乙二酰脲

Methoxycarbonyl-4-(4-methoxyphenyl )-6-methyl-3, 4-dihydropyrimidine-2(1H)-one was synthesized from anisaldehyde, methyl acetoactate and urea in presence of HF-1O1 strong acidic ion-exchange membrane.

在HF-101强酸性离子交换膜的存在下，由对羟基苯甲醛、乙酰乙酸甲酯与脲一步合成了5－甲氧羰基－4－（4－甲氧苯基）－6－甲基－3，4－二氢嘧啶－2(1H)－酮。

New compounds of the type of N--N'-(2,4-dichlorophenyloxyacetyl)-semicarbazides were synthesized by a series of reactions of preparing organic isocyanates by Curtius rearrangement with 2,4- dichloro aryloxyacetic acid hydrazide using one-pot procedures.

以芳香取代酸为原料，用Curtius重排的方法合成异氰酸酯，直接与2，4-二氯苯氧乙酰肼作用，一锅法合成了4种N-取代芳基-N'-(2，4-二氯苯氧乙酰基)氨基脲类化合物。

Benzyloxy benzoyldimethylsulfoxide was prepared by the reaction of ethyl 4-benzyloxybenzoate and dimethyl sulfoxide in the presence of sodium hydride, followed by Pummerer reaction with concentrated hydrochloric acid to afford eo-hydroxy-co-thio-methyl-(4/-benzyloxy) acetophenone, which reacted with urea, thiosemicarbazide, semicarbazide hydrochloride and o-phenylenediamine to give imidazolidine-2,4-dione, l,2,4-triazine-3- one and quinoxaline derivatives, respectively.

本文用4-苄氧基苯甲酸乙酯和二甲亚砜为原料，在氢化钠存在下反应，合成了(4′-苄氧基)-苯甲酰基-二甲亚砜。研究了该亚砜在浓盐酸的存在下发生的Pummerer重排反应，用重排产物ω-羟基-ω-甲硫基-(4′-苄氧基)-苯乙酮分别与尿素、氨基脲、氨基硫脲和邻苯二胺反应合成了2，4-咪唑啉-二酮、1，2，4-三嗪-3-酮、喹喔啉等含氮杂环化合物。

Methacryloyloxydecyl-2-thiouracil-5-carboxylate was synthesized from the reaction of thiouracil with diethyl ethoxymethylene malonate and ω-hydroxy-decyl-methacrylate.

以硫脲、乙氧基次甲基丙二酸二乙酯和甲基丙烯酸ω-羟癸酯为主要原料合成了一种新的粘接性单体10-甲基丙烯酰氧癸基－2-硫脲嘧啶－5-羧酸酯。

In order to find biologically active urea compounds,seven new N-[5-(3-pyridyl)-1,3,4-thiadiazol-2-yl]-N'- urea derivatives were synthesized by the reaction of 2-amino-5-(3-pyridyl)-1,3,4-thiadiazole with aroylazides,which were prepared starting from carboxylic acids,ethyl chloroformate and sodium azide by one-pot procedure.

为了寻找高生物活性的脲类化合物，通过2-氨基-5-(3-吡啶基)-1，3，4-噻二唑与酰基叠氮化物反应，设计合成了7个新的N-[5-(3-吡啶基)-1，3，4-噻二唑-2-基]-N'-取代苯基脲，其中芳酰基叠氮化物是以芳酸、氯甲酸乙酯、叠氮化钠为起始原料采用&一锅法&所制得。

Two novel pyrazolone derivatives 2-ethylamino-6H-5-(1-phenyl-3-methyl/phenyl-5-pyrazolone-4-ylene)-1,3,4-thiadiazine (PMCP-ETSC/DPCP-ETSC) containing NNS six-membered heterocycles were synthesized by the condensation reaction of 1-phenyl-3-methyl/phenyl-4-chloroacetyl-pyrazolone-5 with 4-ethyithiosemicarbazide. The title compounds were characterized by elemental analysis, IR, 1H NMR, 13C NMR and single-crystal X-ray diffraction.

利用1-苯基－3-甲基／苯基－4-氯乙酰基－吡唑啉酮－5与4-乙基氨基硫脲发生缩合反应，生成了2个新的双杂环化合物2-乙氨基－6H-5-（1-苯基－3-甲基／苯基－5-吡唑啉酮－4-基）－1，3，4-噻二嗪(PMCP-ETSC/DPCP-ETSC)，并对其进行元素分析、红外光谱、核磁共振表征和晶体结构分析。

The results showed 3 types of aluminum compound prepared in this paper all had good poison protection effectiveness on such impurities as stannous chloride,lead oxide,sodium hydrogen sulfate,and so on.Moreover,the mechanism of the poison of catalyst was also discussed.

结果表明，合成的3种防中毒剂即防－1、防－2(主要成分为乙酰丙酮合铝)及防－3(主要成分为二乙酰丙酮基异丙氧基铝)对二月桂酸二丁基锡、氯化亚锡、二正丁胺、硫脲、氧化铅及硫酸氢钠等杂质均有较好的防中毒作用；不同防中毒剂对不同杂质的防中毒作用有一定的选择性。

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。