去硝作用

The first synthetic route uses 1,2,4-trimethoxybenzene and chloroacetonitrile in forming 2,4,5-trimethoxy-a-chlor-acetophenone under the anhydrous condition, then the intermediate condensates with papaverine forming the core pyrro[2,l-a]isoquinoline, followed by formation and lactonization to form the lactone ring. The second synthetic route uses prepared aldehyde with prepared ethyl nitroacetate by Knoevenagel condensation to obtain 2-Nitro-3-(2,4,5-tris-methoxy-phenyl)-acrylic acid ethyl ester and 2-Nitro-3-(2,4,5-tris-benzyloxy -phenyl)-acrylic acid ethyl ester etal intermediates. The lamellarin skeleton could arise from condensation of the papaverine and these intermediates by Michael reaction, the ester group is provided for subsequent lactonization. The third synthetic route uses coumarin or indan-l,3-dione derivatives and papaverine to form lamellarin under basic conditions.

第一条路线首先从1，2，4-三甲氧基苯出发与卤乙腈作用合成卤代芳酮中间体，然后与罂粟碱反应合成开链片螺素，最后经乙酰化、去保护、成内酯环得到片螺素；第二条路线由制备的芳醛和制备的硝基乙酸乙酯经缩合得到2-硝基-3-芳基丙烯酸乙酯，然后由该中间体与罂粟碱反应，在完成关环的同时也引入酯基，最后去保护、成内酯环得到片螺素；第三条路线是由香豆素或茚二酮出发，经溴代后的中间体与罂粟碱反应，得到片螺素的基本框架。

The reasons of iron ions content overproof in grade Ⅱ desalting water system,such as variation water quality,contamination of regenerant , operation adjustment of pretreatment system and switching operation of bed were discussed.

对二级脱盐水系统中铁离子含量超标的原因，如来水水质发生波动、再生剂受到污染、预处理系统操作调整、床体运行切换等进行了论述。

You were hired to drum up new business, so go and do it.

公司雇你招徕新业务，你就做你的事好了。