Synthesis of (1H)-3,4-Dihydropyrrolo[2,1-c][1,4]oxazin-1-one Derivatives

It has been found that some acyl derivatives of 1,2,3,4-tetrahydro-1-indolizin-1-one 1and (1H)-3,4-dihydropyrrolo[1,2-a]pyrazin-1-one 2 show remarkable anti-inflammatory and analgesic activities1,2. The interest in extending the study of structure-activity relationships and search of new potent anti-inflammatory and analgesic agents led us to design and synthesize (1H)-3,4-dihydropyrrolo[2,1-c][1,4]oxazin-1-one 3 derivatives. NO 1 NNHO2 87654321ONO3 A few examples of the p…     

Simultaneous Determination of Gold and Platinum by Double Artificial Neural Network Analysis with Flow-injection Chemiluminescence

Chemiluminescence (CL) is well known to be an important and powerful analytical technique owing to its lower detection limits, higher sensitivity and wider linear ranges can be achieved with simpler instrument1. CL analysis has been used for determination…     

Synthesis,Structure,Characterization and Electrochemistry of a New Dinuclear W(0)-complex 〔Et_4N〕_2〔W_2(CO)_8(SCH_2COOMe)_2〕

１ＩＮＴＲＯＤＵＣＴＩＯＮＲｅｃｅｎｔｌｙ,ｔｈｅｃｈｅｍｉｓｔｒｙｏｆｃｏｍｐｌｅｘｅｓｃｏｎｔａｉｎｉｎｇｌｏｗ ｖａｌｅｎｃｅｍｅｔａｌａｔｏｍｓｈａｓｉｎｃｒｅａｓ ｉｎｇｌｙａｔｒａｃｔｅｄｔｈｅａｔｅｎｔｉｏｎｆｒｏｍｃｈｅｍｉｓｔｓａｎ...     

激光诱导击穿光谱结合偏最小二乘法定量分析脐橙中Cd含量

基于激光诱导击穿光谱(LIBS)技术对赣南脐橙中Cd元素进行定量分析. 利用LIBS获取样品中Cd元素的特征谱线信息, 并结合原子吸收分光光度计测量样品中Cd元素的真实含量.采用五点平滑法和中心化法对样品光谱数据进行预处理, 基于偏最小二乘法(PLS)对其中的39个样品建立Cd元素的定量分析模型, 在该模型的基础上预测另外13个样品的Cd含量, 并对PLS模型进行对比验证. PLS模型中拟合曲线的相关系数为0.9806, 12个样品的验证结果的相对误差为10.94%.研究结果表明, 激光诱导击穿光谱技术能够准确的检测农产品中重金属含量, 为农产品的安全检测提供技术方法. 关键词： 激光诱导击穿光谱 Cd 定量分析 偏最小二乘法     

New Diterpenoid Alkaloids from Spiraea japonica var. Ovalifolia

In the investigation of the chemical constituents of Spireae japonica L. f. var. ovalifolia (Rosaceae), a shrub originated in Songming, Yunnan, five new diterpenoid alkaloids, 19-O-deethylspiramine N (1), deacetylspiramine S (2), spiramidine A (3), spiramidine B (4) and deacetylspiramine F (5), were isolated from aerial parts of the plant and structurally elucidated. Compound 1, a white amorphous powder with [(]+17.99 (c, 0.26, MeOH ), was determined to have the molecular formula of C20H…     

Structures that should be Described in Higher-Symmetry, Centrosymmetric Space Groups. Part 2. The Structures of [Ni(C_5H_4NO-2-CH=N-CH_2CH_2-N=CH-2-C_5H_4NO)(H_2O)_2]- (ClO_4)_2, {Ni[C_5H_4NO-2-CH=N-CH(CH_3)CH_2-N=CH-2- C_5H_4NO](H_2O)_2}

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｅｖｅｒａｌｉｎｃｏｒｒｅｃｔｓｐａｃｅｇｒｏｕｐｓｈａｖｅｂｅｅｎｒｅ ａｓｓｉｇｎｅｄｂｙｍａｋｉｎｇｕｓｅｏｆｓｉｍｕｌａｔｅｄｓｔｒｕｃｔｕｒｅｆａｃｔｏｒｓ;ｈｏｗｅｖｅｒ,ｔｈｅｃｒｕｘｏｆｔｈｉｓｏｒａｎｙｓｐａｃｅｇｒｏｕｐｒｅｖｉｓｉｏｎｉｓｔｈｅａｃｃｕｒａｔｅｒｅｐｏｒｔｉｎｇｏｆｔｈｅｓｐａｃｅｇｒｏｕｐａｎｄａｔｏｍｉｃｃｏｏｒｄｉｎａｔｅｓｏｆｔｈｅｉｎｃｏｒｒｅｃｔｌｙｄｅｔｅｒｍｉｎｅｄｓｔｒｕｃｔｕｒｅｓｉｎｃｅｔｈｅｔｒｕｅｓｔｒｕｃ…     

A New Indole Alkaloid from Limonia Crenulata

Limonia crenulata Roxb. (Rutaceae), a small tree widely distributed in dry warm regions of southeastern Asia, has been reported to have antiepileptic, purgative and sudorific effects and is used for colic trouble and cardialgia1. Various parts of this plant have been employed in indigenous medicine. Our investigation on its stems led to the isolation of one new alkaloid, crenulatine 1, together with three known ones, 4-methoxy-6- hydroxy-1-methyl-2-quinolone2, N-benzoyltyramine methyl ether2,…     

A Novel Synthesis of Dimethyl Malonate by Carbonylation of Methyl Chloroacetate Catalyzed by Cobalt Complex

Dimethyl malonate (DMM) is an important organic synthesis intermediate. Traditional synthetic method by reaction of mono-chloroacetic acid with sodium cyanide1 is poisonous and complicated. Therefore, an interest in green synthesis routes of DMM has risen greatly. The several processes for preparing DMM by carbonylation of methyl chloroacetate catalyzed by Co2(CO)8 have been reported2~5. However, Co2(CO)8 is unstable and must be prepared under high pressure (12 Mpa). Moreover, the yield…