薄层色谱法在香兰素合成中的应用

应用薄层色谱法对愈创木酚、3－甲氧基－4－羟基扁桃酸和香兰素进行了分析，以硅胶GF254作为吸附剂，从几种溶剂系统中选出氯仿：乙酸乙酯：正丙醇：冰乙酸：水＝20：1：1：1：2溶液作为展开剂。建立了 香兰素的薄层扫描定量分析方法，测定波长为500nm，参比波长为570nm，线性范围为0．31－6．2μg。     

反相高效液相色谱法测定人血浆中利培酮及其代谢物的质量浓度

建立了测定人血浆中利培酮及其活性代谢物9-羟利培酮质量浓度的反相高效液相色谱方法。用Zor－baxODSC18色谱柱,以V（甲醇）：V（水）：V（1mol／L醋酸铵）：V（3mol／L氨水）＝300：50：3：1为流动相,检测波长为280nm,流速为0．8mL／min。利培酮的线性范围为2～600μg／L（r＝0．996）,回收率为（98．2±3．5）％,日内与日间的标准偏差分别为4．12％和4．83％;9-羟利培酮的线性范围为2～800μg／L（r＝0．998）,回收率为（97．8±3．8）％,日内与日间的标准偏差分别为4．28％和4．81％。     

土壤中多种有机氯及拟除虫菊酯类农药的GC-ECD测定

气相色谱法同时测定土壤中多种有机氯及拟除虫菊酯类农药。对土壤的分析结果：有机氯农药的检出限0．001～0、003μg／mL，拟除虫菊酯类农药检出限0.008～0．02μg／mL，线性相关系数0．9978～0．9999。用y（石油醚）：V（丙酮）=3：1超声波提取，有机氯农药回收率94．2％～124．0％，相对标准偏差为3．3％～8．8％（n=5）；拟除虫菊酯类农药回收率95．2％～118．3％，相对标准偏差为5．7％～7．1％（n=5）；方法适用于土壤样品中农药残留测定。     

测定血浆中微量硒的三元包合物荧光分析法

采用氧瓶燃烧法对血样进行破坏,利用β－环糊精和十二烷基硫酸钠形成包合物的性质,将4,5－苯并苯硒二唑包合,建立了三元包合物荧光分析法,不经萃取,直接测定血浆中的硒。方法的日内精密度为5．4％－9．3％（n＝7）;日间精密度为3．5％－14．5％（n＝7）;线性范围为10－500μg／;回收率为91．0％－97．8％。对新疆汉族、维吾尔族和沈阳汉族58人的血样进行测定,结果表明：新疆汉族与沈阳汉族间血硒值无显著性差异（F＝1．36,P＞0．05）;新疆汉族与维吾尔族间血硒值有非常显著性差异（F＝1．01,P＜0．01）;男女之间血硒值有非常显著性差异（P＜0．01）。     

单扫描极谱法测定果、蔬中有机磷农药残留量

提出了在0．40mol/L氢氧化钠底液中对碱解后的有机磷农药进行单扫描极谱测定的方法。于起始电位－0．30V（vs SCE)进行阴极化扫描时有产生一灵敏导数波,峰电位为－0．53V（vs SCE)。并获得了辛硫磷残留量检测的最佳条件。在此条件下检测有机磷农药的线性范围分别为：辛硫磷0．12－160μg/mL,甲基对硫磷0．5－200μg/mL,水胺硫磷0．20－160μg/mL,甲胺磷0．1－1．0ng/mL,氧化乐果0．09－160μg/mL。     

吡虫啉极谱吸附波的研究及应用

在0．04mol/LNH3－0．2mol/LNH4Cl（pH＝8．0）的介质中,吡虫啉在单扫描极谱仪上于-0．95V（vs,SCE）处产生一灵敏的吸附还原波,其浓度在1．2×10－4~5．0×10-6mol/L之间与峰电流呈良好的线性关系（r＝0．9941）。对于4．0×10-5mol/L吡虫啉,平行测定（n＝6）的RSD为1．38％,回收率为100．0％~101．1％。建立了单扫描极谱测定吡虫啉的新方法,该法对吡虫啉工业品进行测定取得满意的结果。同时对电极反应机理进行了研究。     

薄层色谱法定量测定氮酮

对薄层色谱法测定氮酮的操作条件进行了探索。选择了以丙酮为溶剂对样品进行溶解，以石油醚-异丙醚-异丙醇(体积比6：1：1)为展开剂上行展开，在碘蒸汽中显色，密封展板后进行测量。甚定性检测结果各组分分离良好，斑点集中且清晰。定量检测线性范调为15～250μg，线性方程Y(μA)=869．7514 101．9879X(μg)(n=8)，相关系数为0．9986，加标回收率为101．2％，仪器精密度为1．21％，同板精密度为1.82％，均满足薄层定量分析的要求。     

α—卤代萘与叔已酮碳负离子在Co（Ⅱ）络合物催化下的自由基链式亲核取代反应产物的薄层色谱定量分析

研究了以Co(Ⅱ）络合物为催化剂，α－卤代萘与叔已酮碳负离子的自由基链式亲核取代反应（SRN1）产物α－萘基叔已酮的薄层色谱扫描定量分析方法；定量分析的弭性范围为0－4．4μg，平均回收率99％－101％，异板间相对标准偏差为2．3％，同板相对标准偏差为1．6％。     

高效液相色谱法对吗啡、杜冷丁、安定的同步测定

利用高效液相色谱法同时分析测定了血液中吗啡、杜冷丁、安定的质量浓度。分析柱为C18,流动相为V（甲醇）：V（25mmol／LKH2PO4）＝90：10,检测波长为285nm。样品血液pH8．5～9．4时,用V（氯仿）：V（异丙醇）＝9：1溶液提取,以氮气吹干有机溶剂后用流动相溶解残渣进样分析。线性范围为0．05～50mg／L,最小检出质量浓度为0．05mg／L,日内与日间精密度CV＜6％。     

Co_3(CO)_7(μ_3-S)[μ, η~2-SCNC (O)C (R_1) (R_2)N (COR_3)]的合成和晶体结构

Co2（CO8）分别与4种硫代乙内酰脲S＝CNHC（O）C（R1）（R2）N（COR3）反应，得到4个新的含硫代乙内酰脲桥基双齿配位的三核钴羰基硫簇合物．用元素分析、IR、1HNMR和MS等手段表征了它们的结构，用X射线衍射测定了其中一个簇合物CO3（CO）7（μ3－S）［μ，η2－SCNC（O）C（CH3）（CH3）N（COCH3）］（IV）的晶体结构，晶体属三斜晶系，P1空间群，晶胞参数：a＝0．8456（3）nm，b＝1．1534（3）nm，c＝1．1990（4）nm；a＝107．36（3）°，β＝108．44（5）°，γ＝90．18（3）°；V＝1．052（6）nm3，Z＝2，F（000）＝584，Dc＝1．86g／cm3，μ＝25．71cm－1，最终偏离因子R＝0．046，Rw＝0．058．     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.