- Mechanisms of Heptane Degradation and Product Formation in Microwave Discharge
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Abstract: A mechanism for the degradation of n-heptane and the formation of the products of its plasma-chemical transformation by microwave discharge treatment has been proposed. Chemical reactions resulting in reactive species, namely free radicals that form lower hydrocarbons and polyaromatic structures are presented. The product composition of the gas, liquid, and solid phases has been studied using gas chromatography–mass spectrometry analysis of the precipitate obtained by evaporation of the liquid phase after the treatment of n-heptane.
- Bobkova,Stokolos,Garifullin
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p. 336 - 340
(2019/08/15)
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- An esterification and purifying and cleaning production process (by machine translation)
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The invention relates to a production process of esterification purifying and cleaning. The invention using nano solid acid catalyst to catalyze the esterification reaction in order to improve the reaction activity, and membrane separation technology follow-up of the refining process, including washing and water washing, catalyst separation and decompression dealcoholization. The refining process to realize the whole process continuous, automatic operation, high production efficiency, product quality is stable. The catalyst separation process with the esterification reaction process in a system coupled to the same, the fine suspended state and the catalyst in the separation and recovery process the loss in serious problems. Membrane separation of low energy consumption, octanol high recovery efficiency. (by machine translation)
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Paragraph 0018; 0019; 0020; 0021; 0023; 0024; 0025-0031
(2017/05/23)
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- Solvent-free facile synthesis of di-octyl phthalate over heterogeneous sulfated zirconia acid catalyst
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The present study reports the synthesis of di-octyl phthalate (DOP), widely used as a plasticizer, via solvent-free esterification of phthalic acid and n-octanol over sulfated zirconia (SZr) heterogeneous acid catalyst. A comparison with other heterogeneous acid catalysts such as K-10 acid activated clay, zeolites (β and Y), Amberlyst-15 resin shows the superior activity of SZr, exhibiting maximum conversion of n-octanol (88%) with 93% DOP selectivity at 160 °C in 6 h. The rate of the reaction for SZr catalyst is computed as 17.3 mmol h?1 g?1. The catalyst activity is stable upon recycling for up to five cycles. The weak acid sites of the catalyst are postulated as the responsible active centres involved in the reaction. The reaction has been successfully scaled up over twenty five times; and the product DOP (67 g, 99% by GC) isolated and characterized by FT-IR and 1H NMR spectroscopy. It is noteworthy that the activity of SZr catalyst is comparable with that of H2SO4 and p-toluene sulphonic acid (p-TSA), which clearly suggets its potential as an efficient alternative to conventional commercial homogeneous acid catalysts for the synthesis of DOP.
- Parmar, Ajay M,Saravanan,Tyagi, Beena,Srinivasan, Kannan
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p. 747 - 755
(2017/08/04)
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- NOVEL SINGLE STEP ESTERIFICATION PROCESS OF ALDEHYDES USING A HETEROGENEOUS CATALYST
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The present invention relates to a novel simple, efficient and single-step process for esterification of aldehydes using a heterogeneous catalyst with high yields. More particularly, the present invention relates to a novel simple, efficient and single-step process for esterification of aldehydes using Titanium superoxide with greater than 80% yields.
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Page/Page column 20
(2016/06/20)
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- Titanium superoxide-a stable recyclable heterogeneous catalyst for oxidative esterification of aldehydes with alkylarenes or alcohols using TBHP as an oxidant
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Titanium superoxide efficiently catalysed the oxidative esterification of aldehydes with alkylarenes or alcohols, under truly heterogeneous conditions, to afford the corresponding benzyl and alkyl esters in excellent yields. Mechanistic studies have established that this "one pot" direct oxidative esterification process proceeds through a radical pathway, proven by a FTIR spectral study of a titanium superoxide-aldehyde complex as well as spin trapping experiments with TEMPO. The intramolecular version of this protocol has been successfully demonstrated in the concise synthesis of 3-butylphthalide, an anti-convulsant drug.
- Dey, Soumen,Gadakh, Sunita K.,Sudalai
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p. 10631 - 10640
(2015/11/17)
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- Sulfonated graphene as highly efficient and reusable acid carbocatalyst for the synthesis of ester plasticizers
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Plasticizers are well known for their effectiveness in producing flexible plastics. The automotive, plastic and pharmaceutical industries, essential to a healthy economy, rely heavily on plasticizers to produce everything from construction materials to medical devices, cosmetics, children toys, food wraps, adhesives, paints, and 'wonder drugs'. Although H2SO4 is commonly used as commodity catalyst for plasticizer synthesis it is energy-inefficient, non-recyclable, and requires tedious separation from the homogeneous reaction mixture resulting in abundant non-recyclable acid waste. In this study, for the first time, we report an efficient synthesis of ester plasticizers (>90% yields) using sulfonated graphene (GSO3H) as an energy-efficient, water tolerant, reusable and highly active solid acid carbocatalyst. The hydrothermal sulfonation of reduced graphene oxide with fuming H2SO4 at 120°C for 3 days afforded GSO3H with remarkable acid activity as demonstrated by 31P magic-angle spinning (MAS) NMR spectroscopy. The superior catalytic performance of GSO3H over traditional homogeneous acids, Amberlyst-15, and acidic ionic liquids has been attributed to the presence of highly acidic and stable sulfonic acid groups within the two dimensional graphene domain, which synergistically work for high mass transfer in the reaction. Furthermore, the preliminary experimental results indicate that GSO3H is quite effective as a catalyst in the esterification of oleic and salicylic acid and thus may pave the way for its broad industrial applications in the near future.
- Garg, Bhaskar,Bisht, Tanuja,Ling, Yong-Chien
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p. 57297 - 57307
(2015/02/02)
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- Efficient synthesis of symmetrical phthalate and maleate diesters using phosphinite ionic liquids
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Symmetrical dialkyl phthalates and maleates were synthesized using phosphinite ionic liquid as a catalyst and reaction medium. The results indicated that phosphinite ionic liquid shows better catalytic and reusable performance without using any acid or base catalyst. Under the optimum conditions, using 1-methyl-3-(4-phosphinitebutyl) imidazolium chloride as catalyst, the conversion of phthalic and maleic anhydrides to the corresponding diesters of primary and secondary alcohols was occurred in 72-85% yields. The diesters of tertiary alcohols and phenols could not be prepared by this method. A kind of widely used plasticizer, dioctyl phthalate, was prepared in good yield under these conditions. The ionic liquid could be reused three times after easy separation from the products without any disposal. Iranian Chemical Society 2012.
- Valizadeh,Khalili
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p. 529 - 534
(2013/02/22)
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- SO42-/SnO2: Efficient, chemoselective, and reusable catalyst for acylation of alcohols, phenols, and amines at room temperature
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SO42-/SnO2 was employed for the acylation of a variety of alcohols, phenols, and amines under solvent-free conditions at room temperature. This method showed preferential selectivity for acetylation of the amino group in the presence of a hydroxyl group. The reported method is simple, mild, and environmentally viable, using several other acid anhydrides at room temperature. Copyright Taylor & Francis Group, LLC.
- Satam, Jitendra R.,Gawande, Manoj B.,Deshpande, Sameer S.,Jayaram, Radha V.
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p. 3011 - 3020
(2008/02/12)
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- Process for producing carboxylic acid esters and catalysts therefor
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A process for producing carboxylic acid esters by the following steps: a) preparation of a reaction mixture containing an alcohol and a carboxylic acid and/or a carboxylic anhydride and/or a carboxylic acid ester and or a partially esterified carboxylic acid, b) heating of this mixture to the suitable reaction temperature in the presence of a solid polysiloxane insoluble in the reaction medium and having sulphonic acid groups with intensive thorough mixing accompanied by continuous separation of the reaction water which forms, wherein the polysiloxane used as the catalyst in modified by treatment with a soluble aluminum, titanium or zirconium compound, and the spherical particles thereof have a diameter of 0.01 to 3 mm, a specific surface of 0.1 to 1200 m2 /g, a specific pore volume of 0.01 to 6.0 ml/g and a bulk density of 50 to 1000 g/l.
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- Montmorillonite clay catalysis. Part 10. K-10 and KSF-catalysed acylation of alcohols, phenols, thiols and amines: Scope and limitation
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Montmorillonite K-10 and KSF are highly efficient catalysts for the acetylation of a variety of alcohols, thiols, phenols and amines with acetic anhydride. Amino groups can be selectively acetylated in the presence of hydroxy groups, while the hydroxy groups can be preferentially acetylated in the presence of thiol groups. No selectivity is observed between primary and secondary hydroxy groups in the presence of K-10 and KSF. The catalysts are found not to be efficient for acetylation of tertiary alcohols. This method is simple and convenient with minimum environmental impact. The catalysts are also effective for the acylation of alcohols, thiols, phenols and amines with acetyl chloride and benzoyl chloride. Cyclic anhydrides such as succinic anhydride, maleic anhydride and phthalic anhydride and p-toluene sulfonyl chloride show less reactivity than acetic anhydride and acyl chlorides.
- Li, Tong-Shuang,Li, Ai-Xiao
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p. 1913 - 1917
(2007/10/03)
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- Method for producing a purified ester
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A method for producing an ester, which comprises reacting an organic acid or its anhydride with an alcohol in the presence of a catalyst of an organometallic compound, wherein an esterification reaction product containing the catalyst, is treated with a polyhydric alcohol.
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- The Esterification of Carboxylic Acid with Alcohol over Hydrous Zirconium Oxide
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The esterification of carboxylic acids with alcohols proceeded efficienly with hydrous zirconium oxide to give the corresponding esters in the vapor phase, in the liquid phase, and in an autoclave.The steric hindrance of carboxylic acids and alcohols affected the esterification by lowering the reactivity.With a rise in the reaction temperature, the conversion of the carboxylic acid increased.The dehydration of alcohols was prevented by using hydrous zirconium oxide in spite of the high reaction temperature.The reaction rate is first-order with respect to the concentration of the catalyst and an alcohol and is inversely proportional to thta of the carboxylic acid.Transesterification also proceeded efficiently.
- Takahashi, Kyoko,Shibagaki, Makoto,Matsushita, Hajime
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p. 2353 - 2361
(2007/10/02)
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- Monoazo pigments containing barbituric acid derivatives
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A monoazo pigment of the formula STR1 wherein R1 denotes a halogen atom or an alkyl or alkoxy group containing 1-4 carbon atoms, R2 denotes a H atom, an alkyl group containing 1-4 carbon atoms or a phenyl group, X denotes a --NH-- or --CH2 O group, Y denotes an O atom or S atom or an imino group and Z denotes an O atom or an imino group are prepared. The pigments may be used to color high molecular weight organic materials such as polyamides, polyesters and polyolefins. The pigments possess excellent fastness to light, weathering and migration.
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- Quinolone-azo-acetoacetamino quinolone pigments
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Azo pigments of the formula STR1 wherein Q, X, Y and Z represent hydrogen or halogen atoms, alkyl or alkoxy groups of 1 to 4 carbon atoms, aryl or aryloxy groups which can be substituted by halogen atoms or alkyl or alkoxy groups of 1 to 4 carbon atoms, and wherein Q and X and Y and Z can also be closed via vicinal carbon atoms to form an isocyclic ring which are useful for pigmenting printing dyes and high molecular organic material.
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- Dicarboxylic acid ester diazo pigments
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Diazo pigments of the formula STR1 wherein R denotes an alkyl, cycloalkyl, aralkyl, aryl or heterocyclic radical, X denotes a hydrogen or halogen atom, an alkyl or alkoxy group containing 1 to 4 carbon atoms, or a nitro, cyano, trifluoromethyl or carboxylic acid ester group, and Y denotes a hydrogen or halogen atom, an alkyl or alkoxy group containing 1 to 4 carbon atoms or a nitro, cyano, trifluoromethyl or carboxylic acid ester group, are useful for coloring plastics and printing inks in fast yellow to orange shades.
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- Tetracarboxylic acid ester substituted disazo pigments
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A compound of the formula STR1 in which A represents phenylene which may be substituted by chlorine, bromine, methyl, methoxy, ethoxy or cyano, X represents hydrogen or chlorine, and R represents methyl or ethyl, was prepared. The compounds are useful for pigmenting high molecular organic materials such as polyamides, polyurethanes and polyesters. The compounds have excellent fastness to light, migration, weather and to alkali.
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- Isoindolinone compounds useful in preparing heavy metal containing pigments
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Isoindolinone pigments of the formula STR1 wherein M denotes a polyvalent metal atom other than an alkaline earth, R denotes an organic radical, X denotes an O or S atom or an imino group, X1 and Y1 denote H or halogen atoms, alkyl, alkoxy, alkoxycarbonyl, alkylsulphonyl or alkylcarbamoyl groups containing 1-6 C atoms, or nitro, carbamoyl or aralcarbamoyl groups, or the radicals X1 and Y1 form a fused benzene ring, X2 denotes an H atom, Y denotes a halogen atom and Z denotes a nitro, a carbamoyl or phenylcarbamoyl group, an alkylcarbamoyl group having 2-6 C atoms, or a group of the formula R1 Y2, wherein R1 represents an H atom, an alkyl or cycloalkyl group containing 1-6 C atoms or an aralkyl or aryl group and Y2 represents an O or S atom, m denotes 0-4, n denotes 0-4 and p denotes 0-3 and the sum of m+n+p must be 4, are useful for coloring plastics and lacquers in yellow to orange shades of excellent fastness properties.
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- Monoazo pigments containing barbituric acid or thio- or imino-derivatives thereof
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Monoazo pigments of the formula STR1 wherein R1 denotes a H atom, an alkyl group containing 1-4 C atoms or an aryl radical, R2 denotes a H atom, an alkyl group containing 1-4 C atoms, or an aralkyl or aryl radical, or wherein the radicals R1 and R2, conjointly with the N atom, form a heterocyclic 5-membered or 6-membered ring, R3 denotes an H atom or halogen atom or an alkyl group containing 1-4 C atoms, R4 and R5 denote H atoms, alkyl groups containing 1-4 C atoms or phenyl groups optionally substituted by halogen atoms and alkyl and alkoxy groups containing 1-4 C atoms, X denotes an O atom or an imino group, Y denotes an O atom or S atom or an imino group, and Z denotes a halogen atom, an alkyl or alkoxy group containing 1-4 C atoms, or an aryloxy group, and wherein the carbonamide group is located in the m- or p-position to the azo group are prepared. The compounds are useful for coloring high molecular organic materials such as aminoplast, alkyl resins, polystyrene and polyvinyl chloride. The pigments show very good fastness to light and migration.
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- Disazo pigments containing naphthalene coupling components
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Disazo pigments of the formula STR1 wherein R1 is 2-nitro-5-chlorophenyl or 1-nitronaphthyl-2, R2 is naphthalene in which the azo, hydroxyl and --CO--group are in the 1,2,3-position and R4 is a phenylene or naphthalene group are prepared. The disazo pigments may be used for pigmenting high molecular organic materials such as cellulose ethers, polyamides, polyurethanes and acrylic. The pigments have very good fastness to migration, heat and to light.
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- 6-Methylbenzimidazolonylazobarbituric acid pigment
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A monoazo pigment of the formula STR1 wherein R1 denotes a halogen atom or an alkyl or alkoxy group containing 1 - 4 carbon atoms, R2 denotes a H atom, an alkyl group containing 1 - 4 carbon atoms or a phenyl group, X denotes a --NH-- or --CH2 O group, Y denotes an O atom or S atom or an imino group and Z denotes an O atom or an imino group are prepared. The pigments may be used to color high molecular weight organic materials such as polyamides, polyesters and polyolefins. The pigments possess excellent fastness to light, weathering and migration.
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- Disazo pigment containing at least 2 chlorine atoms and process for their manufacture
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A disazo pigment of the formula STR1 WHEREIN X and Y are hydrogen, chlorine, alkyl of 1 - 4 C-atoms or one of X and Y can be alkoxy of 1 - 4 C-atoms and Z is chlorine or methyl, which is useful for pigmenting high molecular organic material and shows excellent fastness to light and weather.
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- Manufacture of alkyl esters of polycarboxylic acids
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A method of making alkyl esters of polycarboxylic acids by reacting an alkaline salt of the acid and at least one halo-alkane so that the rate of conversion is limited to 35- 85% whereby no partial esters are formed.
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- Bis-2-azomethine pigments, process for their manufacture and their use
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Bis-azomethine pigments of the formula SPC1 Wherein X denotes an aromatic radical on which the imino groups are in the o-position, Y denotes a hydroxyl, alkoxy, cycloalkoxy, aralkoxy or aryloxy, amino, alkylamino or arylamino group and Z denotes a H or halogen atom or an alkoxy, nitro or nitrile group, the radical X having to be free of nitro groups if Y denotes an arylamino group and Z denotes a H atom, as well as metal complexes of these bis-azomethines are useful for coloring plastics and lacquers in yellow to red shades of good fastness properties.
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- Metal complex pigments
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Metal complex pigments of the formula SPC1 Wherein X and Y denote hydrogen or halogen atoms or alkyl or alkoxy groups containing 1-4 C atoms and V and Z denote hydrogen or halogen atoms, nitro groups or alkyl, alkoxy or alkylsulphonyl groups containing 1-6 atoms, the two radicals V and Z can furthermore form a fused benzene ring and M represents a polyvalent metal atom, except an alkaline earth metal atom which are useful for pigmenting high molecular organic material.
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- Iminoisoindolenine pigments, process for their manufacture and their use
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Iminoisoindolenine pigments of the formula SPC1 Wherein R represents a phenylene or diphenylene radical, X represents a hydrogen or halogen atom, Y represents an alkyl, alkoxy, alkanoylamino or alkylsulphonyl group containing 1 to 4 carbon atoms, a nitro group, a phenyl, benzoylamino, phenoxy or phenylsulphonyl group which may be substituted by halogen atoms, alkyl or alkoxy groups of 1 to 4 carbon atoms, X1 represents a hydrogen or halogen atom, an alkyl or alkoxy group of 1 to 4 carbon atoms, an alkoxycarbonyl group of 2 to 6 carbon atoms, a nitro, trifluoromethyl, carbamoyl or cyano group, Y1 represents a halogen atom, an alkyl or alkoxy group of 1 to 4 carbon atoms or a trifluoromethyl group, Z represents a --NHCO or NHCONH group, m is 1 to 4, n is 0 to 2, and p is 0 to 1, the sum of m + n being 4, are useful for coloring plastics and lacquers in yellow shades of excellent fastness properties.
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