共查询到19条相似文献,搜索用时 98 毫秒
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3,4-二氢嘧啶酮衍生物具有重要生理活性,因此该类化合物的合成受到广泛关注。以廉价的三聚氯氰催化芳醛、尿素和乙酰乙酸乙酯或环戊酮的“一锅法”Biginelli反应,在无溶剂和无保护的条件下合成了一系列芳亚甲基稠环嘧啶酮化合物,其中代表性化合物结构经NMR、IR和熔点等表征手段确定。该方法所用催化剂经济易得,且催化剂用量较少,反应条件温和,产率较高,为3,4-二氢嘧啶-2(1H)-酮衍生物的合成提供了新的方法。 相似文献
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研究了在碘催化下亚胺与烯醇醚的反应,以较高的产率获得了预期的四氢喹啉产物。详细考察了催化剂的用量、亚胺的结构以及烯醇醚的结构对这一反应的影响。所得化合物经1 H NMR、13C NMR测试技术进行表征。 相似文献
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采用浸渍法以金属有机骨架Cu_3(BTC)_2负载锗钨酸(H_4GeW_(12)O_(40))制备H4Ge W_(12)O_(40)/Cu_3(BTC)_2催化剂,并用该催化剂催化芳醛、尿素和乙酰乙酸乙酯通过"一锅法"Biginelli缩合反应,以无水乙醇为溶剂,合成6种3,4-二氢嘧啶-2(1H)-酮衍生物;通过熔点的测定,IR,1H NMR和MS等对产物3,4-二氢嘧啶-2(1H)-酮衍生物进行表征。结果表明:在芳醛用量为0.04 mol,n(芳醛)∶n(乙酰乙酸乙酯)∶n(尿素)=1∶1.5∶1.5,催化剂的用量占反应物料总质量的4.0%,反应温度为90℃,反应时间为90 min的条件下,目标产物收率可达63.0%~76.3%。 相似文献
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以二氢高红霉素(去甲基阿奇霉素)为原料,经CbzCl保护、Swern氧化、环氧化、烯丙基胺开环氧和钯碳催化加氢五步反应以46%的总收率合成了泰拉霉素(纯度97%),其结构经液相色谱与标准品对比确认。烯丙基胺乙醇溶液开环氧与催化加氢两步反应实现一锅法,简化了工艺操作,降低了分离难度,加之采用钠氢作无机碱和TFA成盐条件,减少了副反应的发生,提高了收率和产品纯度。 相似文献
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以色酮类化合物和1,3一二取代5-氨基吡唑化合物为原料,在分子碘催化下制备一系列新颖的多取代吡唑【3,4-b】吡啶衍生物(3a-3j),收率高达85%-92%,所有化合物的结构经^1HNMR和MS等表征。 相似文献
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通过设计正交试验,以1,4-二乙氧基苯为原材料,碘为催化剂,二氯甲烷、冰醋酸为溶剂,制备得到1,4-二溴-2,5-二乙氧基苯并优化试验条件。以1,4-二乙氧基苯1.66 g(0.01 mol),二氯甲烷15 m L为不变量,得到最佳试验条件:反应时间10 h,V(CH3COOH)∶V(CH2Cl2)=1∶3,0.7 m L溴,0.03 g碘。并通过红外、核磁共振氢谱和碳谱进行表征。 相似文献
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Intramolecular cyclic etherification of 1,3-diols was investigated using iodine as a catalyst under solution reaction conditions. Compounds containing five-membered ether rings were obtained. Propella ether (11-oxatricyclo[4.4.3.0(1,6)]tridecane) was conveniently synthesized from 1,3-diol (6-(2-hydroxyethyl)spiro[4.5]decan-6-ol) in 97% yield via carbon skeleton rearrangement. Spiroethers and bicyclic ethers were also obtained from the corresponding 1,3-diols in yields of over 77%. The most suitable reaction conditions were a temperature of 80 degrees C, a 1:0.2 molar ratio of 1,3-diol:iodine, and a time period of 8 h. In addition, terpenoic ethers were efficiently synthesized from the corresponding 1,3-diols, derived from (+)-camphor and (-)-fenchone, via skeleton rearrangement. In particular, the reaction of the 1,3-diol derived from (+)-camphor proceeded smoothly at room temperature with a yield of 91%. The yield of the cyclic ether using iodine as a catalyst was comparable to the method using sulfuric acid. 相似文献
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以碘作为环己醇的脱水剂成功地制备了环己烯,探讨了催化剂用量、反应温度、反应时间对脱水反应的影响。不同催化剂活性比较等问题。结果表明,碘是环己醇脱水制备环己烯的良好催化剂。最佳工艺条件为:催化剂用量为环己醇质量的6.2%,反应温度80~90℃,反应时间4 h,收率68.39%。 相似文献
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以正丁胺为原料,与光气合成正丁基异氰酸酯,再与2-丙炔-1-醇反应得2-丙炔基正丁氨基甲酸酯,最后与一氯化碘反应得碘代丙炔基正丁氨基甲酸酯。研究了物料配比、反应温度及催化剂选择对反应结果的影响,产品含量达99%以上,产品总收率达93%(以2-丙炔-1-醇计,n/n),此工艺适宜于工业化。 相似文献
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A highly rapid process is described for the preparation of cellulose triacetate and its effect on particle size and surface area of the product. The process involves microwave-assisted rapid synthesis of cellulose triacetate with very low amount of acetic anhydride (10–15% of acetic anhydride is used in conventional methods) in the presence of iodine as a catalyst using a designed reaction vessel. The technique used is simple and rapid; it is also characterized by a high conversion ratio (yield 100%). A small amount of iodine (115 and 230 mg, 1.15 and 2.3% of cellulose weight) was found to be effective in the production of cellulose triacetate using 25, 30 to 40 mL acetic anhydride for 10 g cellulose under microwave irradiation for 2–4 min. The production of cellulose triacetate and the degree of substitution were confirmed by FTIR, Raman, 1H NMR, and thermogravimetric analysis. The optimal reaction condition was discovered to be 3 min microwave radiation and 30 mL acetic anhydride in the presence of 230 mg iodine for 10 g cellulose. The effects of the amount of acetic anhydride, and amount of catalyst and reaction time on the specific surface area, pore volume, mean pore diameter, and particle size distribution were investigated. The highest surface area obtained was 39.63 m2/g. The specific surface area and particle size distribution are highly dependent on the amount of acetic anhydride and I2 catalyst. About 10% of the synthesized cellulose acetate showed particle size less than 200 nm. 相似文献