首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 187 毫秒
1.
宋尚海  秦凤菊 《杭州化工》2005,35(2):21-22,29
2-氯-5-甲基吡啶是生产农药吡虫清、吡虫啉的重要中间体,它能降低农药吡虫啉等的原料成本。讨论了以2-氨基-5-甲基吡啶氯化法,经重氮化上氯而得的合成路线,实验讨论了反应温度、反应时间、反应物摩尔比对产品收率的影响。  相似文献   

2.
王红明  李健  葛九敢  齐武  周建华  薛谊 《世界农药》2012,34(6):26-27,32
以3-甲基吡啶为原料,CuCl/HC1为氯化剂,合成得到2-氯-5-甲基吡啶.考察了氯化剂中CuCl和HCl的不同用量对2-氯-5-甲基吡啶产率的影响.结果表明,反应温度110℃,反应时间9h,3-甲基吡啶氧化物、CuCl及HC1三者摩尔比4.5∶3∶9为最佳试验条件,2-氯-5-甲基吡啶收率达到最大值75%.  相似文献   

3.
以对苯二酚与2,3-二氯-5-三氟甲基吡啶单醚化合成精吡氟氯禾灵的重要中间体2-(4’-羟基苯氧基)-3-氯-5-三氟甲基吡啶。探讨并得到了反应的最佳工艺条件:K2CO3为缚酸剂,二甲基亚砜和甲苯为溶剂,n(2,3-二氯-5-三氟甲基吡啶):n(对苯二酚):n(K2CO3)=1:2:1.08,不需要脱水。在回流条件下加入2,3-二氯-5-三氟甲基吡啶并反应5h。在此条件下,2,3-二氯-5-三氟甲基吡啶的转化率100%,产品的选择性大于98%。  相似文献   

4.
采用一锅法,以2-氰基甲基-3-氯-5-三氟甲基吡啶为原料,在甲醇中与氢氧化钠70℃得到中间产物2-(3-氯-5-三氟甲基-2-吡啶)乙酰胺,之后再与氢氧化钠和次氯酸钠溶液在10℃反应制得2-氨甲基-3-氯-5-三氟甲基吡啶盐酸盐,收率98.57%。该方法避免高压反应,原材料易得,收率较高。  相似文献   

5.
3-甲基吡啶法生产2-氯-5-三氟甲基吡啶   总被引:5,自引:0,他引:5  
叙述了2 -氯 -5 -三氟甲基吡啶的四种合成方法 ,着重介绍了3 -甲基吡啶法生产2 -氯 -5-三氟甲基吡啶的生产工艺及其特点。  相似文献   

6.
以2-氨基-5-甲基吡啶为原料,经重氮化、氯代热解反应制得了2-氯-5-甲基吡啶,研究了浓盐酸用量、亚硝酸钠用量、氯代温度、氯代时间、不同氯代剂对2-氯-5-甲基吡啶收率的影响。优化工艺条件为:氯化亚铜为催化剂,n(2-氨基-5-甲基吡啶)∶n(盐酸)=1∶3、n(2-氨基-5-甲基吡啶)∶n(亚硝酸钠)=1∶1.1、重氮化温度为0~5℃,氯代温度45℃、氯代时间8 h、稀盐酸为氯代剂,优化条件下产品的收率为74.76%。  相似文献   

7.
本发明以2-氰基-3-氯-5-三氟甲基吡啶为原料,在溶剂醋酸中经过低压加氢还原一步得到2-氨基甲基-3-氯-5-三氟甲基吡啶的盐酸盐。本发明方法优点在于设备要求低、收率高、易工业化生产等优点。  相似文献   

8.
2-(4′-羟基苯氧基)-3-氯-5-三氟甲基吡啶的合成   总被引:2,自引:0,他引:2  
以对苯二酚与2,3-二氯-5-三氟甲基吡啶单醚化合成精吡氟氯禾灵的重要中间体2-(4′-羟基苯氧基)-3-氯-5-三氟甲基吡啶。探讨并得到了反应的最佳工艺条件:K2CO3为缚酸剂,二甲基亚砜和甲苯为溶剂,n(2,3-二氯-5-三氟甲基吡啶)∶n(对苯二酚)∶n(K2CO3)=1∶2∶1.08,不需要脱水。在回流条件下加入2,3-二氯-5-三氟甲基吡啶并反应5 h。在此条件下,2,3-二氯-5-三氟甲基吡啶的转化率100%,产品的选择性大于98%。  相似文献   

9.
2-氟-3-氯-5-三氟甲基吡啶是一种重要的含氟吡啶类中间体,在农药、医药合成中有广泛的应用。综述了2-氟-3-氯-5-三氟甲基吡啶的常用合成路线,并对各条合成路线作了比较和评价。  相似文献   

10.
略述了吡啶及其衍生物的某些研究动态,主要概述2-氯-5-甲基吡啶的合成以及在合成农药特别在作为除草剂原料或中间体中的应用,它们包括:2-氯-5-甲基吡啶-N-氧化物,2-氯-5-三氟甲基吡啶,2-氯-5-氯甲基吡啶、2-氯-3-甲基吡啶等,展望了吡啶及其衍生物的发展前景。  相似文献   

11.
Synthesis and Application of Immobilized Catalysts for the Heterogeneously Catalyzed Cleavage of the Si Si Bond of Chloromethyldisilanes Lewis bases like bis(dimethylamide)phosphoryl compounds (2, 5–7) , N-heterocycles ( 8 and 9 ) and N,N-dialkylamino-3-propylsilanes bearing alkoxy groups are grafted via siloxane bonds onto silica carriers. The preparation and characterisation of 5–9 are reported. The grafted bis(dimethylamide)phosphoryl compounds (2, 5–7) and N-heterocycles (8, 9) are efficient catalysts for the disproportionation of chloromethyldisilanes into chloromethyloligosilanes and chloromethylsilanes. Grafted N,N-dialkylamino-3-propylsilyl compounds heterogeneously catalyze the Si Si bond cleavage of the disilanes with hydrogen chloride at 170 °C in excellent yields. A mixture of chloromethylmonosilanes is obtained. This reaction is also performed under pressure.  相似文献   

12.
2-戊基蒽醌的合成研究   总被引:2,自引:0,他引:2  
首次以苯和叔戊醇为基础原料经烷基化、酰基化和关环3 步反应合成了2 戊基蒽醌。改进和优化了各步合成工艺条件:在三氯化铝- 硫酸双酸催化下,当n(AlCl3)∶n(H2SO4)= 1∶1-25,n(C6H6)∶n(t C5H11OH) =9∶1,温度6 ℃,反应4 h 时,戊苯收率为79-3% ;在2 甲基吡啶存在下,中间体2 (4′ 戊基苯甲酰) 苯甲酸收率为80-2 % ;关环反应采用氯仿为溶剂,利用类似分水器的装置,有效控制反应温度使炭化减少,2 戊基蒽醌收率为81-4 % 。  相似文献   

13.
Photocatalytic oxidation of methylpyridine isomers (2-methylpyridine, 3-methylpyridine, and 4-methylpyridine) was investigated in a mixed solution of acetonitrile and water or acetonitrile using various kinds of TiO2 powders as photocatalysts. The main products from methylpyridine isomers were pyridinecarboxaldehyde isomers (2-pyridinecarboxaldehyde, 3-pyridinecarboxaldehyde, and 4-pyridinecarboxaldehyde). Rutile large TiO2 particles showed the highest level of activity for oxidation of 2-methylpyridine probably because band bending was necessary for the oxidation of 2-methylpyridine. On the other hand, a fine particle having an anatase or rutile phase showed a higher level of activity than large TiO2 particles for oxidation of 3-methylpyridine. A rutile fine particle showed the highest level of activity for the reaction. It was found that pure rutile or pure anatase particles were inactive for oxidation of 4-mathylpyridine. If the particles are not extremely small, pure rutile and pure anatase powders show fairly high levels of activity, and those containing both anatase and rutile phases show the highest level of activity. The activity of pure rutile particles was also enhanced by physically mixing them with a small amount of small anatase particles, which were inactive for this reaction. These results can be explained by the synergism between rutile and anatase particles. All of these reactions effectively proceeded even under anaerobic conditions. Photocatalytic reduction of methylpyridine isomers concomitantly proceeded on TiO2 particles under the conditions used. These results suggest that the activities of TiO2 photocatalysts for oxidation of methylpyridine isomers are dominated by the oxidation potential of alkylpiridine and band bending of TiO2 particles.  相似文献   

14.
Cellulose flame retarded with an ammonia‐cured, polycondensed tetrakis(hydroxymethyl)phosphonium–urea derivative (as Proban CC®, Rhodia) phosphorylated by cyclic 1,3‐propanediol phosphoryl chloride and cyclic 2,2‐diethyl‐1,3‐propanediol phosphoryl chloride can give phosphorus levels up to 6.9% (w/w). Such high levels suggest up to 35.5% yields of reaction if the free secondary amine groups present in the crosslinked flame retardant and the C(6) primary hydroxyl groups are the assumed phosphorylation sites. The presence of substituted propanediol phosphonate moieties in the fibers significantly increases char formation above 400©C and scanning electron microscopy indicates that the char has an intumescent structure. The influence of the chemical structure of the propanyl moeity to the reaction extent of the possible phosphorylation sites and the char formation mechanism during thermal pyrolysis of the modified samples are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3165–3172, 2003  相似文献   

15.
研究了合成二-(2-乙基己基)磷酸的工艺优化条件,通过加入无水AlCl3,严格控制反应温度,控制三氯氧磷加入量过量3%等措施,合成的二-(2-乙基己基)磷酸萃取稀土元素性能优于标准萃取剂。  相似文献   

16.
乙酰苯胺合成新方法   总被引:1,自引:0,他引:1  
报道了以N,N-二甲基乙酰胺(DMAc)为乙酰化试剂,苯胺在氯化铵的作用下合成乙酰苯胺的新方法.研究了反应温度和原料配比等因素对乙酰苯胺产率的影响,确定最佳反应条件为:N,N-二甲基乙酰胺为乙酰化试剂和溶剂,n(氯化铵):n(苯胺)=2:1、反应温度166℃、回流反应时间3h,此条件下乙酰苯胺产率达到98.0%.与常规...  相似文献   

17.
Pentaerythritol bonded to cross‐linked poly(vinylbenzyl chloride) beads (PE) provides a scaffold onto which ligands can be attached by reaction with reactive compounds such as phosphoryl halides. To broaden the applicability of PE for the preparation of ion‐selective polymers, conditions are reported for the conversion of the hydroxyl group to the bromide, which acts as a better leaving group. The ? CH2Br moiety thus provides a handle on which an array of ligands can be bound through nucleophilic substitution. In this first in a series of reports, immobilization of diethylamine onto the PE and the ion‐binding affinities of the resulting polymer are described. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

18.
棉织物阻燃剂PN的合成工艺改进   总被引:3,自引:0,他引:3  
房晓敏  王彦林  刘治国  徐元清  丁涛 《精细化工》2001,18(6):337-338,347
棉织物阻燃剂PN(N 羟甲基 3 二甲氧磷酰基丙酰胺 )合成工艺的改进如下 :(1)Michael加成反应中 ,采用无溶剂法合成 3 二甲氧磷酰基丙酰胺中间体 ,加入防自聚剂DMP ,避免了丙烯酰胺的聚合 ,增加了反应的定向性 ,产率可达 98.5 % ;(2 )羟甲基化反应中 ,用弱碱多次调pH值 ,使产品的羟甲基值达 13.0 % ,游离甲醛的质量分数小于 1.2 % ,并且探讨了减压蒸馏温度、压力、时间等条件对产品羟甲基值、游离甲醛含量的影响  相似文献   

19.
采用三氯氧磷法合成了一种新型五取代有机胍 N,N,N′,N′-四甲基-N″-苯基胍(PhTMG),利用IR、1H NMR、ESI-MS等方法对其结构进行了表征。考察了PhTMG对以二甘醇(DEG)、氯丙烯(ACH)和CO2为原料合成二甘醇双烯丙基碳酸酯(ADC)反应的催化性能,ADC的最高收率为95.3%。采用GC-MS、XRD、IR等分析手段结合实验验证对ADC合成反应机理进行了研究,推测出该反应分4步进行:第1步,CO2、DEG和Na2CO3反应生成二甘醇单碳酸钠盐;第2步,二甘醇单碳酸钠盐和ACH反应生成二甘醇单烯丙基碳酸酯(DGAC);第3步,DGAC、CO2和Na2CO3反应生成二甘醇单烯丙基碳酸酯单碳酸钠盐;第4步,二甘醇单烯丙基碳酸酯单碳酸钠盐与ACH反应生成目的产物ADC。并推测了反应体系中的主要副反应。  相似文献   

20.
二乙醇胺和对甲苯磺酰氯在三乙胺存在下,反应生成N,0,O′-三(对甲苯磺酰基)双(2-羟乙基)胺,产率93%。从反应混合物中分离得副产物N,O-二(对甲苯磺酰基)双(2-羟乙基)胺。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号