查询词典 hydroxy acid

During the manufacturing of the critical intermediate cephalosporin nucleus --7-amino-3-chloro-cephalosporanic acid diphenylmethyl ester hydrochloride salt, first the feasibility of the one-pot synthetic route of open loop, closed loop and ozonization when chlorine is passed over is qualified by experiments. Then the critical factors that will influence this reaction are studied as follows: the mol ratio of triphenyl phosphite and Diphenylmethyl 3-hydroxy-7-phenylacetaminoceph-3-em-4-carboxylate-l-oxide is four to one; the quantity of the stablizer should be at least more than two to one. The temperature of the system must be 25℃ when chlorine is passed over so that the hydrochloride can be precipitated to obtain cephalosporin nucleus of cefaclor--7-amino-3-chloro-cephalosporanic acid diphenylmethyl ester hydrochloride salt.

在制备关键中间体头孢母核7-氨基-3-氯头孢烷酸二苯甲酯盐酸盐时，先通过实验验证把开环、闭环、臭氧化三步在通入氯气时并为一锅煮的合成路线的可行性之外，又研究了影响该反应的几个重要因素：亚磷酸三苯酯与3-羟基-7-头孢烷-5-亚砜-2-甲酸二苯甲酯的摩尔比为4：1；稳定剂2-甲基-2-丁烯的用量至少大于2：1，通入氯化氢气体时体系温度在25℃时盐酸盐则能够顺利析出，获得头孢克洛的头孢母核—7-氨基-3-氯头孢烷酸二苯甲酯盐酸盐。

ABSTRACT Immobilized penicillin acylase (from E.coli) was used to catalyze 7 phenylacetamido 3 E propenyl cephalosporanic acid hydrolyzation into 7 amino 3 E propenyl cephalosporanic acid. Then, trans APRA was acylated with hydroxyethyl ester of 4 hydroxy D phenylglycine to obtain trans cefprozil.

以7 苯乙酰氨基 3 E 丙烯基 3 头孢菌素 4 羧酸为原料，在青霉素酰化酶作用下，首先酶法水解得到3 E 丙烯基 3 头孢菌素 4 羧酸，过滤固相酶，滤液调pH分离得到反式APRA固体；在青霉素酰化酶作用下，反式APRA再与对羟基苯甘氨酸乙二醇酯缩合，得到反式头孢丙烯；酶法合成所得的产品与进口反式头孢丙烯对照品一致。

It includes the following steps: polymerizing 2, 4-dihydroxyl metaphenylene diamine hydrochloride, diamine monomer and dipic acid anhydride to gain the polyimide that contains hydroxy on the molecule chain, making the hydroxyl take esterification reacting with acyl chloride and acrylic acid to gain polyimide photosensitive material that has negative photonasty.

该聚酰亚胺光敏材料以2，4-二羟基间苯二胺盐酸盐，二胺单体和二酸酐为原料进行聚合，得到分子链上含羟基的聚酰亚胺，然后使羟基与丙烯酸及其衍生物的酰氯发生酯化反应，得到具有负性感光性能的聚酰亚胺光敏材料。

In this work , 1,8-octodiol, the starting material, reacted with 40% hydrobromic acid to produce 8-bromooctan-1-ol, with the catalytic action of PPTs, its hydroxyl group was protected by 2,3-dihydropyran. Then it coupled with 1-heptaalkyne, by means of P-2 nickel as catalyst, stereoselectivity catalysis hydrogenated, with the catalytic action of acid to take off extremital 2, 3-dihydropyran which protected hydroxy group, then used PCC to oxidize alcohol into corresponding aldehyde.

以1，8-辛二醇为原料，与40%氢溴酸进行单溴代反应，得到8-溴-1-辛醇，在对甲苯磺酸吡啶盐的催化下与2，3-二氢吡喃反应，保护分子中的羟基，再与1-庚炔进行偶联，以P-2镍为催化剂立体选择性催化加氢，酸性条件下脱末端的2，3-二氢吡喃对羟基的保护，使用氯铬酸吡啶盐将醇氧化成醛。

Mandelic acid has the advantage of being a larger sized molecule compared to most other alpha hydroxy acids, including one of the more widely used ones, glycolic acid.

扁桃酸具有的优势，作为一个较大规模的分子相比，大部分其他α羟基酸，其中包括更广泛使用，乙醇酸。

Ethoxy-4-hydroxy mandelic acid was synthesized from glyoxylic acid and o-ethoxyphenol in alkaline solution.

在碱性条件下由乙醛酸和邻乙氧基苯酚合成了3-乙氧基-4-羟基苯乙醇酸。

They may contain long carbon chain with hydroxy or amino, unsaturated fatty acid, phenyl glucoside, mannitol, benzoic acid, isomaltose and galactose estimated by particular analyzed chart.

含有带羟基或氨基的长碳链、烯酸结构、异麦芽糖、β-D-苯基葡糖苷、甘露醇、苯甲酸和β-D-半乳糖成分。

The myristic-2-hydroxy-3-propane sulfonic acid sodium salt was synthesized from sodium bisulfite, epichlorohydrin, sodium phosphate and myristic acid. The influence factors of temperature, amount of catalyst, reaction time and reactant ratio on conversion were studied.

以亚硫酸氢钠、环氧氯丙烷、磷酸钠和肉豆蒄酸等为原料，合成了肉豆蒄酸－2-羟基－3-磺酸钠丙酯，探索了反应温度、催化剂、反应时间、反应物物质的量比等因素对合成的影响。

By using gas chromatography technique nine kinds of fragrance components(acetic aldehyde,ethyl acetate,ethanol,propyl acetate,3-hydroxy-2-butanone,acetic acid,furfural,metacetonic acid,2,3-butylene glycol)were measured quantitatively in different kinds of Shanxi overmature vinegar and the other kinds of vinegar.

应用气相色谱方法对山西老陈醋和其他种类醋的9种香气成分(乙醛、乙酸乙酯、乙醇、乙酸丙酯、3-羟基-2-丁酮、乙酸、糖醛、丙酸、2，3-丁二醇)进行了定性、定量测定，并用聚类分析、模糊综合评判、方差分析、回归分析的方法对实验结果进行了数理分析。

Chloro-5,12-naphthacenequinone was synthesized from 2-(1-hydroxy-2-naphthyl)carbonylbenzoic acid by chlorination reaction using a mixture of phosphorus pentachloride and phosphorus oxychloride as a chlorating agent and then by ring-closing reaction using sulfuric acid as a dehydrating agent.

以2-[(1-羟基-2-萘基)羰基]苯甲酸为原料、五氯化磷/三氯氧磷为氯化剂进行氯化反应，然后用浓硫酸脱水环化，合成了6-氯-5，12-萘并萘醌，优化了反应条件，总收率达68.2%。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。