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1.
微波合成SrTiO3的工艺、结构与性能研究   总被引:8,自引:1,他引:8  
应用微波会成这一材料合成新方法制备SrTiO3,研究了不同工艺条件下微波合成产物的结构,确定出制备纯净SrTiIO。的合成条件.对微波合成的工艺及其影响因素进行详细的探索,从合成产物的显微结构、粒度分布、比表面积、烧结性能等方面比较了微波合成与常规固相合成的差别,结果表明微波合成与各种常规方法相比有合成时间短、合成工艺简单、合成产物性能好等特点,是一种有发展潜力的材料合成技术.  相似文献   

2.
超低粘度羧甲基纤维素的合成   总被引:1,自引:0,他引:1  
用竹浆纤维合成了超低粘度羧甲基纤维素,并对合成工艺条件进行了讨论。  相似文献   

3.
利用热释发光谱和光激励发光谱表征了不同合成工艺条件对合成BaFBr:Eu^2 ,Al^3 发光性质的影响,利用理论分析找出了热释发光衰减与光激励衰减的异同,理论上计算了不同的合成工艺对BaFBr:Eu^2 ,Al^3 色心能级的影响,其热释发光谱和光激励发光谱的理论计算值能较好的吻合,并且能够很好的表征实验结果。  相似文献   

4.
采用正交设计试验研究了药典级DL-苹果酸的合成工艺。考察了反应物配料浓度、反应时间、反应温度等因素对转化率及选择性的影响。优化了合成工艺及精制方法,解决了达到药典级产品纯化的难题。  相似文献   

5.
以密胺-脲甲醛树脂合成的小试工艺条件为依据,完成了放大试验过程的工艺研究。研究结果与小试研究的工艺条件相吻合。  相似文献   

6.
阎世润  张志新 《合成化学》1996,4(2):122-127
介绍了FT合成烃类蜡的研究意义及从Schulz-Flory规律考虑高选择性合成蜡的可能性,重点介绍了Ru,Co,Fe等几种高选择性合成蜡的催化剂及其工艺条件,并对这几种催化剂进行了评述,参考文献29篇。  相似文献   

7.
异辛酸钒的合成研究与应用   总被引:4,自引:0,他引:4  
本文研究了异辛酸钒的合成,得出了合成异辛酸钒的最佳工艺条件,并比较了异辛酸钒和环烷酸钴对聚酯树脂固化的促进效果。实验结果表明,采用该工艺,可保证产品的质量,使钒的转化率达到99.9%以上,异辛酸钒的收率达到98.0%以上,与环烷酸钴相比,异辛酸钒促进剂具有使用数量减少,颜色浅,气味轻,粘度小等特点。  相似文献   

8.
乙二胺常压法合成哌嗪   总被引:6,自引:0,他引:6  
以乙二胺为原料,以K改性的H-ZMS-5型分子筛为催化剂,通过固定床反应器压法新工艺合成哌嗪,并对合成过程中的工艺条件参数进行了具体讨论。  相似文献   

9.
微波合成水杨酸异丙酯   总被引:9,自引:0,他引:9  
栗云天  尹应武 《有机化学》2002,22(10):750-753
研究了微波合成水杨酸异丙酯的工艺,与常规方法相对比,发现利用微波合成 水杨酸异丙酯具有反应速度快、转化率高、杂质含量小、后处理简单、无三废排放 等优点。  相似文献   

10.
聚乳酸的合成及分析   总被引:5,自引:0,他引:5  
采用间接开环聚合法合成了平均分子量为444,848的聚乳酸,并对合成工艺作了优化。用IR对所得单体丙交酯和聚乳酸进行了结构分析,结果表明,丙交酯和聚乳酸的谱图中各官能团十分明显。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

14.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

15.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

16.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

17.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

18.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

19.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

20.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

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