3,5-二氯-2,4,6-三硝基苯胺及其衍生物的合成

分别以3,5-二氯苯胺为原料,经N保护、硝化、水解以及以1,3,5-三氯-2,4,6-三硝基苯(TCTNB)为原料,经叔丁胺化,再在三氟乙酸中脱叔丁基2种方法合成了3,5-二氯-2,4,6-三硝基苯胺。 与甲胺反应,合成了3,5-二甲氨基-2,4,6-三硝基苯胺,收率85%,再用混酸硝化合成了3,5-二甲硝胺基-2,4,6-三硝基苯胺的硝酸盐,收率70%。 采用核磁共振、质谱、红外和元素分析等进行了结构表征。 探讨了不同参数下TCTNB的氨化结果。 优化的条件为：n(TCTNB)∶n(叔丁胺)=1∶2,CuO为催化剂,KHCO3为碱。     

核黄素荧光猝灭法测定2,4,6-三硝基苯酚

基于核黄素与2,4,6-三硝基苯酚混合后产生荧光猝灭现象,建立了核黄素作为荧光探针测定2,4,6-三硝基苯酚的新方法。 在0.2 mol/L磷酸盐(NaH₂PO₄-Na₂HPO₄)缓冲溶液(pH=6.2)中,响应时间为1 min时,检测2,4,6-三硝基苯酚的线性范围为2.5~1000 μmol/L,相关系数为0.9938,检测限为0.55 μmol/L。 当加入5.00和20.00 μmol/L 2,4,6-三硝基苯酚到水样后,回收率在98.2%~103.5%之间。 方法简便,选择性好,线性范围宽,可用于实际水样中2,4,6-三硝基苯酚的定性定量分析。     

N-硝基-2,4,6-三硝基苯基脲的合成及生物活性研究

在甲苯溶液中，将N-硝基-2,4,6-三硝基苯胺与固体光气反应, 得到酰氯中间体, 该中间体无需分离, 然后直接与其它取代苯胺反应合成了13个未见文献报道的N-硝基-2,4,6-三硝基苯基脲类化合物, 其结构经¹H NMR, IR, MS和元素分析确证. 初步测试结果表明: 当浓度为500 mg/L时, 部分化合物具有较好的抑制稗草生长活性.     

1,1-二(2,4,6-三硝基苯甲酰胺基)-2,2-硝基乙烯的合成

以1,1-二氨基-2,2-二硝基乙烯(FOX-7)和2,4,6-三硝基苯甲酰氯(TNBC)为原料反应合成得到了1,1-二(2,4,6-三硝基苯甲酰胺基)-2,2-二硝基乙烯,并通过单因素试验和正交试验方法,分别探讨了反应介质、缚酸剂、反应温度和反应时间等对产物产率的影响,得到适宜的工艺条件为:FOX-7与TNBC物质的量的比1∶2.4,以四氢呋喃(THF)为反应介质,N,N-二甲基甲酰胺(DMF)为缚酸剂,反应温度0℃,反应时间48 h,产率可达94％.采用紫外可见光谱(UV-Vis)、核磁共振氢谱(1H NMR)、核磁共振碳谱(13C NMR)、红外光谱(FT-IR)、质谱(MS)及元素分析等对产物的结构进行了表征.利用差热分析仪对产物热稳定性进行了研究,结果表明,产物在空气中分解峰值温度为167℃,理论计算爆速为7.434km· s-1,爆压为23.67 GPa.     

2,4,6-三甲基苯甲醛的合成

以1,3,5-三甲苯为原料,用硝酸和醋酸的混酸在5℃下乙酸酐溶液中对其硝化生成2,4,6-三甲基硝基苯(1),收率为90．6％。化合物1由铁粉和盐酸在水、乙醇混合溶剂中进行还原得到2,4,6-三甲基苯胺(2),收率为80．27％。将化合物2制备为盐酸重氮盐(3)后滴加到新制的甲醛肟中反应,浓缩得到2,4,6-三甲基苯甲醛(4),收率为52％。目标化合物结构经质谱、核磁氢谱确证,总收率37．82％,纯度98％。     

2,4,6-三硝基-2,4,6-三氮杂环己酮的晶体形貌预测

利用Materials Studio 5.0软件包中的Morphology模块所含的BFDH、Growth Morphology和Equilibri-um Morphology三种方法计算了2,4,6-三硝基-2,4,6-三氮杂环己酮的晶体形貌,得到了特定晶面的面积、附着能、表面能及晶面相对生长速率等参数,确定了形态学上重要的生长晶面.各晶面的表面结构分析结果表明,(101)和(111)晶面为强极性晶面,(002)、(110)和(021)晶面为极性晶面,而(020)晶面为非极性晶面.据此可以预测,在强极性的质子溶剂中,(101)和(111)晶面为形态学上重要的晶面,(002)、(110)和(021)晶面的显露面可能增加,而(020)晶面会变小或消失.在非极性溶剂中,情况则可能刚好相反.     

一锅法合成二硝基五亚甲基四胺反应机理的研究

二硝基五亚甲基四胺(DPT)是高性能单质炸药奥克托金(HMX)的重要硝化前体.以尿素为起始原料,中间产物不分离,经硝化、水解、Mannich缩合等反应得到DPT,总收率63.2%.通过分离、捕获中间体以及同位素示踪实验研究了一锅法合成DPT的反应机理.分离出了稳定的中间体二硝基脲、硝酰胺和二羟甲基硝酰胺,用苯磺酰氯捕获到了活性中间体1-硝基-六氢均三嗪.以氘代甲醛、二羟甲基硝酰胺和氨缩合得到氘标记的DPT,1HNMR和MS分析结果表明:在反应过程中二羟甲基硝酰胺解离释放出甲醛和硝酰胺,小分子碎片随机组合生成了三嗪化合物,进而生成DPT.     

2,4,6-三硝基-1,3,5-三羟基苯的一种新制备方法

为降低2,4,6-三硝基-1,3,5-三羟基苯（TNPG）在生产过程中对环境造成的危害并探究其高效且低污染的规模化生产工艺，本文以3,5-二甲氧基氟苯为原料，通过硝酸钾-浓硫酸组成的硝化体系进行硝化。在冰水淬灭硝化反应时氟原子被水解，得到中间体3,5-二甲氧基-2,4,6-三硝基苯酚（2），用冰乙酸溶解中间体2，再用氢溴酸脱甲基得到目标化合物TNPG，总收率96.13%。对该反应进行公斤级规模放大，发现重现性较好。采用核磁共振（NMR）、X-射线单晶衍射分析（XRD）和元素分析（EA）等方法对TNPG进行结构表征；利用差示扫描量热（DSC）和热重（TG）方法研究TNPG的热分解过程，结果发现：TNPG在157.11 ℃出现吸热峰，在171.60 ℃和191.63 ℃处出现放热峰。该合成方法简洁且收率较高。在温度为-173.15 ℃时，6TNPG·4H2O单晶密度为1.939 g/cm³，属trigonal晶系，P-3c1空间群。     

制备2,4,6-三甲基苯甲醛的新方法

1,3,5-三甲苯与溴素在水溶液中反应生成2,4,6-三甲基溴苯(1,收率90%);1制备成格氏试剂再与甲醛反应得到2,4,6-三甲基苄醇(2,收率79%)。2经铬酸氧化得2,4,6-三甲基苯甲醛(3,收率90.3%)。3的总收率达64.2%,纯度97%。2和3的结构经1H NMR和MS确证。     

5-(N-2-羟乙基)羟乙酰氨基-N,N′-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺的合成

5-氨基-N,N′-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺(2)在N,N-二甲基乙酰胺中可直接与乙酰氧基乙酰氯反应,产物再经碱性水解得5-羟乙酰氨基-N,N′-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺(3),后者再与氯乙醇反应生成5-(N-2-羟乙基)羟乙酰胺基-N,N′-双(2,3-二羟丙基)-2,4,6-三碘-1,3-苯二甲酰胺(1),经乙二醇甲醚/正丁醇重结晶,纯度高于99%(HPLC),反应总收率由39.3%(文献值)提高到55.1%.     

2,4,6-trichloropyrimidine. Reaction with ethanolamine and diethanolamine

2,4,6-Trichloropyrimidine, 1, reacts with neutral nucleophiles, such as ethanolamine and diethanolamine, to produce both mono- and disubstituted derivatives resulting from replacement of either one (2 and 3) or two (4) chlorine atoms. The third chlorine could not be replaced by these nucleophiles. Failure of this final step was attributed to intramolecular hydrogen bonding of the nucleophiles.     

Synthesis and structure of tetra- and triphenylantimony 2,4,6-trichlorophenoxides

The reaction of pentaphenylantimony with 2,4,6-trichlorophenol or bis(2,4,6-trichlorophenoxy)- triphenylantimony in toluene afforded (2,4,6-trichlorophenoxy)tetraphenylantimony. The reaction of triphenylantimony with tert-butyl hydroperoxide and 2,4,6-trichlorophenol led to the formation of bis(2,4,6-trichlorophenoxy) triphenylantimony; further reaction of the latter with triphenylantimony dichloride provided (2,4,6-trichlorophenoxy)triphenylantimony chloride. According to the XRD data, the antimony atoms in the prepared compounds had distorted trigonal-bipyramidal coordination with electronegative ligands in axial positions.     

THE REACTION OF DIMETHYL SULFOXIDE AND SYM-DICHLORO-BIS(2,4,6-TRICHLOROPHENYL) UREA

Abstract

Sym-dichloro-bis(2,4,6-trichlorophenyl) urea reacts explosively with dimethyl sulfoxide to yield phosgene, formaldehyde, methane, sulfur dioxide, ethylene chloride, methylene dichloride, chlorinated disulfides, and insoluble bis(2,4,6-trichlorophenyl) urea. The products, other than bis(2,4,6-trichlorophenyl) urea, are separated and characterized by means of gas chromatography and mass spectrometry. A homolytic mechanism is proposed for the reaction.     

Reaction of 2,4,6-substituted pyrylium salts with compounds containing a C = N bond

2,4,6-Substituted pyrylium salts add azomethines to give pyridinium salts and aromatic aldehydes. The latter can be condensed with the methyl groups of the pyridinium salts. Benzaldoxime, benzalazine, benzalphenylhydrazine, urea, thiourea, and phenyl isothiocyanate react with 2,4,6-triphenylpyrylium perchlorate similarly to give, respectively, 2,4,6-triphenylpyridine N-oxide, 2,4,6-triphenylpyridine, or N-substituted 2,4,6-triphenylpyridinium perchlorates.     

Influence of fluorophor dye labels on the migration behavior of polymerase chain reaction--amplified short tandem repeats during denaturing capillary electrophoresis.

The determination of the length of polymerase chain reaction (PCR)-amplified short tandem repeats (STRs) by denaturing capillary electrophoresis (CE) is a standard procedure for purposes of genotyping. We show that dye-specific mobility anomalies exist for 5'-fluorophor-labelled single-stranded DNA (ssDNA) fragments in CE using the performance-optimized polymer 4 (POP4) buffer sieving matrix, containing the entangled poly(N,N-dimethylacrylamide) polymer, urea, and 2-pyrrolidinone. The dye-specific retardation effects relative to coseparated GeneScan-500 [TAMRA] standard fragments can lead to wrong genotyping, even for allele-specific fragments of pentanucleotide STRs, when comparing the relative calculated sizes of identical fragments, labelled with rhodamine (ROX, TAMRA) or fluorescein dyes (FAM, 6-FAM, HEX, JOE, NED, TET): The size of fluorescein dye-labelled fragments of appr. 100 b in length appears to be smaller by up to 6.5 b. This effect becomes more dramatic with decreasing size: a 6-FAM-labelled 24-mer oligonucleotide appeared to be smaller by 11 b. In contrast, in classical urea/polyacrylamide slab-gel electrophoresis only a small dye-specific retardation of identical fragments is observed. The dye-specific effects are superimposed by weaker size and sequence-dependent anomalies of fragment mobility. Therefore, in denaturing CE the coseparation of a defined allele ladder labelled with the same dye as the unknown sample fragments remains the method of choice for accurate genotyping.     

The thermal decomposition of sym-dichlorobis (2,4,6-trichlorophenyl) urea in KBr

Infrared spectra of sym-dichlorobis (2,4,6-trichlorophenyl) urea over the range 4000–250 cm⁻¹ have been obtained on samples prepared in KBr discs and stored for several hours at elevated temperatures. The subject compound undergoes thermal decomposition by cleavage of the N---Cl bond and the formation of sym-2,4,6-trichlorophenyl urea with some aromatic halogenation of 2,4-dichlorophenyl groups present in the sample.     

Synthesis and Structure of E-2-(2,4,6-tri tert butylphenylphosphinyl)-2-〔N-(tert-butyldimethylsilyl)-N-(p-chrolophenyl)〕amino-1-(2,4,6-tri tert-butyl-phenyl)phosphacthylene

1　INTRODUCTIONItwaswellknown thatelementsofthesecondary and higherrow are in generaldifficulty to form multiplebondsin which apπ hybridized stateisinvolved〔1〕.Thus,simple compounds containing multiple phosphorus carbon bonds,such as methyl dynephosphine( HC≡P) 〔2 - 3〕 and methylenephosphine( H2 C=PH〔4〕,are notstableat room temperature.Three methods to stabilize compounds containing double ormultiple bond involving phosphorusatom in the pπ hybridized state are often used.The f…     

Cocondensation of urea with methylolphenols in acidic conditions

The reactions of urea with methylolphenols under acidic conditions were investigated using 2- and 4-hydroxybenzyl alcohol and crude 2,4,6-trimethylophenol as model compounds. The reaction products were analyzed with ¹³C-NMR spectroscopy and GPC. From the reaction of urea with 4-hydroxybenzyl alcohol, the formations of 4-hydroxybenzylurea, N,N′-bis (4-hydroxybenzyl) urea, and tris(4-hydroxybenzyl) urea were confirmed and the formations of N,N-bis(4-hydroxybenzyl) urea and tetrakis (4-hydroxybenzyl) urea were suggested. From the reaction of urea and 2-hydroxybenzyl alcohol, 2-hydroxybenzylurea and N,N′-bis(2-hydroxybenzyl) urea were identified. Further, the alternative copolymer of urea and phenol could be synthesized by the reaction of urea with 2,4,6-trimethylophenol. It was also found that the cocondensation between p-methylol group and urea prevails against the self-condensation of the methylolphenol even at the low pH below 3.0, and that p-methylol group has the stronger reactivity to urea than o-methylol group. © 1992 John Wiley & Sons, Inc.     

Theoretical calculation of nitro-1-(2,4,6-trinitrophenyl)-1H-azoles energetic compounds

In order to study the properties of new energetic compounds formed by introducing nitroazoles into 2,4,6-trinitrobezene, the density, heat of formation and detonation properties of 36 nitro-1-(2,4,6-trinitrobenzene)-1H-azoles energetic compounds are studied by density functional theory, and their stability and melting point are predicted. The results show that most of target compounds have good detonation properties and stability. And it is found that nitro-1-(2,4,6-Trinitrophenyl)-1H-pyrrole compounds and nitro-1-(2,4,6-trinitrop-enyl)-1H-Imidazole compounds have good thermal stability, and their weakest bond is C NO₂ bond, the bond dissociation energy of the weakest bond is 222–238 kJ mol⁻¹ and close to 2,4,6-trinitrotoluene (235 kJ mol⁻¹). The weakest bond of the other compounds may be the C NO₂ bond or the N N bond, and the strength of the N N bond is related to the nitro group on azole ring.     

15N NMR spectra and reactivity of 2,4,6‐triazidopyridines, 2,4,6‐triazidopyrimidine and 2,4,6‐triazido‐s‐triazine

2,4,6‐Triazido‐s‐triazine, 2,4,6‐triazidopyrimidine and six different 2,4,6‐triazidopyridines were studied by ¹⁵N NMR spectroscopy. The assignment of signals in the spectra was performed using the gauge‐independent atomic orbital (GIAO)–Tao‐Perdew‐Staroverov‐Scuseria exchange‐correlation functional (TPSS)h/6‐311+G(d,p) calculations on the M06‐2X/6‐311+G(d,p) optimized molecular geometries. The Truhlar and coworkers' continuum solvation model called SMD was applied to treat solvent effects. With this approach, the root mean square error in estimations of the ¹⁵N chemical shifts for the azido groups was just 1.9 ppm. It was shown that the different reactivity of the α‐ and γ‐azido groups in pyridines correlates well with the chemical shifts of the N_α signals of these groups. Of two nonequivalent azido groups of azines, the azido group with the most shielded N_α signal is the most electron‐deficient and reactive toward electron‐rich reagents. By contrast, the azido group of azines with the most deshielded N_α signal is the most reactive toward electron‐poor reagents. Copyright © 2013 John Wiley & Sons, Ltd.