Theoretical Study on the Reaction Mechanism of o-Aminophenol, Acetic Acid and Phosphorus Oxytrichloride One-pot to Form 2-Methyl Benzoxazole

The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol^(-1) and the reaction heat being 10.06 kJ·mol^(-1). The dominant product predicted theoretically is in agreement with the experiment results.

Synthesis and Molecular Structure of (E)-1- (Morpholino)-2-(thiomethyl)-2-phenylvinylphosphonate

The title compound 2 (C15H22NO4PS, Mr = 343.38) was prepared by the reaction of α-benzoylthioformmorpholine 1 with trimethyl phosphite. The crystal is of monoclinic, space group P21/c with a = 14.906(2), b = 8.4711(12), c = 13.343(2) ?, β = 96.761(4)o, Z = 4, V = 1673.1(5) ?3, Dc = 1.363 g/cm3, μ(MoKα) = 3.06 cm-1, F(000) = 728, the final R = 0.0590 and wR = 0.1740 for 3036 observed reflections (I > 2σ(I)). X-ray analysis revealed that the interatomic distance of C(5)–C(6) is 1.353(4) ?, indicating it is a normal C=C double bond. The P(1) atom takes a distorted tetrahedral geometry, and the morpholine ring adopts a chair conformation. The morpholino group is located at the 1-position of vinylphosphonate, and the phenyl and thiomethyl groups at the 2-position.

An Efficient Process for Preparing 4-Methyl-2-phenyl Piperazine Hydrochloride and its Derivatives

An improved method for preparation of 4-methyl-2-phenyl piperazine and its derivatives with higher yield and inexpensive reagents was developed, the products were characterized by 1H-NMR and MS.

Synthesis, Crystal Structure and Quantum Chemistry of Tris[(2-methyl- 2-phenyl)propyl](2,4-dinitro-phenolato)tin

The tris[（2-methyl-2-phenyl）propyl]（2,4-dinitro-phenolato）tin was synthesized by the reaction of bis[tri（2-methyl-2-phenyl）propyltin] oxide with 2,4-dinitrophenol. The compound was characterized by IR, 1H NMR spectra and elemental analysis. The crystal structure has been determined by X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/n with a = 0.9649（0）, b = 1.0087（8）, c = 3.4867（4） nm, β = 90.965（7） , Z = 4, V = 3.3933（7） nm3, Dc = 1.369 Mg·m-3, （MoKa） = 0.796 mm-1, F（000） = 1440, R = 0.0345 and wR = 0.0821. The tin atom has a distorted tetrahedral geometry. The 2D network structure of the complex is formed by hydrogen bonds and π-π effects. The stabilities, orbital energies and composition characteristics of some frontier molecular orbitals of the complexes have been investigated with the aid of G98W software.

A Novel Fluorescence Probe 9-(4-(1,2-diamine)benzeneN^1-phenyl)acridine for Nitric Oxide Determination

A novel fluorescent probe 9-（4-（1,2-diamine）benzene-N1-phenyl）acridine（DABPA） was synthesized for the detection of nitric oxide（NO） and characterized by IR, 1H-NMR and EI-MS spectroscopy. Based on a photoelectron transfer mechanism, the fl uorescence intensities of DABPA were investigated with the different concentrations of NO. Under the optimal experimental conditions, the fl uorescence intensity of DABPA had a good linear relationship（R2=0.9977） with NO concentration in the range from 1×10-7 to 1.5×10-6 mol/L with a detection limit of 1×10-8 mol/L. The cytotoxicity induced by DABPA was evaluated by the MTT（3-（4,5-dimethylthiazol-2-yl）-2,5diphenyl tetrazolium bromide） assay for biological application. Furthermore, the probe DABPA had also been successfully applied to real-time image NO produced in PC12 cells in the presence of L-arginine.

碱催化2-取代苯并噁唑类化合物合成

苯并噁唑是一类重要的含氮氧杂环化合物,具有良好的生物活性。苯并噁唑化合物中2位官能团对生理活性影响最大,因此,研究2-取代苯并噁唑类化合物的合成具有重要意义。以2-氨基苯酚为起始原料,在碱性条件下合成了5种2-取代苯并噁唑类化合物,产物结构经1HNMR确证。

2-取代苯并恶唑衍生物的合成及其在药物合成中的应用

2-取代苯并恶唑是一类重要的杂环骨架,其在药物合成中受到广泛关注与运用。本文以廉价易得的邻氨基苯酚和芳香醛为原料,通过一锅两步法优化第一步与第二步反应条件,确定第一步二氧六环为溶剂,室温空气气氛反应5h;第二步2,3-二氯-5,6-二氰基苯醌为氧化剂,室温空气气氛反应1h,氧化环化合成一系列2-取代苯并恶唑衍生物,同时将该方法运用于药物Tafamidis的合成中。目标化合物结构经^(1)H-NMR、^(13)C-NMR和HRMS确证。该方法条件温和、操作简便、底物普适性广以及具有一定的实用性,为2-取代苯并恶唑化合物合成提供了一种新的思路。

2-(1或2萘基)苯并噁唑的电子结构与光物理性质

本文用PPP-SCF-CI法对2-(1或2萘基)苯并噁唑及其Z、E同分异构体的电子结构及紫外光谱进行了理论研究,讨论了各分子的光谱特性,解析了对应于实验的不同异构体紫外吸收光谱,找到了该分子体系的主要生色团,理论计算与实验结果的偏差约在1%以内。这为深入研究苯并噁唑类分子的光物理性质、进一步预测具有更好性能的新型材料提供了理论依据。

2-苯基-1,3-苯并唑衍生物分子的非线性光学性质

2-苯基-1,3-苯并唑分子为母体,设计了一系列取代衍生物,研究了不同取代基,不同取代位置对分子电子结构及分子的非线性光学性质的影响。研究结果表明取代位置对分子的一阶极化率影响不太,对分子的二阶、三阶极化率影响较大,目标分子的二阶极化率与分子的(μe-μg)/ΔE2有较好的相关性。在母体分子的7、8位连接-NO2,13位连接-NH2得到的分子其分子的二阶极化率最大,而在7、8位连接-NH2,13位连接-NO2得到的分子具有最大的三阶极化率。

2-(2′-吡啶基)苯并噁唑和甘氨酸铜配合物的结构、抑菌活性及与DNA作用

本文以2-(2′-吡啶基)苯并噁唑、甘氨酸和高氯酸铜髤为原料合成了新的三元配合物:[Cu(PBO)(Gly)(H2O)]ClO4(PBO=2-(2′-吡啶基)苯并噁唑,Gly=甘氨酸根)。应用元素分析、红外光谱、紫外可见光谱、摩尔电导率等方法对配合物进行了表征。X-射线单晶衍射测得该配合物晶体属正交晶系,Pca21空间群,晶胞参数:a=1.029 2(2)nm,b=1.032 9(2)nm,c=1.566 8(3)nm;Z=4,V=1.665 6(6)nm3,Dc=1.800 g.cm-3,F(000)=916。最终偏离因子:R1=0.042 6,wR2=0.101 3。利用试管二倍稀释法测定了配合物的抗菌活性,通过电子吸收光谱、荧光光谱和粘度测定研究了配合物与DNA的作用。结果表明,与2-(2′-吡啶基)苯并噁唑相比较,该配合物对枯草杆菌(B.subtilis,G+),金黄色葡萄球菌(S.aureus,G+),苏云金芽孢杆菌(B.thuringiensis,G+),水稻条斑病细菌(X.oryzae,G-),大肠杆菌(E.coil,G-)和沙门氏杆菌(Salmonella,G-)具有良好的抑制活性,并且以插入方式与DNA作用。

用正交实验法优化5-氨基-2-(对氨基苯)苯并噁唑的合成工艺

以2,4-二氨基苯酚盐酸盐和对氨基苯甲酸为原料在多聚磷酸中合成了高纯度的5-氨基-2-(对氨基苯)苯并噁唑。用正交实验设计对该合成方法进行了研究,得出了最优化的反应条件:反应温度为200℃,反应时间5 h,P2O5质量分数为84%。产品产率较高,可达90%以上。并对产品的纯化方法进行了改进,用甲醇作为重结晶溶剂,得到的产品纯度达98%以上。产物可作为聚合反应的单体原料。

4,4′-双(苯并口恶唑-2-基)二苯乙烯荧光增白剂(OB-1)的合成

以对甲基苯甲酸及其乙酯为原料,经过三氧化铬在乙酐中的氧化反应、在氯苯溶剂中以氯化亚砜为氯化试剂的侧链氯化反应和亚磷酸三乙酯为乙基化试剂的酯化反应,再经两步缩合反应,合成了荧光增白剂4,4′ 双(苯并口恶唑 2 基)二苯乙烯(OB-1)。OB-1(由Ⅲ合成Ⅳ粗品)的收率由文献中平均90%提高到平均99%以上。通过对化合物的元素分析、红外光谱以及在DMF中紫外吸收光谱的测定,确定了目标产物的结构。经HPLC测定,w(OB-1)>99%。

2-甲基苯并恶唑的合成研究

以邻氨基苯酚和乙酸为原料合成2-甲基苯并恶唑,用正交试验得出优化合成条件:溴化四丁基铵(TBAB)为相转移催化剂,n(邻氨基苯酚)∶n(乙酸)=1∶1,反应温度为50℃,收率90.4%。此法原料易得,条件温和,操作简便,收率良好。

4-(2-苯并噁唑基)苯甲酸的氧化合成

采用气-液两相常压催化氧化法,以Co(AcO)2/Mn(AcO)2/NaBr为复合催化剂,合成了一种新型荧光增白剂中间体4-(2-苯并唑基)苯甲酸。考察了反应条件对收率的影响。实验结果表明,在催化剂质量分数1%、n(Co)∶n(Mn)=1∶3、溶剂质量分数80%、反应时间4 h、反应温度110℃、氧气速率15 mL.min-1条件下,单程收率达93%。脱水处理后反应液可循环使用5次,平均收率大于90%。

2-苯基苯并噁唑的合成

以邻氨基苯酚和苯甲酸为原料合成2–苯基苯并噁唑,用正交试验得出最佳合成条件:溴化四丁基铵(TBAB)为相转移催化剂,n(邻氨基苯酚):n(苯甲酸)=1:1.5,反应温度为110℃,反应时间为6h,产率89.5%。

2-(4’-羟基苯氧基)-6-氯苯并恶唑的合成新方法

以2,6-二氯苯并恶唑、对苯二酚为原料,于水—甲苯体系中在PTC的作用下合成2-(4’-羟基苯氧基)-6-氯苯并恶唑,彻底改变了原来的二甲苯单一溶剂反应体系,产品含量大于95%,收率达到83%以上。该方法克服了老工艺收率低,产量小,产品质量差的缺点。

微波促进下2-取代苯并噁唑类化合物合成研究

研究了离子液体介质中、微波辐射促进下邻氨基苯酚与醛的缩合反应,并利用该反应合成了一系列2-取代苯并噁唑.与文献方法相比,所报道的新方法具有反应速度快、收率高以及对环境友好等诸多优势,从而为2-取代苯并噁唑类化合物的合成提供了一条新途径.

Multifunctional 2-(2-hydroxyphenyl)benzoxazoles: Ready synthesis,mechanochromism, fluorescence imaging, and OLEDs

Triphenylamine(TPA)-containing 2-(2-hydroxyphenyl)benzoxazoles(2a-2c)have been synthesized via a highly efficient rhodium-catalyzed C–H/C–H cross-coupling reaction.Compound 2a is a novel mechanofluorochromic material with blue-shifted mechanochromic properties.Compounds 2b and 2c presented opposite mechanochromic trends.For 2b,the enol-form emission enhanced,and the ketoform emission blue-shift after grinding.In contrast,2c exhibited the weak enol-form emission disappeared and the keto-form emission slightly red-shift after grinding treatments.The estrone-containing2b-based water-dispersed nanoparticles(NPs)exhibit apparent dual-emission and were applied for fluorescence images.In addition,bis(TPA)-containing 2c-based devices exhibit dual-emission with good performance and a singlet exciton yield of 92%,which breaks through the theoretical upper limit of 25%in conventional fluorescent OLEDs.This is one of the highest exciton utilization values recorded for the ESIPT molecules with a dual emission system.

聚(2,5-苯并噁唑)/多壁碳纳米管复合材料的制备与性能

采用强氧化性酸处理多壁碳纳米管(MWNTs),形成功能化的多壁碳纳米管(MWNTs-COOH)。用傅里叶红外光谱(FT-IR)对处理前后MWNTs的表面官能团进行了分析,并利用原位聚合法成功制备了聚(2,5-苯并噁唑)(ABPBO)/MWNTs-COOH纳米复合材料。结果表明:碳纳米管经过酸处理后,表面含有较多羰基和羟基极性官能团,在ABPBO基体中分散均匀;复合材料保持了ABPBO的优异耐高温性能,其力学性能和光物理性能也得到了很大的提高。

苯并噁唑封端的聚(2,5-二丁氧基对苯乙炔)的合成

研究在2,5 二丁氧基对二氯苄的脱氯化氢聚合反应过程中,掺入2 (4 氯甲基苯基) 5 叔丁基苯并口恶唑,直接合成一种可溶性苯并口恶唑封端的聚(2,5 二丁氧基对苯乙炔)的方法;应用IR、1H NMR、UV Vis等分析方法,对其结构特征进行表征.分析结果表明:苯并口恶唑封端的聚(2,5 二丁氧基对苯乙炔)具有链状π 共轭体系的高分子结构特征.