Studies on the Catalysis by Lithium Perchlorate of Reactions of Aromatic Amines with Diethyl Azodicarboxylate and Naphtalen-2-ol with 4-phenyl-1,2,4-triazoline-3,5-dione

The ene-like reaction of naphtalen-1-ylamine and naphtalen-2-ylamine, and pyridin-2-ylamine with diethyl azodicarboxylate (DEAD) as well as that of naphthalen-2-ol with 4-phenyl-1,2,4-trizoline-3,5-dione is catalyzed by lithium perchlorate. Also conversion of ester function of (DEAD) to amide function in reaction with 2-aminopyridine and further rearrangement of ethyl N-pyridyn-2-ylcarbamoylazoformate into ethyl pyridin-2-ylcarbamate are catalyzed by LiClO₄.     

A comparison of the PVCILO calculated stabilization energies of the DA complexes of N-phenylmaleimide and 4-phenyl-1,2,4-triazoline-3,5-dione with methyl vinyl ether

Summary A PVCILO method has been used to compare the stabilization energies of the electron donor electron acceptor complexes between methyl vinyl ether as donor and the enophiles, 4-phenyl 1-1,2,4-triazoline-3,5-dione (1) and N-phenylmaleimide (2), respectively, as acceptor. A stabilization energry difference in favor of the more reactive 1 was obtained, which is being interpreted as an explanation for the enhanced rate of reaction of 1 vs 2, often by factors >10⁴.     

Step-Growth Polymerization of 4-(1-Naphthyl)-1,2,4-triazolidine-3,5-dione with Diisocyanates

Summary We have synthesized 4-(1-naphthyl)-1,2,4-triazolidine-3,5-dione (4-NTD) in high yield and purity from 1-naphthyl isocyanate and used it as a new monomer for polymer synthesis. A series of novel naphthalene-containing polyureas have been successfully prepared from 4-NTD with hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI) and toluene-2,4-diisocyanate (TDI) in N,N-dimethylacetamide (DMAc) or N-methylpyrrolidone (NMP) solution in the presence of pyridine, triethylamine or dibutyltin dilurate as catalysts. Some physical properties and structural characterization of these novel polyureas are reported. Fluorimetric studies of the new monomer, model compound as well as polymers were also investigated.     

Propellanes 93. Diels-Alder Reactions of Thioimido- and Lactamo-Propellanes with 4-Methyl-1,2,4-Triazoline-3,5-dione

A convenient method is described for the synthesis of γ-lactams from various imido-propellanes via the thio derivatives by desulfurization with tribulyltin hydride. Diels-Alder reactions between thioimido-, lactamo-, and imido-propellanes with methyl triazolinedione are compared.     

5,6-二溴苊-1,2-二酮的合成

以苊为原料,经N-溴代丁二酰亚胺溴化、三氧化铬氧化得5,6-二溴苊-1,2-二酮,2步反应的总收率为41.6%。目标化合物结构经ESI-MS、~1H NMR确证。     

2,2,6,6-四甲基-3,5-庚二酮的合成研究

以3,3-二甲基丁酮和2,2-二甲基丙酸甲酯为原料、氢化钠为强碱、四氢呋喃为反应溶剂,通过酮酯缩合反应合成了2,2,6,6-四甲基-3,5-庚二酮,考察了溶剂、反应时间、3,3-二甲基丁酮的滴加速度、酮酯摩尔比及氢化钠用量等因素对反应的影响.在3,3-二甲基丁酮、2,2-二甲基丙酸甲酯和氢化钠的摩尔比为1:1.5:3、4 h内滴加完3,3-二甲基丁酮溶液、回流反应8 h的最佳工艺条件下,产品收率可达64.5%.     

Synthesis of Photoactive Polyureas Derived from 4-(4-Dimethylaminophenyl)-1,2,4-triazolidine-3,5-dione and Diisocyanates

Summary 4-(4-Dimethylaminophenyl)-1,2,4-triazolidine-3,5-dione (DAPTD) was prepared from 4-dimethylaminobenzoic acid in five steps. The reaction of monomer DAPTD with n-isopropylisocyanate was performed at room temperature in N,N-dimethylacetamide (DMAc) solution and the resulting bis-urea derivative was obtained in high yield and was finally used as a model compound for polymerization reaction. The step-growth polymerization reactions of monomer with hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI) and toluene-2,4-diisocyanate (TDI) were performed in DMAc solution in the presence of pyridine, triethylamine or dibutyltin dilurate as catalysts. Some physical properties and structural characterization of these novel polyureas are reported. Fluorimetric studies of the model compound as well as polymers were performed.     

Identification of conjugated fatty acids by gas chromatography-mass spectrometry of 4-methyl-1,2,4-triazoline-3,5-dione adducts

4-Methyl-1,2,4-triazoline-3,5-dione was reacted with conjugated fatty acid methyl esters to form Diels-Alder cycloaddition products. The electron impact mass spectra of conjugated octadecadienoates and 9,11,13-octadecatrienoate were simple and informative and allowed the positions of the double bonds to be determined. The dienes gave single adducts whereas the triene formed four products that corresponded to two stereoisomers of the adducts of the 9,11-diene system and two of the 11,13-diene system. The method can be used to complement other methods for identifying conjugated fatty acids.     

Reaction of living polyTHF with amines: 4. Primary amines

Cationic living polyTHF reacts with primary amine rapidly under ambient conditions. When the amine is in excess the main product is a polymer possessing a terminal secondary amine ligand, and near quantitative conversion is achieved at ten fold excess. The proportion of mono- and disubstituted polymer formed at a given reagent ratio is insensitive to the nature of the amine. Surprisingly, therefore, it is found that the form of the un-neutralized amine product is dependent on the primary amine used, that from aniline exists as the free secondary amine whilst those from cyclohexylamine and n-butylamine exist as the acid salt. A hypothesis is put forward to explain these observations.     

Kinetics and modeling of 1-phenyl-1,2-propanedione hydrogenation

Kinetics and modeling of 1-phenyl-1,2-propanedione hydrogenation over cinchonidine-modified Pt/Al₂O₃ catalyst is reported. Hydrogenation experiments carried out in a pressurized autoclave (288 K, 1.2–6.5 bar hydrogen) revealed interesting kinetic effects which inspired the model development. The enantioselectivity towards the (R)-configuration, as well as the reaction rate and regioselectivity, depended on the modifier concentration having a maximum. The enantio- and regioselective effects were explained by the kinetic model, which assumes different number of sites for adsorption of the carbonyl groups of the 1-phenyl-1,2-propanedione as well as for the cinchonidine adsorbed in flat and tilted modes. The number of adsorption sites needed for the different species were obtained from molecular considerations and the hydrogenation rate constants were determined along with the adsorption parameters by non-linear regression analysis. A comparison of model predictions with experimental data revealed that the model accounts for the kinetic regularities.     

SiO2负载磷钨酸铯盐催化剂上香兰素与1，2-丙二醇的缩合反应

制备一系列硅胶(SiO2)负载的磷钨酸铯盐催化剂,将其用于香兰素与1,2-丙二醇的缩合反应,合成香兰素丙二醇缩醛,考察催化剂中Cs+取代数、磷钨酸铯盐负载量、催化剂用量、1,2-丙二醇与香兰素摩尔比及反应时间对缩合反应的影响.结果表明:磷钨酸铯盐的Cs+取代数为2.5、负载量为40%时催化剂活性最高;在反应温度368 K、n(1,2-丙二醇)/n(香兰素)=2.4、催化剂用量占反应体系质量分数1.5%、带水剂苯的用量30 mL、回流反应3 h的条件下,香兰素的转化率达到86.6%,香兰素丙二醇缩醛的选择性为100%.     

Cationic ring-opening polymerization of 2-phenyl-1,2-oxaphospholane (deoxophostone)

Summary The ring-opening polymerization of deoxophostone 5, a five-membered cyclic phosphinite, has been studied. Some cationic initiators gave polymer whereas anionic and radical initiators as well as metal chloride (Lewis acid) catalysts did not yield polymer. The polymer consisted of a phosphine oxide repeating unit 6. The polymerization proceeded via the Arbuzov-type reaction. The reduction of polymer 6 with a HSiCl₃/Et₃N system gave polyphosphine 7.     

Phase transfer catalyzed polymerization of 4-hydroxy-3,5-dimethylbenzyl alcohol and copolymerization of 4-bromo-2,6-dimethylphenol with 4-hydroxy-3,5-dimethylbenzyl alcohol

Summary This paper describes the phase transfer catalyzed (PTC) polymerization of 4-hydroxy-3,5-dimethylbenzyl alcohol (1) and the PTC polymerization of 4-bromo-2,6-dimethylphenol (19) in the presence of 4-hydroxy-3,5-dimethylbenzyl alcohol (1). At 89% conversion the homopolymerization of 1 produced a 95% yield of 4,4-dihydroxy-3,3,5,5-tetramethyldiphenylmethane (3) and a 5% yield of oligomers. The polymerization of 19 in the presence of 1 resulted in poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) polymers in 71 to 89% yields. The 200 MHz ¹H-NMR spectroscopy analyses of the resulting PPO polymers indicate that they represent a mixture of bifunctional (PPO-2OH) and monofunctional (PPO-OH) polymers. A radicalanion mechanism was proposed to account for both the homopolymerization and the copolymerization reactions.     

Simple synthesis of polymeric primary aromatic amines

Summary A new simple and versatile method of obtaining polymers bearing aromatic primary amino groups was developed. The method consists in the reaction of an alkylating polymer with sodium 4-acetylaminobenzenesulfinate and subsequent deacetylation of the intermediate polymer by acid hydrolysis. Alkylating polymers such as chloromethylated polystyrene resin, tosylated macroporous poly (2-hydroxyethyl methacrylate), macroporous poly(glycidyl methacrylate) and PVC were used in the alkylation performed either in an organic swelling solvent or in an aqueous suspension under phase transfer catalysis conditions. Yields in the alkylation step depend largely on the type of the alkylating group, hydrolysis yields are essentially quantitative.     

邻苯二胺与醛缩合反应的研究

邻苯二胺与二分子醛缩合形成分子内双席佛碱,接着发生分子内熏排形成1-取代-2-芳基苯并咪唑衍生物。实验结果表明,与醛基相连的基团的给电子能力种类决定了分子内重排反应产物-1-取代-2-芳基苯并咪礁衍生物的结构。文章为一步法合成1-取代-2-芳基苯并眯唑衍生物提供了参考依据。     

Selective and facile oxidative desulfurization of thioureas and thiobarbituric acids with singlet molecular oxygen generated from trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane

An efficient and facile procedure using trans-3,5-dihydroperoxy-3,5-dimethyl-1,2-dioxolane has been developed for oxidative desulfurization of thioureas and thiobarbituric acids. The reactions proceeded smoothly very fast under mild conditions in basic media at room temperature to afford the respective ureas in excellent yields. Simple procedure and work up, mild conditions, high yields, short reaction times, use of highly potent and non-toxic oxidant are the main merits of the present method.     

辛酰溴苯腈的合成研究

介绍了辛酰溴苯腈的性质、用途并研究了以对羟基苯甲腈为起始原料,经溴化,酰基化合成辛酰溴苯腈原药的工艺路线,总收率达85%,原药含量达到97%。     

Reaction of 3H, 6H-1, 2-Dithiolo[4,3-c]1,2-dithiole-3, 6-dithione with primary aliphatic amines

The reaction of 3H,6H-1,2-dithiolo[4,3-c]1,2-dithiole-3, 6-dithione ( 1 ) with primary aliphatic amines ( 8a , b ) gives 3H,6H-3,6-bisalkylimino-1,2-dithiolo[4,3-c]1,2- dithiole ( 9a , b ), 3H,3-N-alkylamino-5-N-alkylthiocarbamido-1, 2-dithiolium-4-thiolate ( 10a , b ) and 3H,3-N-alkylimino-4-alkylamino-5-N-alkylthiocarbamido-1,2-dithiole ( 11a , b ). The compounds 9-11 can be formed from one another. The compounds 10a , b react with nickel chloride to the stable complexes 14a , b . In basic medium 10 gives the salt of 3H,3N-alkylthiocarbamido-1,2-dithiole-4-thiolate 15 , which reacts with methyl iodide to 3H,3N-alkylimino-5-N-alkylthiocarbamido-4-methylthio-1,2-dithiole 16 .