- Method for preparing 4,6-diamino resorcinol hydrochloride by resorcinol one-pot method
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The invention discloses a method for preparing 4,6-diamino resorcinol hydrochloride by a resorcinol one-pot method. The method comprises the following steps of (1) uniformly mixing and dissolving methanesulfonic acid, an acylation reagent and resorcinol a
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Paragraph 0016-0021
(2018/07/30)
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- Preparation method of 4,6-diamidoresorcinol or salts thereof
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The invention discloses a preparation method of 4,6-diamidoresorcinol or salts thereof, which comprises the following steps: carrying out nitro reduction on 2-chloro-4,6-dinitroresorcinol in an alcohol-water medium by using a palladium-carbon catalyst, an
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Paragraph 0017; 0018; 0019
(2017/03/08)
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- Benzo [1,2-d:5,4-d '] b (oxazole) - 2,6-di-thiol and its preparation method
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The invention discloses benzo [1, 2-d: 5, 4-d']-di-(oxazole)-2, 6-dithiol and a preparation method thereof. The preparation method comprises the steps as follows: resorcinol is taken as a raw material, zinc chloride is taken as a catalyst, resorcinol and zinc chloride react with acetic oxide to obtain 4, 6-diacetylresorcinol; 4, 6-diacetylresorcinol reacts with hydroxylamine hydrochloride in sodium hydroxide to obtain 4, 6-di-[(1Z)-N-hydroxyethyliminumacyl]benzene-1, 3-diphenol; 4, 6-di-[(1Z)-N-hydroxyethyliminumacyl]benzene-1, 3-diphenol is taken as a raw material and subjected to Beckmann rearrangement reaction in a polyphosphoric acid system to obtain DAR*HCl; and DAR*HCl is taken as a raw material and reacts with carbon disulfide in a potassium hydroxide solution to obtain a target compound. According to the invention, sulfydryl is introduced at 2 and 6 sites simultaneously, the product is prepared through multiple steps of reaction, the method is simple, convenient and easy to operate, the melting point of the product is higher than 300 DEG C, and the yield is high.
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Paragraph 0013; 0024-0026
(2018/09/02)
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- One-pot synthesis preparation 4,6-diaminoresorcinol method of hydrochloride
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The invention discloses a method for preparing 4,6-diaminoresorcinol dihydrochloride through one-pot synthesis. The method mainly comprises the steps of: by taking Bronsted acid such as polyphosphoric acid, concentrated sulfuric acid or methanesulfonic acid as the catalyst and the solvent, realizing oximation, Beckmann rearrangement, hydrolysis and hydrocchlorination of 4,6-diacetylresorcinol, and thus obtaining the 4,6-diaminoresorcinol dihydrochloride (DAR.2HCl), wherein the mol ratio of hydroxylamine hydrochloride, the Bronsted acid catalyst and the 4,6-diacetylresorcinol is (2.0-2.5)/(1-10)/1, and the reaction temperature ranges from 65 to 125 DEG C. The method provided by the invention is simple in process steps and efficient in preparation; therefore, the industrialization of the 4,6-diaminoresorcinol dihydrochloride is greatly promoted.
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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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- An efficient synthesis of 2,6-disubstituted benzobisoxazoles: New building blocks for organic semiconductors
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(Chemical Equation Presented) 2,6-Disubstituted benzobisoxazoles have been synthesized by a highly efficient reaction of diaminobenzene diols with various orthoesters. The scope of this new reaction for the synthesis of substituted benzobisoxazoles has been investigated using four different orthoesters. The utility of these compounds as building blocks for the synthesis of conjugated polymers is demonstrated.
- Mike, Jared F.,Makowski, Andrew J.,Jeffries-El, Malika
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supporting information; experimental part
p. 4915 - 4918
(2009/05/31)
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- Production method of 4,6-diaminoresorcin
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The present invention relates to a novel production method of 4,6-diaminoresorcin, and to 2-sulfonic acid-4,6-dinitroresorcin as its intermediate and salts thereof. The target compound is obtained by (R1) sulfonating resorcin (A) to obtain resorcin 2,4,6-trisulfonate (B), (R2) nitrating the compound (B) to obtain 2-sulfonic acid-4,6-dinitroresorcin (C), (R3) hydrolyzing the compound (C) to obtain 4,6-dinitroresorcin (D), and finally (R4) reducing the compound (D) to obtain 4,6-diaminoresorcin (E):
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Page column 13-15
(2010/01/31)
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- Process for preparation of 4,6-diaminoresorcinol or salts thereof
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The invention relates to a process for preparation of 4,6-diaminoresorcinol or salts thereof by reducing 4,6-bis(substituted)phenylazoresorcinol expressed by the formula [1]wherein, R denotes a halogen atom, an alkyl group having 1-5 carbon atoms, a hydroxycarbonyl group or an alkoxy group having 1-5 carbon atoms, n denotes 0 or any integer of 1-5, and two or more groups R may be same or different each other,for example, 4,6-bisphenylazoresorcinol, with hydrogen in the presence of a metal catalyst to obtain 4,6-diaminoresorcinol or salts thereof, characterized in that an aliphatic nitrile compound (for example, acetonitrile) is used as a solvent, or characterized in that the reduction is carried out by using at least one organic solvent selected from aliphatic nitrile compounds, aliphatic alcohols having 3-5 carbon atoms, dioxane and ethylene glycol monomethyl ether, etc. as a solvent and furthermore in the presence of a filter aid (for example, active carbon). According to the said preparation process, 4,6-diaminoresorcinol with high purity can be easily obtained from 4,6-bis(substituted)phenylazoresorcinol in a high yield.
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- Process for producing 4,6-diaminoresorcinols
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A process for producing 4,6-diaminoresorcinols comprises the steps of: subjecting a dioxime of the formula (4) STR1 wherein R is an alkyl or phenyl group, to Beckmann rearrangement to thereby produce 4,6-diacylaminoresorcinol of the formula (5) STR2 wherein R is as defined above, and subjecting the 4,6-diacylaminoresorcinol to hydrolysis and recovering the product 4,6-diaminoresorcinol (6) STR3 or a salt thereof.
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- Process for the preparation of 4,6-diaminoresorcinol
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4,6-diaminoresorcinol can be prepared in a plurality of steps in such a way that a) 1,3-dichlorobenzene is nitrated with a mixed acid of HNO3, H2 SO4 and SO3 at 0 to 40° C. in anhydrous H2 SO4, b) the resulting 1,3-dichloro-4,6/2,4-dinitrobenzene isomeric mixture is first reacted with benzyl alcohol in the presence of a strong base at -15° C. to +15° C. and then at 20° to 40° C. to give the dibenzyloxy compound and c) the 1,3-dibenzyloxy-4,6-dinitrobenzene isomer arising in pure form in b) is converted to the 4,6-diaminoresorcinol by catalytic hydrogenation.
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- Preparation of 4,6-diaminoresorcinol through a bisazoarylresorcinol intermediate
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The present invention is a method of preparing a 4,6-bisarylazoresorcinol comprising reacting an aryldiazonium salt and resorcinol in the presence of a base and a reaction medium containing water and a water-miscible solvent at a temperature in the range
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- Process for the preparation of diaminoresorcinol
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The present invention relates to a method of preparing 4,6-diaminoresorcinol from 1,2-dichloro-3,5-dinitrobenzene comprising the steps of: (a) contacting 1,2-dichloro-3,5-dinitrobenzene with a hydroperoxide in the presence of anhydrous base to form 2,
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- Synthesis of diaminoresorcinal from resorcinol
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The invention relates to a novel process for preparing 4,6-diaminoresorcinol, a precursor to polybenzoxazole, from resorcinol according to the following scheme. STR1 Resorcinol (I) is reacted with a di-tert-alkylating reagent to form a 4,6,-di-tert-alkylresorcinol (II), which is then halogenated to form a 2-halo-4,6-di-tert-alkylresorcinol (III). The 2-halo-4,6-di-tert-alkylresorcinol is nitrated in one of two ways to form a 2-halo-4,6-dinitroresorcinol (IV), which is then hydrogenated to from the 4,6-diaminoresorcinol. The invention also relates to a novel chemical composition-2-halo-4,6-di-tert-alkylresorcinol (III )--and a process for preparing same.
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- Cleaving arylethers
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The present invention relates to a method of cleaving arylethers such as arylethers represented by the formula: STR1 wherein R is hydrogen, C1 -C6 alkyl, cycloalkyl, phenyl, substituted phenyl or CH=CH2 ; each A is independently NO2, hydroxy, halo, or methoxy; n is an integer from 0 to 5; and x is 1 or 2, comprising contacting the arylether with an amide hydrohalide salt under conditions sufficient to cleave the ether group(s) of the arylether and form a phenol or substituted phenol. The present invention also relates to a method of preparing 4,6-diaminoresorcinol, which is a monomer used for making polybenzoxazoles (PBO).
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- Process for the preparation of diaminoresorcinol
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A method of producing 4,6-diaminoresorcinol comprising a) reducing a dinitroarylether of the formula: STR1 wherein R is hydrogen, C1 -C6 alkyl, cycloalkyl or CH=CH2, R' is hydrogen or CH2 --R, each A is independ
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- Synthesis of 4,6-diaminoresorcinol
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The invention is a new process for preparing 4,6-diaminoresorcinol, a precursor to polybisbenzoxazoles. The desired product is prepared from resorcinol by incorporating a halo group on the 2-position of resorcinol to form 2-haloresorcinol, then nitrating
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- 1,3-di-arylmethoxy-4,6-dinitro-benzenes, process for their preparation and process for the preparation of 4,6-diaminoresorcinol
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The new 1,3-di-arylmethoxy-4,6-dinitrobenzenes of the formula STR1 in which R1 and R2 independently of one another denote hydrogen or C1 -C4 -alkyl and Ar represents C6 -C12 -aryl, can be prepared by reaction of 1,3-dihalogeno-4,6-dinitro-benzenes of the formula STR2 in which Hal represents chlorine or bromine, with an arylmethanol of the formula in which R1, R2 and Ar have the said meaning, and a strong base in the temperature range from 0° to 100° C. These di-arylmethoxy-dinitro-benzenes can be converted into 4,6-diaminoresorcinol by catalytic reduction with hydrogen.
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