SYNTHESIS AND PROPERTIES OF POLY-1,3,5-TRIAZINES

Two new polytriazines: poly[2-methyl-4, 6-(4,′4″-diphenylene)-1, 3, 5-triazine] (Ⅰ) and poly[2-phenyl-4, 6-(4′, 4″-diphenylene)-1, 3, 5-triazine] (Ⅱ) were synthesized from the solution condensation of biphenyl-4, 4′-diamidine dihydrochloride with acetic anhydride and biphenyl-4, 4′-diamidine with benzaldehyde respectively. These two polymers were characterized by TGA, DTA, elemental analysis and IR spectroscopy. They exhibited good thermal oxidative stability as shown by the fact that the powders of these polymers suffered 5.4%, 2.4% weight loss after isothermal aging in air at 300℃for 200 hours. The decomposition temperature of (Ⅱ) was 583℃in air and 590℃in N_2. These linear poly-1, 3, 5-triazines were soluble in concentrated sulfuric acid, phosphoric acid and trifluoroacetic acid whereas the erosslinked poly-1, 3, 5-triazines reported in the literature were insoluble and infusible.It is interesting that these polymers can form complexes with metal halides as determined by X-ray photoelectron spectroscopy (XPS). The polymer metal complex (Ⅲ). PdCl_2 possesses catalytic activity for hydrogenation.     

Synthesis and Reactions of Trifluoromethyl-Substituted 1,3,5-Triazines

A variety of di- and trifluoromethyl-s-triazines are prepared following straightforward synthetic protocols from simple, commercially available starting materials. Trichloromethyl-substituted triazine electrophiles are obtained in good yield and react with amine nucleophiles to afford aminotriazine products in good to excellent yield. The nucleophilic aromatic substitution reaction is broad in scope and proceeds smoothly with both aromatic and aliphatic (primary, secondary, and branched) amines in the presence of non-participating functional groups including alcohols, carboxylic acids, indoles, and common amine protecting groups. Furthermore, most reactions require only a catalytic amount of 4-DMAP with no stoichiometric base and are complete within two hours at ambient temperature.     

Annelation of the thiazole ring to 1,2,4-triazines by tandem AN—AN or SN H—SN H reactions

The reactions of 3-aryl-1,2,4-triazines with aromatic thioamides and 4-arylthiosemicarbazides in acetic anhydride at room temperature afforded cyclic products of the tandem nucleophilic addition reactions, viz., tetrahydrothiazolo[4,5-e]-annelated 1,2,4-triazines, in good yields. The latter underwent aromatization in the presence of potassium permanganate.     

Lanthanide(III) ion catalyzed reaction of ammonia and nitriles: Synthesis of 2,4,6-trisubstituted-s-triazines

Lanthanum and yttrium trifluoromethanesulfonates at 1 mole % concentration, have been found to catalyze a reaction between ammonia and aromatic nitriles to yield symmetrically substituted 2,4,6-triaryl-s-triazines. The generally high yields and relatively mild reaction conditions of this procedure suggest it as an alternative to other aromatic nitrile cyclotrimerization reactions. Of the aliphatic nitriles studied, acetonitrile and cyclopropanecarbonitrile gave good yields of triazine, propionitrile and butyronitrile gave significantly reduced yields of triazines 3b and 3c respectively. Rearrangement of 3a and 3b to alkylated-4-aminopyrimidines was observed.     

Synthesis and structure of new 1,3,5-triazine-pyrazole derivatives

We have studied the reaction of methylenedicarbonyl compounds with 4,6-disubstituted 2-hydrazinyl-1,3,5-triazine in order to obtain novel coupled biheterocyclic aromatic systems with potential bioactivity. Reaction conditions were studied and optimized, and a series of 4,6-disubstituted 2-(1H-pyrazolyl)-1,3,5-triazines were obtained with good yield.     

An efficient entry to furo[2,3-d]pyrimidines via inverse electron demand Diels–Alder reactions of 2-aminofurans with 1,3,5-triazines

Furo[2,3-d]pyrimidines were readily prepared via an inverse electron demand Diels–Alder (IDA) reaction between 2-aminofurans and 1,3,5-triazines. 2-Aminofurans proved to be productive dienophiles leading to the IDA product in moderate to good yields. This study further expanded the scope of 1,3,5-triazine IDA reactions with five-membered aromatic heterocycles as dienophiles.     

Relation of the chemical structure of polycyanurates to thermal and mechanical properties

Forty polycyanurates were prepared by the interfacial polycondensation of 2-substituted 4,6-dichloro-s-triazines with various aromatic diols. Nitrobenzene was used as a solvent, aqueous sodium hydroxide as an acid acceptor, and a cationic emulsifier as an accelerator. The rate of reaction was largely increased by ultrasonic irradiation. The polymer yield was in the range 57–91%, and the reduced viscosity was 0.41–3.5. The polymers were soluble in chloroform, nitrobenzene, and o-dichlorobenzene but insoluble in common organic solvents such as alcohol, acetone, and hydrocarbons. A clear film was obtained from the chloroform-soluble polymers after evaporation of the solvent. The softening temperature and the thermal stability of each polycyanurate was significantly related to the substituent on the s-triazine nucleus as well as to the diol component in the molecular chain. Polymers of favorable properties were derived from 2-substituted 4,6-dichloro-s-triazines with R = ? C₆H₅, ? N(C₆H₅)₂, ? N(C₆H₁₁)₂, ? N(C₆H₅)(SO₂C₆H₄CH₃), or carbazyl and aromatic diols such as 4,4′-dihydroxybenzophenone, Bisphenol A, or phenolphthalein. These polymers showed tensile strength of 500–670 kg/cm², elongation at break of 2.9–6.0%, and a minor weight loss at 300–350°C.     

Die Synthese von asymmetrisch substituierten o-Hydroxyphenyl-s-triazinen

Mono- and bis-(2-hydroxyphenyl)-s-triazines 4 , 14 , 18 , 22 , 28 , 29 can be prepared by (a) reaction of salicylic acid esters 2 with amidines 3 ; (b) reaction of 4H-1, 3-benzoxazin-4-ones 10 with amidines 3 ; and (c) Friedel-Crafts-reaction of chloro-s-triazines 26 , 27 with resorcinol 24 . In case (b) the path of reaction is determined by the character of substituent R⁴ in 10 . Scope and limitations of these reactions and accessibility of starting materials are discussed.     

Synthesis of Aromatic Polythioethers Containing 1,3,5-Triazine Ring by Aromatic Nucleophilic Substitution Polymerization

Abstract

Reaction of 2,4-dichloro-6-phenyl-1,3,5-triazines with bis(4-mercaptophenyl) sulfide in the presence of a base in THF afforded the corresponding condensation polymer as a whole aromatic polythioether in moderate yield. The polymerization of several 2,4-dichloro-1,3,5-triazine derivatives with this dithiols also proceeded in the o-dichlorobenzene-water two-phase system by using phase transfer catalysts. The resulting polymers consisted of THF-soluble and -insoluble fractions. The x-ray diffraction pattern indicated that these THF-insoluble polymers have a highly crystalline nature. Further, the polymers obtained here showed high thermal stability.     

聚-1,3,5-三嗪的合成及性能

将联苯二脒与苯甲醛或其盐酸盐与乙酸酐进行缩聚反应,合成了两种新的聚-1,3,5-三嗪,用元素分析、红外光谱、差热分析及热重分析进行了表征,聚合物的η_(比粘)为0.46—0.56分升/克(1％硫酸,25℃),具有良好的耐温性和耐水解性,也有一定的溶解性,利用这种聚-1,3,5-三嗪和二氯化钯反应,可以制成新的高分子络合物。     

Soluble aromatic polyamides modified by incorporation of 1,2,4-triazole and pentadecyl units into the backbone of polymer

Abstract

A new series of soluble aromatic polyamides was synthesized by low temperature solution polycondensation of novel aromatic diamine namely 3,5-bis-(4′-amino phenyl)-4-(4″-methoxy-2″-pentadecyl phenyl) 1,2,4-triazole (VII) with aromatic diacid chlorides, viz. isophthaloyl chloride (IPC) and terephthaloyl chloride (TPC). The aromaticdiamine (VII) was characterized by elemental analysis, FT-IR, NMR (¹H, ¹³C), and mass spectrometry. Copolyamides were also synthesized by employing various mole proportions of IPC and TPC with diamine (VII). Inherent viscosities of these polyamides were in the range of 0.50–0.65 dL/g in DMAc, indicating formation of moderate to high molecular weight of polyamides. These polyamides showed good solubility in polar aprotic solvents such as N,N-Dimethyl acetamide (DMAc), N-Methyl 2-pyrrolidone (NMP), N, N, Dimethyl formamide (DMF), and Dimethyl sulphoxide (DMSO), which may be due to incorporation of pendant methoxyphenyl moiety with pentadecyl units. The amorphous morphology of polyamides as evidenced by XRD. These polyamides had lower glass transition temperatures; as determined by DSC, compared to the T_g of conventional aromatic polyamides due to internal plasticization effect of long alkyl pentadecyl group. Polymers showed good thermal stability, with initial decomposition temperature above 300?°C.     

Reactions of azinium cations. 8. Electron structures of 3-substituted 1,2,4-triazines and protonation,quaternization, and reactions with nucleophiles

The electron structures of 3-substituted 1,2,4-triazines and isomeric N-methyltriazinium salts were calculated by the CNDO/2 method. The results of the calculations were compared with the parameters of the ¹³C, ¹⁵N, and ¹⁴N NMR spectra, as well as with experimental data on the protonation, N-alkylation, and reactions of 1,2,4-triazines with simple nucleophiles. The protonation centers of 1,2,4-triazines were determined by means of ¹H, ¹³C, and ¹⁴N NMR spectroscopy. The covalent adducts formed by the proton salts of 3-methoxy-, 3-methylthio-, 3-morpholino-, and 3-pyrrolidino-1,2,4-triazine with water and methanol were recorded by ¹H NMR spectroscopy.Communication 7: O. N. Chupakhin, V. N. Chaurushin, I. V. Kazantseva, M. G. Poinzovskii, E. O. Sidorov, P. A. Torgashev, and A. V. Belik, Khim. Geterotsikl. Soedin., No. 10, 1385 (1987).Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 525–533, April, 1988.     

Synthesis of substituted 2-amino-4,6-bis(nonafluoro-tert-butyl)-1,3,5-triazines

A procedure was developed for the synthesis of substituted 2-amino-4,6-bis(nonafluoro-tert-butyl)-1,3,5-triazines from 2-chloro-4,6-bis(nonafluoro-tert-butyl)-1,3,5-triazine and aliphatic and aromatic amines. The data of¹⁹F NMR spectroscopy are indicative of the presence of a barrier to internal rotation. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1568–1572, August, 1999.     

Stable σH-adducts in reactions of ferrocenyllithium with azines

Stable σ^H-adducts as intermediates of the nucleophilic substitution of hydrogen in 3-(2-pyridyl)-1,2,4-triazines were obtained for the first time using ferrocenyllithium as a nucleophilic reagent. The three-dimensional structures of the reaction products were established based on the X-ray diffraction study of 1-[4-ethyl-6-phenyl-3-(2-pyridyl)-5(H)-1,2,4-triazin-5-yl]ferrocene.     

含苯并呋喃、苯并噻吩环的聚苯基-1,2,4-三嗪

本文首次合成了几种含苯并呋喃苯并噻吩环的新的芳香族四羰基化合物,并对它们进行了元素分析和红外光谱测定。将所合成的芳族四羰基化合物分别与芳族双酰胺腙反应,得到了一系列含氧、硫杂原子的新的聚苯基-1,2,4-三嗪。这些高聚物均可以浇铸成膜。对聚合物所进行的一般性能测试的结果表明,它们具有良好的力学性能和较好的耐温性。     

Synthesis and molecular structure of 2-methoxy-4-amino-6-dinitromethyl-1,3,5-triazines zwitterionic salts

Zwitterionic salts of 2-methoxy-4-amino-6-dinitromethyl-1,3,5-triazines were synthesized. The structure of the compounds and the site of nitrogen protonation in the 1,3,5-triazine ring were established based on IR and ¹H NMR spectra and on the data of X-ray diffraction analysis.     

Fluorene-bridged polyphenylquinoxalines with high solubility and good thermal stability: Synthesis and properties

<正>A novel fluorene-bridged tetraketone monomer,9,9-bis[(4-benzilyloxy)phenyl]fluorene(FLTK) was synthesized and characterized.The tetraketone was polymerized with various aromatic tetraamines to afford a series of polyphenylquinoxalines(PPQs).The obtained polymers were found to be soluble in common organic solvents such as N-methyl-2-pyrrolidone(NMP),chloroform and m-cresol.Flexible and tough PPQ films obtained by spin-casting their NMP solutions exhibited tensile strengths higher than 60 MPa.The films also demonstrated good thermal stability up to 500℃in nitrogen and glass transition temperatures higher than 280℃.In addition,the PPQ films exhibited good hydrolytic stability. High surface and volume resistivity retentions were achieved for the films after immersion or boiling in water for 24 h.     

Synthesis of 4-(2-acetoxyethoxymethyl)-6-methyl-1,2,4-triazin-3(4H)-one 1-oxide as thymidine analogue

Alkylation of the sodium salt and the trimethyl silylated derivatives of 6-methyl-1,2,4-triazin-3(4H)-one 1-oxide with chloromethoxyethyl acetate, n-hexyl chloride and benzyl bromide gave the 4-substituted products. However, attempts to achieve the ring closure of N⁴-(2-acetoxyethoxymethyl)thiosemicarbazide with bicarbonyl compounds to the corresponding as-triazines under different reaction conditions was not possible without disruption of the acetoxyethoxymethyl moiety. Although the as-triazine nucleoside analog II did not show antileukemic activity, this and other 4-alkylated as-triazine 1-oxides revealed good growth inhibitory effects against a representative spectrum of microorganisms.     

Condensed Tetrazolo-1,3,5-triazines. 1. Synthesis of 5-Polynitromethyltetrazolo[1,5-<Emphasis Type="Italic">a</Emphasis>]-1,3,5-triazin-7-one Salts

The aziridation of 2-R-4,6-bis(trinitromethyl)-1,3,5-triazines containing electron-donor substituents has been studied. It was found that the corresponding 4-azido-2-dialkylamino-6-trinitromethyl-1,3,5-triazines are formed when R = NMe₂, NEt₂. When R = O^–NMe₄ ⁺ a novel reaction route was discovered leading to the tetramethylammonium salt of 5-polynitromethyltetrazolo[1,5-a]-1,3,5-triazin-7-one which is formed as a result of azido-tetrazole and lactim-lactam tautomeric conversion. Denitration of this salt at the trinitromethyl group occurs with retention of the tetrazolo-1,3,5-triazine structure. An X-ray analysis was carried out for the denitration product which was the dipotassium salt of 5-dinitromethyltetrazolo[1,5-a]-1,3,5-triazin-7-one.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 259–266, February, 2005.     

Polybenzimidazoles tethered with N‐phenyl 1,2,4‐triazole units as polymer electrolytes for fuel cells

Polybenzimidazole (PBI) polymers tethered with N‐phenyl 1,2,4‐triazole (NPT) groups were prepared from a newly synthesized aromatic diacid, 3′‐(4‐phenyl‐4H‐1,2,4‐triazole‐3,5‐diyl) dibenzoic acid (PTDBA). The obtained polymers show superior thermal and chemical stability and good solubility in many aprotic solvents. The inherent viscosities of all polymers were around 1 dL/g. They exhibit high thermal stability with initial decomposition temperature ranging from 515 to 530 °C, high glass transition temperature ranging from 375 to 410 °C, and good mechanical properties with tensile stress in the range of 66–98 MPa and modulus 1897–2600 MPa. XRD analysis indicates that these polymers are amorphous in nature. Physicochemical properties such as water and phosphoric acid‐uptake, oxidative stability, and proton conductivity of membranes of these polymers have also been determined. The proton conductivity ranged from 4.7 × 10^?3 to 1.8 × 10^?2 S cm^?1 at 175 °C in dry conditions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2289–2303, 2009