异丙基苯

With L-DOPA as the starting chiral phenylalanine derivatives, construction of the skeleton of Phthalascidin was studied. Firstly, starting from L-DOPA and 3,4-dimethoxyphenylalanine, an amide 〓 was obtained, and a modeling cyclization reaction was carried out but failed to give the anticipated product.

二、对由苯丙氨酸甲酯衍生物通过Bischler-Napieralski反应合成四氢异喹啉—3—甲酯进行了研究，通过研究首次发现，生成苄基噁唑的反应是正常的B-N反应的竞争性反应，并从机理上给予了解释，所得出的结论具有一定的规律性，在杂环的合成方面具有一定的应用价值。

The major products were methane, ethylene, propylene, butylene, butadiene, cyclopentadiene, benzene, toluene, styrene, vinyl-substituted cyclopentene derivatives and C5/C6 isomers pentadiene, met...

热裂解主要产物为甲烷、乙烯、丙烯、丁烯、丁二烯、环戊二烯、苯、甲苯、苯乙烯、环戊烯的乙烯基取代物及C5，C6异构体(戊二烯、环戊烯的甲基取代物、环己烯、己二烯和环戊二烯甲基取代物)，其中，C1～C4、环戊二烯、苯、甲苯、乙烯基取代环戊烯为初始产物。

New compounds of the type of unsymmetrically substituted ureas are synthesized by a series of reactions of preparing organic isocyanates by Curtius rearrangement with aromatic amine.

以3 苯基 2 丙烯酸为原料，用Curtius重排的方法合成异氰酸酯，直接与芳香胺作用，合成了5 种N 取代苯基 N′苯丙烯基脲类化合物。

In the pharmaceutical aisles, I found 61 varieties of untan oil and sunblock , and 80 different pain relievers —aspirin, acetaminophen, ibuprofen; 350 milligrams or 500 milligrams; caplets, capsules, and tablets; coated or uncoated.

在药品的过道上，我发现有61种不同的untan 油和防晒霜，还有80种止痛药——阿司匹林，乙醯胺基酚，异丁苯丙酸，还分350毫克和500毫克；还有囊片，胶囊，药片，其中还分有有包裹层和没有包裹层的。

In this study, Japanese cedar, Ma bamboo and Makino bamboo were liquefied in polyethylene glycol/glycerol co-solvent with H2SO4 or HCl as catalyst. The liquefied woody materials were blended with PMDI (4,4'-Diphenylmethane diisocyanate;MDI) to prepare the PU foams. The effects of preparation conditions of PU resin on the properties of PU foams were investigated.

中文摘要本研究将柳杉(Cryptomeria japonica； Japanese cedar)、麻竹(Dendrocalamus latiflorus； Ma bamboo)及桂竹(Phyllostachys makinoi； Makino bamboo)等木质材料以聚乙二醇及丙三醇之混合液为溶剂，H2SO4及HCl为催化剂进行液化处理，并将其液化木质材料与4，4'-二苯甲烷二异氰酸酯反应制造聚胺基甲酸酯发泡体，探讨PU树脂调配条件对PU发泡体性质之影响。

Now, however, all children continue in "comprehensive" schools, and the eleven-plus determines which courses of study the child will follow.

然而现在，所有的孩子都要在综合学校继续学习，所以这次考试只是决定他们将要学习哪些课程。

Cultivatable land , and led to a general recognition that development must not be carried at the cost of agriculture .

城区的迅速扩大在很多情况下侵占了宝贵的可耕地，使人们普遍认识到发展不能以牺牲农业为代价。