Eine einfache Synthese des Cyclohexanon-2-carbonsäure-amids sowie dessen Reaktionen

A Simple Synthesis of Cyclohexanone-2-carboxamide and its Reactions By reaction of urea with cyclohexanone and subsequent acid hydrolysis cyclohexanone-2-carboxamide 2 is formed. 2 is C-alkylated by alkyl halides yielding compounds 6a—g . With amines, the enamines 10a and 10b , and with hydrazines the tetrahydroindazolones 8a and 8b are formed. 2 reacts with aqueous alkali to give pimelic acid. Cyclopentanone-2-carboxamide 3 and cycloheptanone-2-carboxamide 4 are formed in an analogous way.     

Zur Bromierung des Cyclohexanon-2-carbonsäureamids

The Bromination of Cyclohexanone-2-carboxamide Cyclohexanone-2-carboxamide with bromine forms 6-bromo-cyclohexanone-2-carboxamide ( 2 ) or 2-bromo-cyclohexanone-2-carboxamide ( 3 ). Via Faworski-rearrangement the reaction of 2 and ammonia or amines gives trans-cyclopentanedicarboxamides ( 5a – f ). 3 and thiourea form the aminothiazole derivative 6 . Pyridinium salt 7 is formed by reaction of 2 and pyridine. 7 and phenylhydrazine form the phenyl-indazolonoyl-hydrazine 8. 1 and sodiumhypochlorite yield 2-hydroxy-cyclohexanone-2-carboxamide ( 9 ).     

1-甲基-3-正丙基-4-氨基-5-吡唑羧酰胺的制备

1 甲基 3 正丙基 5 吡唑羧酸经硝酸 -浓硫酸硝化制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酸 ,收率 85 %;用氯化亚砜将其酰氯化制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酰氯 ,该吡唑羧酰氯与浓氨水反应制得 1 甲基 3 正丙基 4 硝基 5 吡唑羧酰胺 ,收率 90 %;硝基吡唑羧酰胺在乙醇中用氯化亚锡还原制得 1 甲基 3 正丙基 4 氨基 5 吡唑羧酰胺 ,收率 84%。研究了反应的较佳合成工艺条件 ,产品经TLC、IR及MS谱进行了结构表征。     

邻氯苯磺酰胺合成工艺改进

邻氯苯胺和盐酸以及哑硝酸钠反应生成重氮盐,重氮盐在催化剂存在下与二氧化硫进行反应,生成邻氯苯磺酰氯,磺酰氯再和氨水反应最终生成邻氯苯磺酰胺.收率为83.2%,纯度为99%.     

Die Nitril-Carboxamid-Umlagerung

The Nitrile Carboxamide Rearrangement By reaction of cyclohexanone-2-carboxamide ( 4 ) with cyan amide 1-cyano-cyclohex-1-en-2-yl-urea ( 6 ) is formed via nitrile carboxamide rearrangement. Whilst compound 6 with 1,2-diaminobenzene hydrochloride forms 11-amino-1 H-2,3,4,5-tetrahydrodibenzo[b,e][1,4]diazepin hydrochloride ( 8 and 8a ), compound 6 and 1,2-diaminobenzene form hexahydro-benzimidazo[1,2-c]-quinazolin-6-one ( 12 ). Compound 8 with sodium hydroxide yields 11-amino-1 H-2,3,4,11a-tetrahydrodibenzo[b,e]-[1,4]diazepin ( 9 ). Compound 6 reacts with cyclohexylamine to form N-(1-cyanocyclohex-1-en-2-yl)-N′-cyclohexyl urea ( 10 ). Compound 10 with 1,4- or 1,2-diaminobenzene hydrochloride yields compound 7 and 8 . In alkaline solution 10 cyclises to 4-amino-3-cyclohexyl-2,3,5,6,7,8-hexahydroquinazolin-2-one ( 11 ). Compound 4 and malonitrile form either 3-amino-4-cyano-1,2,5,6,7,8-hexahydro-isoquinol-1-one ( 13 ) or 1-amino-4-cyano-2,3,5,6,7,8-hexahydro-isoquinol-3-one ( 14 ). Compound 13 and alkaline formaldehyde react to cyanooctahydroisoquinoline-[2,3-c] [1,3,5]oxdiazin-6-one ( 17 ). 2-Cyanoethyl-cyclohexan-one-2-carboxamide ( 22 ), prepared by Michael-reaction from 4 and acrylonitrile, forms via nitrile carboxamide rearrangement 10-cyano-1,2,3,4,5,6,7,10-octahydroquinolin-2-one ( 24 ) and 2-(1′-cyano-cyclohexyl-2′-one)-propionic acid ( 25 ). Nucleophilic attack of the NH₂-group at the cyanogroup of compound 22 forms 5-(spirocyclohexan-2′-one)-hexahydropyridin-2,6-dione ( 27 ).     

Reactions with the Arylhydrazones of some α-cyanoketones

Ethereal diazomethane reacts with the arylhydrazones of mesoxalic acid dinitrile 1a–c and of ethyl α-cyanoglyoxalate 2b, d–g to yield the methylarylhydrazones 3a–c and 4a–e respectively. Treatment of 4b–e with phenylmagnesium bromide results in the formation of the imino derivatives 5a–d . Whereas 2a–g react with phenylhydrazine to yield the aminopyrazoles 8a–g , the hydrazides 10a, b are formed on treatment of 4c, e with hydrazine hydrate. 1a–c react with hydrazine hydrate and with phenylhydrazine to yield 3-amino-4-arylhydrazono-5-imino-2-pyrazoline derivatives 11a–f 11a, b react with acrylonitrile to yield 3-amino-1(β-cyanoethyl)-4-arylhydrazono-5-imino-2-pyrazoline derivatives 12a, b which can be readily cyclised to the pyrazolo[3,2-b]pyrimidine derivatives 13a, b by the action of hot acetic acid.     

Study of the reaction of resorcinol,formaldehyde, and ammonia

Latex dip adhesives for nylon and rayon tire cords are prepared by reacting resorcinol and formaldehyde in aqueous solution in the presence of a catalyst for a specified time and then adding a butadience–styrene–vinylpyridine latex. Ammonia improves the stability of the latex and increases the adhesion of rubber to cord. However, a white precipitate forms if ammonia is added before the resorcinol and formaldehyde have reacted sufficiently. This paper is study of the nature of this precipitate and the conditions for its formation. By measuring the heat of reaction of formaldehyde and ammonia and, subsequently, of mixtures of formaldehyde and resorcinol to which varying amounts of ammonia were added, information on the reaction mechanism has been obtained. Ammonia reacts rapidly with formaldehyde to form an unstable intermediate, presumably trimethylolamine, which then reacts further with resorcinol to form trisdihydroxybenzylamine. This compound is also very reactive and condenses withmore ammonia and formaldehyde to give a polymer of low solubility, the composition depending on the amounts of ammonia and formaldehyde available for reaction. Elemental analyses support this concept. Primary and secondary amines react in a maner similar to ammonia.     

Synthesis and some reactions of 1-(4.6-dimethoxybenzo-furanyl)- and 1-(4.6.7-trimethoxybenzofuranyl)butane-1.2.3-trione-2-arylhydrazones

Both 4.6-dimethoxy-( 1c ) and 4.6.7-trimethoxy-5-acetoacetylbenzofuran 1d are obtained from visnaginone ( 1a ) and khellinone methyl ethers 1b , respectively, by a CLAISEN condensation. The β-diketones 1c and 1d couple with aromatic diazonium compounds to form the hydrazones 2a – i . 1-(4.6-Dimethoxybenzofuranyl)- and 1-(4.6.7-trimethoxybenzofuranyl)butane-1.2.3-trione-2-arylhydrazones 2 a–i react with hydrazine hydrate in acetic acid to yield the corresponding pyrazole derivatives 3a–i or 4a–i . The monohydrazones 5a–b are isolated when 2e or 2i are treated with hydrazine hydrate in ethanol. The hydrazones are converted to the respective pyrazoles by the action of glacial acetic acid. Hydroxylamine hydrochloride reacts with 1.2.3-trione-2-arylhydrazones 2a, c, e, f and i to yield the corresponding isoxazole derivatives 6a–e or 7a–e . The 2-arylhydrazones 2a, c, d, e, h and i form the corresponding pyrazole derivatives 8a–f when treated with semicarbazide hydrochloride.     

电导滴定法测定浆料中对苯二甲酸含量

用氨水做溶剂,使对苯二甲酸溶解,并形成对苯二甲酸铵,用ＮａＯＨ标准溶液滴定ＮＨ＾＋４,通过计算 得对苯二甲酸的含量,本方法简便,准确,重现性和于浆料中对苯二甲酸含量的测定,结果令人满意。     

铵（氨）循环工艺的原理及应用

在化工生产中常需要使用酸碱参与反应,酸碱的消耗不仅增加了生产成本,还会排放含酸碱的废渣或废液而危害环境。铵（氨）循环工艺可作为解决上述问题的一个有效方法。在铵（氨）循环工艺中,铵（NH₄⁺）与某些物料反应,同时铵转化为氨（NH₃）;再用氨与物料反应,氨重新转化为铵,获得铵（氨）循环使用。铵（氨）循环反应结束后获得了产品,但铵和氨在工艺内循环使用,形成闭路循环,不仅避免了酸碱等物质的消耗和排放,甚至在某些情况下还能达到理论上100%的反应原子利用率。由于铵（氨）循环工艺绿色环保,可生产高附加值的产品,具有很高的工业应用价值。铵（氨）循环工艺在制备或提取纯碱、碳酸钙、氧化铝和氢氧化镁等领域已展示了独特的优势,介绍了氨（铵）循环工艺在化工领域的一些应用,以期让此工艺为更多产品的生产提供借鉴和参考。     

硫酸、氨管式反应器造粒技术及其应用实例

介绍硫酸、氨管式反应器造粒技术生产尿基复合肥。硫酸与氨在管式反应器充分反应,生成高温低湿硫酸铵料浆,该料浆均匀喷洒于造粒机内的物料表面,由于硫酸铵与其它肥料具有良好的配伍性,其包裹在尿素、磷铵外,使该技术有效解决了尿素磷铵等低共熔物生成给复肥生产带来的许多问题,故获得装置生产稳定、产品产量质量提高、能耗降低的效果。     

New insights into synthesis of nanocrystalline hexagonal BN

Uncovering the mechanism behind nanocrystalline hexagonal boron nitride (h-BN) formation at relatively low temperatures is of great scientific and practical interest. Herein, the sequence of phase transformations occurring during the interaction of boric acid with ammonia in a temperature range of 25–1000 °C has been studied in detail by means of thermo-gravimetric analysis, X-ray diffraction, infrared spectroscopy, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The results indicate that at room temperature boric acid reacts with ammonia to form an ammonium borate hydrate (NH₄)₂B₄O₇x4H₂O. Its interaction with ammonia upon further heating at 550 °C for 1 h leads to the formation of turbostratic BN. Nanocrystalline h-BN is obtained either during heating in ammonia at 550 °C for 24 h or at 1000 °C for 1 h. This result is important for the development of novel cost-effective and scalable syntheses of h-BN nanostructures, such as nanosheets, nanoparticles, nanofibers, and nanofilms, as well as for sintering h-BN ceramic materials.     

合成氨系统氨积累机理浅析及其改进措施

由于水煤气净化系统积累的氨与部分冷凝水在换热器管程内壁反应形成的盐溶液在管程内冷却结晶,造成变换工序阻力异常增大.增设氨分离装置,利用变换工序副产的低压蒸汽加热分解铵盐并汽提氨,可以有效解决铵盐结晶问题.     

Ternary nucleation: kinetics and application to water–ammonia–hydrochloric acid system

The ternary nucleation of an ideal mixture of three alcohols and a non-ideal mixture of water, ammonia and hydrochloric acid, which is relevant in atmosphere, have been investigated theoretically. In the ideal mixture of three alcohols, the nucleation rates obtained using simplified kinetic approach are compared with the nucleation rates given by a detailed kinetic model. The simplified model is seen to underestimate nucleation rates by 2–3 orders of magnitude. This is mainly due to the crude estimate for the Zeldovich factor in the simplified model. We have proposed a modification to the simplified model. The improved model gives order-of-magnitude estimates for the nucleation rates. The ternary nucleation of water–ammonia–hydrochloric acid is studied with the improved model. The results have been compared with binary nucleation of water and ammonium chloride. The results show that water–ammonia–hydrochloric acid mixture is effectively a two-component system.     

Reactions with 2-thiazolin 5-ones. IV. Action of amines on 4-substituted 2-alkoxy- and 2-benzylmercapto-2-thiazolin-5-ones

Whereas treatment of 2-butyloxy-, 2-pentyloxy- and 2-β-phenylethyloxy-4-arylazo-2-thiazolin-5-ones 1d–h with strong basic amines results in their rearrangement into 1-aryl- Δ²-1,2,4-triazolin-5-one-3-carboxylic acid derivatives 2 , the 2-isobutyloxy, 2-(2-octyloxy)- and the 2-cyclohexyloxy-4-arylazo-2-thiazoline-5-ones 1i–n rearrange upon treatment with the same reagents into Δ²- 1,2,4-triazoline-5-thione-3-carboxylic acid derivatives 3 . On the other hand, 1d–h,1 react with aromatic amines to give 1-aryl-2-alkoxy-1,2,4-triazole-3-carboxylic acid anilides 4a–i , via the loss of hydrogen sulphide. The phenylhydrazides 4j–l are obtained upon treatment of 1g, h,l with phenylhadrazine. Treatment of 4-arylidene-2-benzylmercapto-2-thiazolin-5-ones 6a–c with ammonia results in the formation of the thiohydantoin derivatives 7e, g . However, 6b, c react with phenylhydrazine to yield the phenylhydrazides 8b, c . The reaction of 6a–e with piperidine or morpholine involves to molecules of the reagent to yield 10a–d which are thermally cyclised to the thiazolone derivatives 11a–d .     

Über die Nitril-Carboxamid-Umlagerung und die Heterocyclenbildung aus 2-Cyancyclohexenylharnstoff

The Nitrile Carboxamide Rearrangement and the Formation of Heterocycles via Cyano-cyclohexenyl-urea Anthranilic amide and cyanogen bromide form Cyano-phenyl-urea ( 7 ) via Nitrile Carboxamide Rearrangement. Cyclisation of cyano-cyclohexenyl-urea ( 4 ) yields 4-amino-2,3,5,6,7,8-hexahydroquinazolin-2-one ( 10 ). 4 and amines form N-cyano-cyclohexenyl-N'-alkyl-ureas ( 11a–e ) or 3-alkyl-4-amino-hexahydroquinazolin-2-ones ( 12a–g ). 4 and α-aminoacids yield octahydro-imidazolo-quinazolindiones ( 14a–b ). Oxo-cyclohexane-2-carboxamide ( 1 ) and amino benzimidazole form hexahydrobenzimidazo-quinazolinone 17 .     

Selective Catalytic Reduction of NOx over H-ZSM-5 Under Lean Conditions Using Transient NH3 Supply

The selective catalytic reduction (SCR) of NO _x over zeolite H-ZSM-5 with ammonia was investigated using in situ FTIR spectroscopy and flow reactor measurements. The adsorption of ammonia and the reaction between NO _x , O₂ and either pre-adsorbed ammonia or transiently supplied ammonia were investigated for either NO or equimolar amounts of NO and NO₂. With transient ammonia supply the total NO reduction increased and the selectivity to N₂O formation decreased compared to continuous supply. The FTIR experiments revealed that NO _x reacts with ammonia adsorbed on Brønsted acid sites as NH₄ ⁺ ions. These experiments further indicated that adsorbed -NO₂ ^– is formed during the SCR reaction over H-ZSM-5.     

Characterization of penetrant interactions in Kapton polyimide using a gravimetric sorption technique

Sorption of pure anhydrous ammonia and pure sulfur dioxide in Kapton polymide has been measured at 30 and 35°C at subatmospheric pressures using a McBain quartz spring balance. The sulfur dioxide sorption and desorption was well described by the Fickian transport model; however, the ammonia sorption exhibited significant deviations from Fickian behavior. A substantial fraction of the initially sorbed ammonia remained in the film after extended periods under vacuum at 35°C. Infrared analysis of the treated film revealed the presence of new carbonyl and nitrogen–hydrogen stretching peaks characteristic of primary and secondary amides. These observations suggest that the ammonia reacts chemically with some of the imide linkages. Based on infrared analysis of the ammonia-exposed Kapton, heating the sample under vacuum at 120°C caused re-formation of most of the orginally disturbed imide structures, with attendant evolution of ammonia as a condensation product.     

水煤气净化系统氨积累处理方法

对水煤气净化系统氨积累成因进行分析,由于流体流动边界层的存在,氨与部分冷凝水在换热器管程内壁反应形成盐溶液并在管程内冷却结晶,从而造成铵盐结晶.从能量利用和水的平衡进行分析,提出改进措施,为合成氨装置技改提供参考.     

Preparation of manganese oxide–polyethylene oxide hybrid nanofibers through in situ electrospinning

Manganese oxide nanoparticles–polyethylene oxide nanofibers as organic–inorganic hybrid were prepared via in situ electrospinning. Thus, electrospinning of polyethylene oxide solution with different manganese chloride concentration was carried out in gaseous ammonia atmosphere containing oxygen. The reaction of manganese chloride with ammonia produces manganese hydroxide, and then oxygen in the reaction media reacts with manganese hydroxide to yield manganese oxide. These two reactions occur during fiber formation. Transmission electron microscopy and scanning electron microscopy showed that manganese oxide (MnO₂) nanoparticles were formed on the produced nanofibers of 100–600 nm in diameter. The existence of the formed MnO₂ was also proved by X‐ray diffraction analysis, and it showed that the λ‐MnO₂ nanoparticles were produced. Differential scanning calorimetry (DSC) analysis was used to determine the melting point and to calculate the crystallinity of the produced hybrid nanofibers. The DSC and thermogravimetric analysis results of the obtained nanofibers were compared with those of the nanofibers produced in electrospinning of pure polyethylene oxide solution. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010