合成

After the diazotization, a mixture of 2,3,5-trichloropyridine and 3, 5- dichloropyridine-2-ketone was got as a result of Sandmeyer reaction.

收率达84.7%。接着，我们以制得的2，3，5-三氯吡啶为合成2，3-二氟-5-氯吡啶的原料，用NMP为溶剂，加入KF和CsF的混合氟化剂，高温下反应合成了2，3-二氟-5-氯吡啶。

Chapter two: Using 5-(4-aminophenyl)-10,15,20-triphenylporphyrin as thestarting compound, the classical diazotization of aniline and the resulting reaction ofdiazo salts were applied to porphyrin for the first time, and a series of asymmetriclysubstituted meso-tetraarylporphyrins including 5-(4-chlorophenyl)-10,15,20-triphenylporphyrin, 5-(4-iodinphenyl)-10,15,20-triphenylporphyrin, 5-(4-cyanophenyl)-10,15,20-triphenylporphyrin, 5-(4-bisphenyl)-10,15,20-triphenylporphyrin and 5-(4-hydroxylphenyl)-10,15,20-triphenylporphyrin were synthesized.

第二章：在已合成的5-(4-氨基苯基)-10，15，20-三苯基卟啉基础上，首次将芳胺的重氮化及重氮盐反应应用于卟啉，合成了5-(4-氯苯基)-10，15，20-三苯基卟啉、5-(4-碘基苯基)-10，15，20-三苯基卟啉、5-(4-氰基苯基)-10，15，20-三苯基卟啉、5-(4-联苯基)-10，15，20-三苯基卟啉和5-(4-羟基苯基)-10，15，20-三苯基卟啉等一系列不对称取代的meso-四芳基卟啉。

Thenew route has some advantages such as simple operation, inexpensive materials andbetter yield compare to other synthesis routes.The synthesis route is showed as follows. First,-2-chloro-3-phenylpropionic acid is synthesized from L-phenylalanine by diazotization.

在参考大量文献的基础上，我们设计了一条新的合成路线，和其它合成路线相比较本路线具有操作简单、原料易得、收率较高等优点。

With the developing of technology of computer and digital signal processing, speech synthesis has had application in many areas.

语音合成已经有两百多年的历史，随着计算机技术以及数字信号处理技术的发展，语音合成技术已经开始应用于各个领域。

In this paper, Claisen condensation of isochroman ?4?one as starting material with diethyl oxalate is carried out to form β?diketone compound of isochroman ?4?one.

以异色满酮 4为起始原料，经Claisen缩合得其β二酮衍生物，再与水合肼进行Knorr反应环合成 3 乙氧甲酰基和 3 肼甲酰基异色满并吡唑衍生物，通过酰肼与糠醛反应成腙后，分别与巯基乙酸和氯乙酰氯反应合成了标题化合物

When formaldehyde:dimethylamine is 2:1,the temperature of reaction is 55oC and the time of reaction is 2h, the ratio of production is the highest.

单体合成中探讨了羟甲基二甲胺的合成工艺，当甲醛：二甲胺为2：1，反应温度为55oC，反应时间为2h时，羟甲基二甲胺的收率最高；并通过NMR确定了其结构。

In this synthetic system, the central metal coordinated withSchiff base and chiral diol simultaneously, and a "mix-ligands complex" type chiral synthonformed.

在该合成体系中，四价的中心金属同时与氨基酸酯Schiff碱和手性二醇配位，形成了一个"手性合成子"。

In this research, two derivatives of the dipeptide Ala-Phe were synthesized in frozen aqueous systems in the yield of 95% and 89%, while the yields were 20% and 16% in aqueous solutions at room temperature.

在-20℃，两个Ala-Phe衍生物的合成产率可分别达到95%和89%；而在25℃，相应的肽合成产率则分别为20%和16%。

In this design, we used the digital direct synthesis method to complete the frequency synthesis.

本设计中，我们采用了数字直接合成的方法来完成频率合成。

In this paper, one spacer- armed analogue of a disaccharide SM_3 was synthesized for the first time via multi-step synthetic method.

本文经过11步反应，首次合成了带连接臂的SM_3寡糖链，为今后合成具有更高分子量的糖基缀合物并研究其抗肿瘤免疫原性奠定了基础。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失