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1.
3-氨基-2-羟基-4-苯基丁酸的合成;乌苯美司;氨基羟基苯基丁酸;合成  相似文献   

2.
丁酸戊酯在用H2SO4改性的H-β沸石上的催化合成   总被引:11,自引:0,他引:11  
赵振华 《合成化学》2002,10(6):539-541
以H2SO4改性的H-β沸石作催化剂合成了丁酸戊酯,考察了合成条件对正丁酸与正戊醇酯化反应的影响。适宜的反应条件为:催化剂用量8.8g/mol正丁酸,mol正戊酸:mol正戊醇=1:1.2,带水剂环己烷用量18mL/mol正丁酸,反应温度157℃~165℃,反应时间3h。在此反应条件下正丁酸的转化率在83%以上。该催化剂能够重复使用,所得正丁酸的转化率与新鲜催化剂的几乎相同。  相似文献   

3.
十二水合硫酸铁铵催化合成丁酸异戊酯   总被引:9,自引:0,他引:9  
刘华亭  林进 《合成化学》2000,8(6):550-552
以十二水合硫酸铁铵为催化剂,由丁酸和异戊酸合成了丁酸异戊醋,优化了酯化条件。实验结果表明,催化剂的催化活性高,反应条件温和,易于操作,方法简便,酯化率可达96.5%。  相似文献   

4.
用β沸石分子筛作催化剂液-固相合成丁酸戊酯的研究   总被引:7,自引:0,他引:7  
赵瑞兰  赵振华  李龙 《合成化学》2003,11(6):540-543
用β沸石分子筛作催化剂,对正丁酸与正戊醇的液-固相酯化反应进行了研究,考察了催化剂用量、β沸石中阳离子的类型、醇酸摩尔比、反应时间、带水剂环己烷的用量和催化剂活化时间对正丁酸转化率及丁酸戊酯产率的影响,提出了无催化剂及以Al-β沸石分子筛为催化剂时的酯化反应动力学模型。  相似文献   

5.
硫酸铈(Ⅳ)催化合成丁酸丁酯   总被引:7,自引:2,他引:5  
丁酸丁酯被广泛应用于食品、医药、烟草、日用化学工业 ,目前工业生产方法以浓硫酸催化丁酸和丁醇反应为主[1] 。由于浓硫酸的脱水、氧化作用 ,使得产物色泽深 ,产率低 ;而且硫酸易腐蚀设备 ,产品后处理产生的酸性废水严重污染环境。因此人们在努力寻找浓硫酸催化法的替代方法。用对甲苯磺酸、杂多酸为催化剂[2 4 ] 对合成丁酸丁酯具有很好的催化效果 ,但存在反应时间长、原料用量大等问题。本文以结晶硫酸高铈为催化剂合成了丁酸丁酯。1 实验部分1 .1 仪器与试剂岛津GC 1 6A气相色谱仪 ,FTS 2 1 0 0型红外光谱仪(美国Bio Ra…  相似文献   

6.
硫酸氢钠催化合成丁酸异戊酯   总被引:10,自引:1,他引:9  
丁酸异戊酯有类似梨的水果香气 ,广泛应用于溶剂、日用香精和食用香精中[1,2 ] .目前 ,工业上主要采用硫酸催化丁酸和异戊醇酯化法来合成[3] ,为克服硫酸催化法的缺点 ,改善合成环境 ,人们曾研究过采用结晶氯化铁、超强酸及杂多酸等催化合成丁酸异戊酯[4~ 6] ,然而结晶氯化铁很易吸潮、难于保管和准确使用 ,超强酸和杂多酸需要制备 ,成本较高 .本文选用的硫酸氢钠 (NaHSO4 ·H2 O)是一种价廉易得的无机酸性晶体 ,易保管且使用方便 ,催化效果好 ,同时它又不溶于有机反应体系 ,具有一定的重复使用性能 ,至今未见用NaHSO4 ·H2 …  相似文献   

7.
1引言正丁酸是一种重要的精细化工原料,主要用于制造丁酸纤维素和合成丁酸酯,其酯类在香料、食品添加剂、医药等领域有广泛的应用。反应物中除目的产物外,尚有少量丙酸、丙醇以及丁酸丙酯等副产物,但其分析方法未见有报道,因此开发一种有效的分析方法,不仅可为科研过程及时提供准确的实验结果和指导该工艺合成研究,并可为该产品的工业化生产提供可靠的分析测试手段。2仪器与试剂正丁酸、丙醇、丙酸皆为分析纯试剂,含量均大于99.5%;正丁醛是含量为99.46%的工业品;醋酸丁酯是含量为e.刀%的工业品。采用MO)气相色谱…  相似文献   

8.
对甲苯磺酸催化合成丁酸丁酯的研究   总被引:13,自引:0,他引:13  
丁酸丁酯是无色至淡黄色透明油状液体,有成熟香蕉似水果香气.稀释时为菠萝和朗姆酒香气及稀奶油滋味.天然品存在于苹果、香蕉、葡萄、梨、草莓、李、西番果等中.主要用以配制苹果、香蕉、梨和奶油等型香精,是我国GB2760-86规定允许使用的食用香料;也可用于有机合成和用作溶剂.通常它是在硫酸催化下由丁酸和正丁醇酯化反应而得[1-2],硫酸虽活性高,价廉,但选择性差,产品质量不好,设备腐蚀严重,同时产生大量废液,污染环境.因此人们寻求更优良的催化剂来代替硫酸,已发现强酸性阳离子交换树脂、磺酸树脂、固体超强酸、杂多酸以及过渡金属硫酸铜、氯化铁等均可作为酯化反应的催化剂[3-8].但用固体酸催化合成丁酸丁酯至今未见报道.对甲苯磺酸是一种强有机酸,无氧化性,无碳化作用,作为酯化反应的催化剂时,具有活性高,选择性好,产品纯度高,不腐蚀设备,减少污染等优点[9-10].本文利用对甲苯磺酸作催化剂合成丁酸丁酯,讨论了影响反应的因素,在适当的合成条件下,酯化率可达97.8%.  相似文献   

9.
建立了一种反相高效液相色谱方法,分离C60、其衍生物[6,6]苯基C61-丁酸甲酯和[5,6]苯基C61-丁酸甲酯及二加成物,并测定其中[6,6]苯基C61-丁酸甲酯的含量。采用C18柱(3μm,2.1×100 mm),以V(CHCl3)∶V(乙腈)=30∶70溶剂为流动相,流量0.15 mL/min,柱温35℃,检测波长350 nm,25min内即可将各种组分分离。采用外标法测定其中[6,6]苯基C61-丁酸甲酯的含量。该方法快速、简便、准确,可用于定量分析[6,6]苯基C61-丁酸甲酯。  相似文献   

10.
氨磺酸催化合成丁酸丁酯的研究   总被引:17,自引:1,他引:16  
林进  赵汝琪 《合成化学》2000,8(4):364-366
以氨磺酸为催化剂催化合成了丁酸酯,确定了酯优化条件。实验结果表明:在酸用量为0.2mol,醇酸摩尔比值为1.8,催化用量1.0g,带水剂甲苯15mL,反应时间2.0h,反应温度110℃-130℃的最佳反应条件下,酯化率为98.2%。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

16.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

17.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

18.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

19.
20.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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