- Method for simultaneously preparing 2-methyl resorcinol and 4-methyl resorcinol
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The invention provides a method for simultaneously preparing 2-methyl resorcinol and 4-methyl resorcinol, and belongs to the technical field of organic synthesis. The method comprises the following steps: resorcinol and methanol are subjected to an alkylation reaction through a metal phosphate stationary phase catalyst, and 2-methyl resorcinol and 4-methyl resorcinol are obtained. According to the method, the metal phosphate is used as the catalyst, the 2-methyl resorcinol and the 4-methyl resorcinol can be obtained at the same time by controlling the type of the catalyst, the resorcinol conversion rate is high, the joint selectivity of the 2-methyl resorcinol and the 4-methyl resorcinol can reach 60% at most, the selectivity of other products, namely intermediate hydroxyanisole is about 30%, the selectivity of m-xylylene dimethyl ether is about 5%, and the obtained products are all important intermediates for fine chemical engineering, organic chemistry and drug synthesis and are high in economic benefit. Meanwhile, methanol is used as a methylation reagent, so that the method is environment-friendly and low in price, and the production cost is reduced.
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Paragraph 0034-0066
(2022/01/10)
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- Synthesis method of 2,6-dihydroxytoluene
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The invention belongs to the technical field of organic chemical synthesis, and particularly relates to a synthesis method of 2,6-dihydroxytoluene. The synthesis process comprises the following steps: S1, mixing 2,6-dihalogenated toluene, alkali, a heavy metal salt catalyst and an adsorbent, and heating and hydrolyzing to obtain a salt solution of 2,6-dihydroxytoluene; S2, adjusting the pH value of the 2,6-dihydroxytoluene salt solution obtained in the previous step to be weakly acidic by using an acid, separating a separated solid, and purifying to obtain a pure product of 2,6-dihydroxytoluene. The adopted main raw materials, such as 2,6-dichlorotoluene, cuprous chloride, sodium dodecyl sulfate and potassium hydroxide, are common chemical raw materials in the market, and are cheap, easy to obtain and wide in source; the synthesis route is short, steps are few, operation is simple, and production cost is greatly saved; reaction conditions are mild, and industrial production is facilitated; the process route is less in three wastes, the catalyst and the adsorbent can be repeatedly used, emission of the three wastes is further reduced, and the method is environment-friendly; the yield of the whole route is high, and the cost advantage is remarkable.
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Paragraph 0047-0049
(2021/11/27)
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- Method for synthesizing M-hydroxyanisole
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The invention provides a method for synthesizing M-hydroxyanisole. Belong to organic synthesis technical field. The synthesis method comprises the following steps: a vapor phase mixture of resorcinol and methanol is subjected to alkylation reaction through a metal phosphate - alumina fixed phase catalyst to obtain m-hydroxyanisole. The method adopts the gas-solid phase alkylation method to synthesize the M-hydroxyanisole without separating the reaction product from the catalyst, has the characteristic of continuous reaction, and can realize continuous production in the industrial production process. The method utilizes the acid-base catalytic activity center on the surface of the stationary phase catalyst to catalyze the reaction of resorcinol and methanol, and has high resorcinol conversion rate. The method has the advantage of high selectivity of m-hydroxyanisole. Methanol is used as a methylation reagent, and the method is environmentally friendly, low in cost and high in economic benefit.
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Paragraph 0032-0033; 0052-0053; 0056-0057; 0060-0063
(2021/11/03)
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- Method for continuously producing 2, 6-dihydroxytoluene
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The invention discloses a method for continuously producing 2, 6-dihydroxytoluene. According to the method, 3-chloro-2-methylaniline is taken as a raw material, diazotization is carried out through a micro-channel reactor to synthesize an intermediate 3-chloro-2-methylphenol, and then 2, 6-dihydroxytoluene is synthesized. According to the method, the micro-channel reactor is used for diazotization of 3-chloro-2-methylaniline so that severe heat release and unstable properties of the product in the reaction process can be effectively avoided, the retention time is short, the next reaction is directly carried out after the reaction is finished, the continuous reaction can be experimented, the yield of the diazotization step can be increased to 85-95% from the traditional 75-85%, the total yield of the 2, 6-dihydroxytoluene is increased to 80-90%, and the product purity can be up to more than or equal to 99.0%.
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- Method for synthesizing 2,6-dihydroxytoluene by using waste acid
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The invention discloses a method for synthesizing 2,6-dihydroxytoluene by using waste acid mechanically. According to the method, 3-chloro-2-methylaniline is taken as a raw material, an intermediate 3-chloro-2-methylphenol is synthesized through diazotization and hydrolysis, the reaction is optimized in the alkali fusion, acidification and refining processes, the mechanical application of waste acid and a solvent in the reaction and the optimization of a refining scheme are emphatically optimized, the yield is effectively improved, three wastes are reduced, and 2,6-dihydroxytoluene is synthesized. The method provided by the invention greatly reduces the generation of acidic wastewater, better meets the requirement of environmental protection, and effectively increases the yield of the product, and the quality of the product reaches 99.0-99.5%.
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- Synthesis method of 2, 6-dihydroxytoluene
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A synthetic method of 2, 6-dihydroxytoluene comprises the following steps: adding 3-chloro-2-methylphenol, a sodium formate solution, cuprous chloride, sodium hydrosulfite and a caustic soda flake solution into a high-pressure kettle, performing nitrogen replacement, heating to 195-200 DEG C, keeping the temperature for 1.5 hours, cooling to 110 DEG C, pressing into an acidification kettle, washing the kettle with water to obtain an alkali melt, and merging into the acidification kettle; adding water into the alkali melt in the acidification kettle, dropwise adding hydrochloric acid until thepH value is 2-3, cooling to 30 DEG C, filtering, adding sodium chloride and ethyl acetate into the filtrate, and stirring; standing for layering, removing a water layer, stirring an organic layer andwashing with a 75% sodium carbonate solution, standing for layering, and removing a water layer,; removing ethyl acetate from an organic phase, adding toluene for dehydration, cooling, centrifuging, adding water, and refining to obtain a finished product. The method is reasonable in synthesis process and low in cost, the water layer (namely wastewater) generated in the production process is recycled after distillation, the production cost is saved, waste gas is recycled through condensation, pollution to the environment is greatly reduced, and the environment is protected.
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Paragraph 0010-0012
(2020/09/16)
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- Preparation method of 2,6-dihydroxytoluene
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The invention discloses a preparation method of 2,6-dihydroxytoluene. The preparation method comprises the following steps of dissolving prepared 3,5-diamino-4-methylbenzoic acid in water, adding dilute sulphuric acid, stirring uniformly, adding ZnCl2, reducing the temperature to minus -2 to 2 DEG C after stirring uniformly, dropwise adding a sodium nitrite solution into the mixture, continuouslystirring to react for 5-6 hours after the dropwise adding is finished, then adding water and dilute sulphuric acid, mixing uniformly, then heating for boiling, reacting for 30-45 minutes, then addingsodium hydroxide, carrying out reflux reaction for 1-2 hours, cooling to room temperature, adding diethyl ether, stirring for 20-40 minutes, then adding zeolite, stirring and mixing for 1-2 hours, carrying out reduced-pressure distillation after filtering, and preparing the 2,6-dihydroxytoluene. The preparation method disclosed by the invention has the beneficial effects that the raw-material costis low, the operation is simple, safe and reliable, the requirements for the environmental conditions are mild, the product purity is high and the yield is high.
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Paragraph 0022-0030; 0031-0039; 0040-0048; 0049-0066
(2018/04/27)
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- Method for preparation of 2, 6-dihydroxytoluene
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The invention relates to a method for preparation of 2, 6-dihydroxytoluene. The method comprises (1) methylation reaction: carrying out a methylation reaction process on resorcinol as a raw material, a certain amount of methanol as a solvent and a methylation reagent in the presence of a solid acid as a catalyst in a fixed bed reaction device, (2) distillation: carrying out reduced pressure distillation on the reaction liquid, recovering the solvent and collecting a crude product of 2, 6-dihydroxytoluene, and (3) purification: carrying out recrystallization on the crude product of 2, 6-dihydroxytoluene to obtain a refined product of 2, 6-dihydroxytoluene. The method improves the quality of the product, reduces environmental pollution, reduces a cost, is simple in operation, realizes clean and eco-friendly product production and is suitable for mass production.
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Paragraph 0051-0063
(2017/08/28)
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- A 2,6-di-hydroxy toluene synthesis method
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The invention discloses a synthesis method for 2, 6-dihydroxytoluene. According to the method, the 2, 6-dihydroxytoluene is obtained from 3-chloro-2-methylaniline is used as raw materials through diazotization reaction, lanthanum phosphate catalysis hydrolysis, alkali dissolution and acidification. The synthesis method has the advantages that (1) the raw material resources are wide; (2) the process is simple, and the operation is easy; (3) active rear earth is used as catalysts, and the color and luster of products can be optimized; (4) the reaction conditions are relatively mild, and the safety factor is high; (5) the total yield is as high as more than 65 percent, the purity reaches more than 99.0 percent, in addition, solvents can be recovered and reused, and the energy-saving and emission-reduction effects are obvious.
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Paragraph 0046-
(2017/03/08)
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- Reaction-activated palladium catalyst for dehydrogenation of substituted cyclohexanones to phenols and H2 without oxidants and hydrogen acceptors
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It is widely believed that the dehydrogenation of organic compounds is a thermodynamically unfavorable process, and thus requires stoichiometric oxidants such as dioxygen and metal oxides or sacrificial hydrogen acceptors to remove the hydrogen from the reaction mixture to drive the equilibrium towards the products. Here we report a previously unappreciated combination of common commercial Pd/C and H2 which dehydrogenates a wide range of substituted cyclohexanones and 2-cyclohexenones to their corresponding phenols with high isolated yields, with H2 as the only byproduct. The reaction requires no oxidants or hydrogen acceptors because instead of removing the generated hydrogen with oxidants or hydrogen acceptors, we demonstrated it can be used as a cocatalyst to help power the reaction. This method for phenol synthesis manifests a high atom economy, and is inherently devoid of the complications normally associated with oxidative dehydrogenations.
- Zhang, Jingwu,Jiang, Qiangqiang,Yang, Dejun,Zhao, Xiaomei,Dong, Yanli,Liu, Renhua
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p. 4674 - 4680
(2015/07/27)
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- The phototransformation of 4-chloro-2-methylphenoxyacetic acid under KrCl and XeBr excilamps irradiation in water
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The effect of UV radiation of a KrCl and a XeBr on the photodegradation of 4-chloro-2-methylphenoxyacetic acid (MCPA) was studied. The main photoproducts were identified by gas chromatograph/mass spectrometry (GC/MS). The variation of chlorine-ion and active chlorine in MCPA aqueous solution exposed to excilamp radiation was also defined by analytical methods. Irradiation of MCPA solution with a KrCl excilamp emitting mainly at 222 nm yield 2-methylhydroquinone and lactone of 2-hydroxy-3-methyl-5-chlorophenoxyacetic acid as the main photoproducts. Irradiation of MCPA solution with a XeBr excilamp emitting mainly at 283 nm yield 2-methylhydroquinone as the main photoproduct. Biological processes are not suitable for MCPA removal due to low or total absence of biodegradability of this class of pollutants. Estimation of biodegradability of phototreated MCPA solution was carried out according to ratios of biological oxygen demand (BOD5) to chemical oxygen demand (COD). The biodegradability of MCPA solutions increased after irradiation.
- Tchaikovskaya, Olga N.,Karetnikova, Elena A.,Sokolova, Irina V.,Mayer, Georgy V.,Shvornev, Dmitry A.
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experimental part
p. 8 - 14
(2012/04/10)
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- PROCESS FOR STRAIGHTENING KERATIN FIBRES WITH A HEATING MEANS AND DENATURING AGENTS
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The invention relates to a process for straightening keratin fibres, comprising: (i) a step in which a straightening composition containing at least two denaturing agents is applied to the keratin fibres, (ii) a step in which the temperature of the keratin fibres is raised, using a heating means, to a temperature of between 110 and 250° C.
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- One step hair coloring compositions using salts
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A hair coloring composition comprising the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an amino phenol, a naphthol, a polyhydric phenol, a catechol and mixtures thereof; wherein the composition comprising one or more oxidative hair coloring agents further comprises al least one water soluble carbonate releasing salts; and optionally a water soluble ammonium salt, is described.
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- Transition metal complexes as dye forming catalysts in hair coloring compositions
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A hair coloring composition comprising a first composition which comprises: (a) a dye forming transition metal salt or complex; which is first applied to the hair; and a second composition which comprises the following two compositions which are mixed just prior to application to the hair: (a) a composition comprising a water-soluble peroxygen oxidizing agent; and (b) a composition comprising one or more oxidative hair coloring agents selected from the group consisting of an aromatic diamine, an aminophenol, a polyhydric phenol a catechol and mixtures thereof.
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- Polymer electrolyte and process for producing the same
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A polymer electrolyte having, in a main chain, a structural unit represented by the following formula (1):-[Ar1-(SO2-N-(X+)-SO2-Ar2)m-SO2-N-(X+)-SO2-Ar1-O]- wherein Ar1 and Ar2 independently represent a divalent aromatic groups, m represents an integer of 0 to 3, and X+ represents an ion selected from hydrogen ion, an alkali metal ion and ammonium ion, which is excellent in proton conductivity, thermal resistance and strength. The polymer electrolyte is soluble in solvents and has excellent film forming property and recycling efficiency.
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- Process for producing 2-methyl-1,3-cyclohexanedione and 2-methylresorcinol
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A process for producing 2-methyl-1,3-cyclohexanedione which comprises subjecting 1,3-cyclohexanedione, formaldehyde and a dialkylamine to Mannich reaction to obtain a 2-dialkylaminomethyl-1,3-cyclohexanedione, and subjecting the 2-dialkylaminomethyl to hydrogenolysis, and a process for producing 2-methylresorcinol which comprises aromatizing 2-methyl-1,3-cyclohexanedione obtained. According to these processes, it is possible to produce high-purity 2-methylresorcinol and 2-methyl-1,3-cyclohexanedione commercially easily and advantageously.
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- Facile demethylation of aryl methyl esters with pyridiniumhydrobromide perbromide
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Pyridiniumhydrobromide perbromide (Py+HBr3-) demethylates methoxyanilines, methoxybenzoic acids, 3,4,5-trimethoxybenzoic acid, methoxy nitrobenzene, methoxynaphthalines and guaiacol to the corresponding phenols in quantitative yields.Demethylation of the methoxy group substituted at aryl part of isatin nucleus furnish the required hydroxy group.
- Ijaz, A. S.,Alam, M.,Ahmad, B.
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p. 288 - 289
(2007/10/02)
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- Meerwein-Ponndorf-Verley-Type Reduction of Dicarbonyl Compounds to Hydroxy Carbonyl Compounds and α,β-Unsaturated Carbonyl Compounds to Allylic Alcohols Catalyzed by Zirconocene and Hafnocene Complexes
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Group IVA metallocene complexes such as bis(η5-cyclopentadienyl)zirconium dihydrides, Cp2ZrH2 (1), and hafnium dihydrides, Cp2HfH2 (8), catalyze the chemoselective reduction of polycarbonyl compounds to hydroxy carbonyl compounds.For instance, the reduction of keto aldehydes 3-ketobutanal (2g) and 2-phenyl-2-ketoethanal (2h) proceeded selectively at aldehyde group to provide the corresponding hydroxy ketones 3g and 3h in 91percent and 93percent yields, respectively.Under similar conditions, however, cyclohexanediones were easily aromatized to benzenediols.On the other hand, 1 and 8 also catalyze the selective 1,2-reduction of various types of α,β-unsaturated carbonyl compounds, giving the corresponding allylic alcohols in good to excellent yields.Thus, steroidal dicarbonyl compounds, having an enone framework in their molecules Δ4-androstene-3,17-dione (11a) and Δ4-progestene-3,20-dione (11b) were reduced by 1 to 17-hydroxy-Δ4-androsten-3-one (12a) and 20-hydroxy-Δ4-progest-3-one (12b), which are essential human hormones, in 80percent and 67percent yields, respectively.
- Nakano, Tatsuya,Umano, Shigetoshi,Kino, Yoshio,Ishii, Yasutaka,Ogawa, Masaya
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p. 3752 - 3757
(2007/10/02)
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- Process for the preparation of resorcinol derivatives
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2-Substituted-4,6-di-t-butylresorcinol represented by the general formula: STR1 wherein R represents a straight or branched alkyl group having 1 to 20 carbon atoms, a straight or branched alkenyl group having 2 to 20 carbon atoms and at least one double bond, or an aralkyl group, but the tertiary carbon atom of R is free from direct bonding to the benzene nucleus, is prepared by allowing 4,6-di-t-butylresorcinol to react with a halogen compound represented by the general formula: wherein R has the same meaning as defined above, and X represents a halogen atom, excluding the X bonded to the tertiary carbon of R, in an aqueous alkali solution. By further debutylization of the 2-substituted-4,6-t-butylresorcinol, 2-substituted resorcinol represented by the general formula: STR2 wherein R has the same meaning as defined above, but the tertiary carbon of R is free from direct bonding to the benzene nucleus, is prepared.
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- A Nouvel Route to Resorcinols
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Hydroxylation of para-alkylated or 2,6-dialkylated phenols by hydrogen peroxide in SbF5-HF yields resorcinols, the electrophile reacting with the O-protonated substrate.
- Gesson, Jean-Pierre,Jacquesy, Jean-Claude,Jouannetaud, Marie-Paule
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p. 1128 - 1129
(2007/10/02)
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- Hydrolysis of toluene diamines to produce methyl resorcinols
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Methyl resorcinols are produced by the hydrolysis of toluene diamines in an aqueous excess of ammonium bisulfate. The reactants are contacted at an elevated temperature for a period of time sufficient to hydrolyze the toluene diamines to methyl resorcinols. The methyl resorcinols so produced are separated from the reaction mixture. The ammonium sulfate is regenerated to ammonium bisulfate by removing the water and thermally decomposing the by-product ammonium sulfate at an elevated temperature.
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