共查询到20条相似文献,搜索用时 62 毫秒
1.
以2,3-二甲基吡啶为原料,经过氧化、硝化、取代、酰化以及氯化反应,合成目标产物2-氯甲基-3-甲基-4-(2,2,2-三氟乙氧基)-吡啶,5步总收率为35.6%。对中间体2,3-二甲基-4-(2,2,2-三氟乙氧基)-吡啶-N-氧化物的合成条件进行了优化选择,其较佳的合成条件:甲基异丁基甲酮作为溶剂,四丁基溴化铵为相转移催化剂,n(三氟乙醇)∶n(K2CO3)∶n(2,3-二甲基-4-硝基吡啶-N-氧化物)=4.5∶1.2∶1,反应时间12 h,反应温度95℃,所得中间体收率91.9%,所得中间体结构经1HNMR表征,确定为2,3-二甲基-4-(2,2,2-三氟乙氧基)-吡啶-N-氧化物。 相似文献
2.
提供了一种用三氟乙氧基化反应和加氢还原制备三氟乙氧基苯胺的方法。以邻氯硝基苯和对氯硝基苯为原料,与三氟乙醇钠在120℃反应5h,制得邻位和对位两种三氟乙氧基硝基苯,收率分别为87.1%和95.8%;两种三氟乙氧基硝基苯经钯炭催化剂催化加氢还原,75℃反应1h,得目标化合物2-(2,2,2-三氟乙氧基)苯胺和4-(2,2,2-三氟乙氧基)苯胺,收率分别为94.5%和95.2%。产物结构经1HNMR和IR确证。 相似文献
3.
以商品化2,5-二(2,2,2-三氟乙氧基)苯甲酸为原料,二氯亚砜为酰氯化试剂,得到2,5-二(2,2,2-三氟乙氧基)苯甲酰氯,再与2-氨甲基哌啶反应得到盐酸氟卡尼,选用不同醇溶剂通过碱中和再与醋酸络合成盐,得到目标产物醋酸氟卡尼。考察了原料配比、反应时间以及溶剂对收率的影响,优选的反应条件为:n〔2,5-二(2,2,2-三氟乙氧基)苯甲酸〕∶n(2-氨甲基哌啶)= 1∶1.8,其中原料酸先活化成酰氯,再与2-氨甲基哌啶在THF为溶剂,冰浴搅拌2h,得到盐酸氟卡尼;再以乙醇为溶剂,氢氧化钠为碱,回流中和0.5 h,近似定量得到氟卡尼;最后选用异丙醇为溶剂,与醋酸回流0.5 h,冷却析出得到目标产物。四步反应总收率为39.2%,经过路线中两次固体结晶,最终产物醋酸氟卡尼液相色谱纯度高于99.7%。 相似文献
4.
以商品化2,5-二(2,2,2-三氟乙氧基)苯甲酸(Ⅰ)为原料,二氯亚砜为酰氯化试剂,得到2,5-二(2,2,2-三氟乙氧基)苯甲酰氯(Ⅱ),中间体Ⅱ再与2-氨甲基哌啶反应得到盐酸氟卡尼(Ⅲ),化合物Ⅲ通过碱中和再与醋酸络合成盐得到目标产物醋酸氟卡尼.考察了投料比、反应时间以及溶剂对化合物Ⅲ收率的影响,优选的反应条件为:n(Ⅰ):n(2-氨甲基哌啶)=1:1.8(其中,化合物Ⅰ先活化成酰氯),以四氢呋喃为溶剂,冰浴搅拌2.0 h,得到盐酸氟卡尼.再以乙醇为溶剂,NaOH为碱,回流中和0.5 h,得到氟卡尼(Ⅳ);最后,选用异丙醇为溶剂,中间体Ⅳ与醋酸回流0.5 h,冷却析出得到目标产物.4步反应总收率为39.2%,经过两次结晶,最终产物醋酸氟卡尼HPLC纯度高于99.7%. 相似文献
5.
以商品化2,5-二(2,2,2-三氟乙氧基)苯甲酸(Ⅰ)为原料,二氯亚砜为酰氯化试剂,得到2,5-二(2,2,2-三氟乙氧基)苯甲酰氯(Ⅱ),中间体Ⅱ再与2-氨甲基哌啶反应得到盐酸氟卡尼(Ⅲ),化合物Ⅲ通过碱中和再与醋酸络合成盐得到目标产物醋酸氟卡尼.考察了投料比、反应时间以及溶剂对化合物Ⅲ收率的影响,优选的反应条件为:n(Ⅰ):n(2-氨甲基哌啶)=1:1.8(其中,化合物Ⅰ先活化成酰氯),以四氢呋喃为溶剂,冰浴搅拌2.0 h,得到盐酸氟卡尼.再以乙醇为溶剂,NaOH为碱,回流中和0.5 h,得到氟卡尼(Ⅳ);最后,选用异丙醇为溶剂,中间体Ⅳ与醋酸回流0.5 h,冷却析出得到目标产物.4步反应总收率为39.2%,经过两次结晶,最终产物醋酸氟卡尼HPLC纯度高于99.7%. 相似文献
6.
7.
8.
对以五氯吡啶为起始原料合成4-氨基-3,5-二氯-2,6-二氟吡啶的工艺进行了改进,研究了相关因素对4-氨基-3,5-二氯-2,6-二氟吡啶收率的影响。结果表明,反应中水分对氟交换反应影响很大,无水条件下氟交换反应温度为100~158℃时中间体3,5-二氯-2,4,6-三氟吡啶收率超过80%;无水KF无需预先用烘箱干燥,氟化产物无需用精馏塔分离,且氨化反应无需耐高温高压设备(室温即可反应),产物总收率为70.4%。此方法操作简单、反应条件温和、设备投资少、生产成本低,具有较高的实用价值。 相似文献
9.
研究了氟草烟的重要中间体4-氨基-3,5-二氯-2,6-二氟吡啶的合成新方法。以五氯吡啶为原料,采用分子筛控制水分,经氟化、氨基化一锅法合成4-氨基-3,5-二氯-2,6-二氟吡啶。最佳反应条件为:氟化反应水分含量0%~0.001%,氟化反应温度110~120℃,氨化反应温度为0~5℃,氨水浓度为20%~22%。最终4-氨基-3,5-二氯-2,6-二氟吡啶的合成收率达到83%以上,含量达到85.0%。 相似文献
10.
11.
12.
3,5-二氯-1-甲基-4-吡唑羧酸酯作为起始原料,用一步法制备了3,5-二氯-1-甲基-4-吡唑羧酸。 相似文献
13.
14.
Studies on Ring Cleavage of Some 4-(4-Nitrophenylazo)-substituted Pyrazolidine-3,5-dione-Derivatives Continuing to previous investigations the ring cleavage of the pyrazolidine compounds 3 and 7 is studied under the influence of KOH and CH3ONa. Due to the different substitution of atoms of the heterocyclus this reaction was expected to result in at least two isomeric compounds. Actually this assumption was only confirmed for 3 . So the reaction of 3 with CH3ONa yields a mixture of four isomers ( 4a - 4d ) with 4a as main product. On the other hand, when 7 is treated with CH3ONa or KOH only one product is formed. With regard to the great structural similarity of the possible isomers, mass spectroscopy proved to be the best test of whether the ring cleavage occurs between C-3 and C-4 or C-4 and C-5 of the heterocyclus. 相似文献
15.
以羟基乙酸,一水合肼为原料,在微波辐射下合成了多齿配体4-氨基-3,5-二羟甲基-1,2,4-三唑。讨论了微波反应时间、微波功率、原料配比对4-氨基-3,5-二羟甲基-1,2,4-三唑收率的影响,得到最优条件;微波反应时间90 min,微波功率480 W,一水合肼/羟基乙酸=1.5/1。新的合成方法使反应时间由文献报道的24 h缩至90 min,缩合反应的收率由文献报道的58%提高到78%。 相似文献
16.
G. Zvilichovsky 《Israel journal of chemistry》1971,9(6):659-666
3,5-Dihydroxy-4-phenylisoxazole, which is described here, is the first known 3,5-dihydroxy derivative of isoxazole. Its unusual physical and chemical properties were studied. The tautomeric structures and the methylation products are elucidated. 相似文献
17.
Summary 4-(4-Dimethylaminophenyl)-1,2,4-triazolidine-3,5-dione (DAPTD) was prepared from 4-dimethylaminobenzoic acid in five steps. The reaction of monomer DAPTD with n-isopropylisocyanate was performed at room temperature in N,N-dimethylacetamide (DMAc) solution and the resulting bis-urea derivative was obtained in high yield and was finally used as
a model compound for polymerization reaction. The step-growth polymerization reactions of monomer with hexamethylene diisocyanate
(HMDI), isophorone diisocyanate (IPDI) and toluene-2,4-diisocyanate (TDI) were performed in DMAc solution in the presence of pyridine, triethylamine or dibutyltin dilurate as catalysts. Some physical
properties and structural characterization of these novel polyureas are reported. Fluorimetric studies of the model compound
as well as polymers were performed. 相似文献
18.
19.
Summary We have synthesized 4-(1-naphthyl)-1,2,4-triazolidine-3,5-dione (4-NTD) in high yield and purity from 1-naphthyl isocyanate and used it as a new monomer for polymer synthesis. A series of novel
naphthalene-containing polyureas have been successfully prepared from 4-NTD with hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI) and toluene-2,4-diisocyanate (TDI) in N,N-dimethylacetamide (DMAc) or N-methylpyrrolidone (NMP) solution in the presence of pyridine, triethylamine or dibutyltin dilurate as catalysts. Some physical
properties and structural characterization of these novel polyureas are reported. Fluorimetric studies of the new monomer,
model compound as well as polymers were also investigated. 相似文献
20.
4-氨基-3,5-二(4-吡啶)-1,2,4-三氮唑的合成方法已有报道,但合成条件严格,要求纯氮气保护.本文的合成方法简单易行,无须氮气保护,只需反应物直接混合加热就可得到产物. 相似文献