。 相似文献
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根据反应原料的不同,介绍了3,5-二甲基苯胺的六种主要合成方法,阐述了不同的合成方法得到的不同结果,比较了各种方法的可行性。其中3,5-二甲基苯酚法和2,4-二甲基苯酚法在工业生产中应用最广。前者因为原料价廉易得,且反应一步完成,副反应较少,最受研究者关注;后者芳伯胺法是最新研究的合成方法。 相似文献
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研究了以溴代异戊烯水解工艺和精馏分离工艺为基础来制备3-甲基-2-丁烯-1-醇的新工艺。通过优化溶剂种类得到当水解溶剂为偶极类溶剂乙腈时,得到产物的选择性最高。并通过进一步优化实验操作条件,得到当溶剂加入量为v(乙腈):v(溴代异戊烯)=1:1,水解温度为70℃,碱用量为n(NaOH):n(溴代异戊烯)=1.2:1和反应时间为25min时,水解部分3-甲基-2-丁烯-1-醇的转化率最高可达63.35%。水解后的料液通过间歇精馏得到纯的3-甲基-2-丁烯-1-醇,最终的3-甲基-2-丁烯-1-醇总收率达到57.4%。 相似文献
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Libor ervený Marcela Kuncov Barbora Vodov Vlastimil Rüi
ka 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1982,32(5):571-574
The effect of the amount of platinum and the type of the carrier on the selectivity for competitive hydrogenation of 2-methyl-3-butene-2-ol and hex-l-ene in methanol on platinum carrier catalysts has been studied. The effect of the type of the active component and carrier on the selectivity for competitive hydrogenation of 2-methyl-3-butene-2-ol and 2-phenylpropene in methanol and cyclohexane on various types of catalyst has also been investigated. Selectivity decreased with increasing amounts of platinum on the carrier and also with decreasing polarity of the carrier. The change in selectivity was greatest for a change in the active (metal) component of the catalysts; being in most cases several times higher in cyclohexane compared with methanol. 相似文献
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2-甲基-3-丁烯-2-醇合成3-甲基-2-丁烯-1-醇 总被引:1,自引:0,他引:1
[目的]2-甲基-3-丁烯-2-醇是异戊二烯间接皂化法生产3-甲基-2-丁烯-1-醇过程中产生的副产物,废物回收再利用是节能减排的有效措施.[方法]2-甲基-3-丁烯-2-醇经氯化、酯化和皂化得到3-甲基-2-丁烯-1-醇.[结果]结果表明:在优化条件下,氯化反应的产率可达87.25%,酯化和皂化反应的产率可达84.53%.[结论]该方法是2-甲基-3-丁烯-2-醇再利用的有效方法. 相似文献
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以2-氨基-4-氯吡啶为起始原料,经过缩合、取代、环合、乌尔曼反应和水合肼还原硝基5步反应得到中间体4-([1,2,4]三唑并[1,5-a]吡啶-7-氧基)-3-甲基苯胺,总收率28.8%。2-氨基-5-硝基苯腈先与N,N-二甲基甲酰胺二甲基缩醛(DMF-DMA)缩合,再与4-([1,2,4]三唑并[1,5-a]吡啶-7-氧基)-3-甲基苯胺环合得到N-[3-甲基-4-([1,2,4]三唑并[1,5-a]吡啶-7-氧基)苯基]-6-硝基-4-喹唑啉胺,再经硝基还原得到N4-[3-甲基-4-([1,2,4]三唑并[1,5-a]吡啶-7-氧基)苯基]-4,6-喹唑啉二胺,三步收率47.4%。同时,采用二硫化碳和2-氨基-2-甲基-1-丙醇为原料,经两步反应制备4,5-二氢-4,4-二甲基-2-(甲硫基)噁唑三氟甲磺酸盐,收率68.6%。最后,N4-[3-甲基-4-([1,2,4]三唑并[1,5-a]吡啶-7-氧基)苯基]-4,6-喹唑啉二胺和4,5-二氢-4,4-二甲基-2-(甲硫基)噁唑三氟甲磺酸盐以三乙胺为碱进行缩合反应得到妥卡替尼,收率62.8%,HPLC纯度99.08%。采用1HNMR、13CNMR和HRMS等对产物结构进行了表征。该合成路线原料廉价易得,为妥卡替尼的放大生产提供理论依据。 相似文献
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The effects that different headspace sampling methods have on the analysis of the ratios of compounds present in the headspace of a synthetic mixture and a biological sample were evaluated using the following methods: solid-phase microextraction (SPME), a syringe, and the porous polymers Porapak Q, Tenax TA, and Hayesep Q (thermal and solvent desorption). The performance of each method was only evaluated for a certain sampling period and under given experimental conditions. The test mixture comprised pentan-3-ol, 4-penten-1-ol, (E)-2-hexenal, hexan-1-ol, heptanal, (1S,5S)-(–)--pinene, 6-methyl-5-hepten-2-one, hexyl acetate, (R)-(+)-limonene, and undecane. SPME gave significantly different ratios of pentan-3-ol, 4-penten-l-ol, hexan-1-ol, heptanal, (1S,5S)-(–)--pinene, 6-methyl-5-hepten-2-one, hexyl acetate, limonene, and undecane compared with the other methods. No significant differences were observed between the syringe and the porous polymers or between the three different porous polymers used. The method of release of the trapped analytes from the polymers, thermal or solvent desorption, did not affect the ratios of compounds. The effects that different sampling methods have on the ratios of compounds present in the headspace of a biological sample, ripe banana, were evaluated. The headspace was sampled using SPME and the porous polymers Porapak Q and Tenax TA (thermal desorption). The following compounds were identified in the headspace of ripe bananas: 2-methylbutyl acetate, pentyl acetate, 2-methylbutyl propanoate, butyl butanoate, and pentyl butanoate. SPME gave significantly different ratios of 2-methylbutyl acetate, pentyl acetate, butyl butanoate, and pentyl butanoate when compared to Porapak Q and Tenax TA. No significant differences on the ratios of compounds present in the headspace of ripe banana were observed when the two polymers were compared. The use of different sampling methods in headspace analysis of biological samples is dicussed. 相似文献