Abstract: The present invention provides a process for producing an oxide from an alcohol compound, the process comprising the steps of causing silica gel to carry the alcohol compound thereon and an oxidative catalyst thereon, and oxidizing the alcohol compound in the presence of an oxidizing agent, giving an oxide higher in oxidizing degree than the alcohol compound, and also provides a process for producing an oxide from an alcohol compound, the process comprising the steps of causing silica gel to carry the alcohol compound, and subjecting the alcohol compound to an electrolytic oxidation, giving an oxide higher in oxidizing degree than the alcohol compound.

Abstract: A new process for the production of triiodotrimesic acid that is used as an intermediate product for the synthesis of x-ray contrast media is described.

Abstract: A process for producing phenylacetic acid is provided. The process includes combining sodium, chlorobenzene, toluene, and a catalyst to form a suspension. This suspension is mixed to form phenylsodium. Upon boiling, the suspension forms benzylsodium. The suspension is then carbonized and acidified to form phenylacetic acid.

Abstract: This invention relates to a process for the manufacture of aromatic carboxylic acids by exothermic liquid phase oxidation of an aromatic feedstock. More particularly, this invention relates to the efficient energy recovery of the exotherm produced by the liquid phase oxidation of an aromatic feedstock. An apparatus useful in recovery of energy from the preparation of aromatic carboxylic acids by the exothermic liquid phase reaction of an aromatic feedstock is described where the primary means of energy recovery is by raising moderate pressure steam. This is coupled with a process to recovery low temperature energy using a process commonly known as an organic Rankine cycle and/or a heat pump. The combination of energy recovery methods increases the overall energy recovery and enables the recovery of reaction energy as either thermal energy (steam) or work or a combination of both.

Abstract: The present invention relates to a process for the preparation of 2-halo-6-nitrobenzoic acids by oxidation of 2-halo-6-nitro-benzyl alcohols, esters, ethers, or mixtures thereof with nitric acid and to the use of this process as a step in the preparation of 2-halo-6-nitrobenzoic acids from 2-halo-6-nitrotoluenes.

Abstract: The present invention provides a process for producing an oxide from an alcohol compound, the process comprising the steps of causing silica gel to carry the alcohol compound thereon and an oxidative catalyst thereon, and oxidizing the alcohol compound in the presence of an oxidizing agent, giving an oxide higher in oxidizing degree than the alcohol compound, and also provides a process for producing an oxide from an alcohol compound, the process comprising the steps of causing silica gel to carry the alcohol compound, and subjecting the alcohol compound to an electrolytic oxidation, giving an oxide higher in oxidizing degree than the alcohol compound.

Abstract: A process for the production of an aromatic carboxylic acid comprising contacting in the presence of a catalyst, within a continuous flow reactor, one or more precursors of the aromatic carboxylic acid with an oxidant, such contact being effected with said precursor(s) and the oxidant in an aqueous solvent comprising water under supercritical conditions or near supercritical conditions close to the supercritical point such that said one or more precursors, oxidant and aqueous solvent constitute a substantially single homogeneous phase in the reaction zone, wherein the contact of at least part of said precursor with said oxidant is contemporaneous with contact of said catalyst with at least part of said oxidant.

Abstract: The present invention provides an improved process for the production of benzaldehyde with 40-50% selectivity by the catalytic liquid phase air oxidation of toluene using a composite catalytic system comprising salts of iron, cobalt, manganese, molybdenum or nickel as recyclable catalyst, salts of manganese or copper as recyclable co-catalyst and cobalt bromide, sodium bromide, sodium chloride and zinc bromide as promoter.

Abstract: This invention is related to the production of trimellitic anhydride (TMA). More specifically, the invention is related to the addition of a mineral acid or salt thereof in the production process of trimellitic anhydride to reduce the viscosity of the bottoms fraction when TMA is purified by distillation and thus to prevent fouling/plugging. This permits the use of lower levels of TMA in the bottoms fraction and increases TMA recovery.

Abstract: A process for the oxidation of an alkyl-aromatic compound, wherein the aromatic compound is admixed with an oxidising agent or sulfur compound in the presence of an ionic liquid is described. In this process, air, dioxygen, peroxide, superoxide, any other form of active oxygen, nitrite, nitrate, nitric acid or other oxides (or oxyhalides) of nitrogen (hydrate or anhydrous) are preferably used as the oxidising agent. The process is usually under Bronsted acidic conditions. The product of the oxidation reaction is preferably a carboxylic acid or ketone or an intermediate compound in the oxidation such as an aldehyde, or alcohol. The oxidation is preferably performed in an ionic liquid containing an acid promoter such as methanesulfonic acid.

Abstract: Process for producing mono- and poly-carboxylic aromatic acids wherein an aromatic compound having at least one oxidizable substituent directly linked to the carbon atom of the corresponding aromatic nucleus is oxidized in the presence of a catalyst system in the liquid homogenous phase. The oxidation reaction is carried out in aqueous acetic acid, and the catalyst system consists of a combination of cobalt and zirconium organic salts. The oxidation reaction is carried out at an absolute pressure lower than 10 bar and at a temperature of 90-150° C.

Abstract: The present invention provides an improved process for the preparation of 2-aryl propionic acid which by subjecting an aryl compound selected from an aryl alcohol or aryl halide or an aryl olefin to carbonylation in the presence of a halide source, a protonic acid, water and a heterogeneous metal and a phosphine ligand as a catalyst in an organic solvent.

Abstract: In the presence of (1) an oxidizing catalyst comprising an imide compound such as N-hydroxyphthalimide, or (2) an oxidizing catalyst comprising such imide compound and a transition metal element-containing compound as a co-oxidizing agent (e. g., oxides, halides, complexes, hetero polyacid salts) a hydrocaron, an alcohol, an aldehyde, or a ketone as a substrate is brought into contact with molecular oxygen for oxidation. In the above-described oxidation process, the water content of the oxidizing reaction system is 200 mol or lower relative to 1 mol of the imide compound. According to the present invention, a substrate is efficiently oxidized with molecular oxygen under mild conditions, and there can be obtained the object compound(s) of high quality.

Abstract: A composition containing isomeric mixtures of arylaldehydes prepared from a mixed alkyl aromatic feedstock. A composition containing isomeric mixtures of dimethylbenzaldehydes prepared from a mixed xylene feedstock using a Gatterman-Koch type reaction. A composition of isomeric mixtures of tolualdehydes prepared from a toluene feedstock using a Gatterman-Koch type reaction.

Abstract: This invention relates generally to the oxidative carbonylation of toluene, catalyzed by rhodium or iridium complexes in the presence of an oxidant and under mild conditions, whereby toluic acid is produced with para-selectivity up to 98%.

Abstract: A process for preparing substituted aromatic and heteroaromatic aldehydes or carboxylic acids of the formula in which R1 and R2 are H, C1-C4 alkyl, C1-C4 alkoxy, OH, NO2, CN, COOH, CONH2, COOR, NH2, SO3H or halogen and R is C1-C4 alkyl and where R1 and R2 are not simultaneously H, X is C or N and Z is CHO or COOH, from the corresponding symmetric stilbene compounds of the formula in which R1, R2 and X are as defined above, by aqueous ozonolysis and subsequent isolation of an aldehyde or oxidation to give the corresponding carboxylic acid.

Abstract: Disclosed is an improved process for the continuous production of aromatic carboxylic acids by the liquid-phase oxidation of an alkyl aromatic compound with an oxygen-containing gas in the presence of oxidation catalyst which results in reduced wastewater generation, reduced condensing capacity requirements, and, optionally, increased power recovery, and. The process effectively utilizes the heat of reaction in the process of removing excess water generated from the reaction and minimizes the loss of solvent used as the carrier for the reaction catalyst by removing reactor off-gas directly into a water removal column for distillation. A portion of the overhead aqueous vapors are removed from the top of the water removal column as a vapor distillate, with the remaining overhead aqueous vapors being condensed then subsequently refluxed to the fractionating zone of the water removal column.

Abstract: A process for producing a polycarboxylic acid which comprises performing liquid phase oxidation of polyalkyl-substituted aromatic aldehyde and/or oxide derivative of polyalkyl-substituted aromatic aldehyde as raw material for oxidation with molecular oxygen at two stages in water solvent in the presence of a catalyst comprising bromine or both bromine and a heavy metal(s) at a temperature of 180 to 280 ° C., thereby producing trimellitic acid or pyromellitic acid, wherein said liquid phase oxidation is performed in a continuous operation at the first stage and in a continuous operation or in a batch operation at the second stage and a total amount of bromine in said catalyst is divided to add separately at each the first stage and the second stage.

Abstract: The present invention relates to a process for the preparation of a carboxylic acid of the formula III, 1

Abstract: Compositions and methods for inhibiting scale are provided. Pursuant to the present invention, a composition for inhibiting scale is provided that includes a carbohydrate polymer having both nitrogen-containing groups and carboxyl groups. The nitrogen-containing groups include amino groups, amido groups and mixtures thereof. The present invention has been found useful for inhibiting scale in industrial waters, such as, pulp bleach plant process waters which contain calcium oxalate and barium sulfate scale.

Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.

Abstract: Citalopram can be industrially and economically produced and at a high yield by reacting a compound of the following formula [VI] with 3-(dimethylamino)propyl chloride in the presence of at least one of N,N,N′,N′-tetramethylethylenediamine and 1,3-dimethyl-2-imidazolidinone and a condensing agent. The compound of the following formula [III], which is a key compound for the production of citalopram, can be easily produced by subjecting the compound of the following formula [II] to reduction and cyclization.

Abstract: A new composition of matter for a diamidodiol and a method for preparing the diamidodiol. The exemplary diamidodiol has the formula C15H30N2O4 and is prepared by reacting a first quantity of 2-amino-2-methyl-1-propanol with a second quantity of a di-substituted malonyl dichloride (i.e., diethylmalonyl dichloride), preferably in ethyl acetate as solvent. A tetraamido macrocycle is prepared from the diamidodiol in two steps by oxidizing the diamidodiol to form a diacid followed by coupling using a known procedure of the diacid with an aryl diamine (e.g., 1,2-diaminobenzene) to yield the tetraamido macrocycle.

Abstract: A method for oxidizing an alkane, comprising the step of oxidizing said alkane with oxygen in the presence of an aldehyde, a copper-based catalyst and a nitrogen-containing compound. This method may be used to convert alkanes to corresponding alcohols and ketone having pharmaceutical activities, etc.

Abstract: This invention relates to a method for producing a partially oxidized organic compound, e.g., an unsaturated aldehyde/carboxylic acid having three or more carbon atoms, or an organic acid anhydride/nitrile compound having four or more carbon atoms. This method requires a catalyst prepared by treating a carrier in such a manner that water used in the treatment achieves specific resistance.

Abstract: A process for purifying a naphthalenic carboxylic acid comprising contacting at a temperature below about 575° F. a mixture comprising an impure naphthalenic carboxylic acid and a solvent in the presence of hydrogen gas with a noble metal on carbon catalyst. The process results in reduced amounts of organic impurities in the purified acid when compared to other purification processes.

Abstract: The invention relates to a process for preparing a compound of the formula (I) 1

Abstract: A process for preparing an aromatic carboxylic acid having improved purity comprising contacting at an elevated temperature and pressure a mixture comprising an impure aromatic carboxylic acid and a solvent in the presence of hydrogen gas with a carbon catalyst which is essentially free of a hydrogenation metal component.

Abstract: The invention is directed to a process for the production of terephthalic acid and esters thereof from p-tolualdehyde or mixtures of p-tolualdehyde and p-xylene. The process of the invention can be carried out at lower temperatures and faster throughput than conventional processes using p-xylene. The use of p-tolualdehyde facilitates safety considerations by eliminating the induction period and high oxiding fluid concentrations encountered in typical oxidation reactions which use only p-xylene as the terephthalic acid or ester precursor.

Abstract: The invention relates to compounds of formula (I) ##STR1## wherein R.sub.1 is an electronegative substituent, preferably nitro, cyano, formyl or carboxy, R.sub.2 is --A--R.sub.4, wherein A is a branched or straight chain C.sub.1-9 alkylene and R.sub.4 is carboxy or 5-tetrazolyl; R.sub.3 is an electronegative substituent, preferably nitro, cyano, halogen, formyl, carboxy, C.sub.1-5 alkyl carbonyl, aryl carbonyl or SO.sub.2 R.sub.6, wherein R.sub.6 is a branched or straight chain C.sub.1-5 alkyl, aryl alkyl, aryl or NR.sub.7 R.sub.8, wherein R.sub.7 and R.sub.8 are independently hydrogen, a branched or straight chain C.sub.1-5 alkyl or together form a C.sub.3-6 ring; or a pharmaceutically acceptable ester or salt thereof. The compounds are peripheral, long acting COMT (catechol-O-methyl transferase) inhibitors and are useful, e.g., in the treatment of Parkinson's disease and hypertension.

Abstract: A process for producing aromatic carboxylic acids efficiently by operating a distillation column for separating the vaporized reaction solvent and other useful ingredients from an oxidation reactor while permitting efficient energy recovery without causing any obstruction to turbine and without causing any clogging of the distillation column, said process comprising oxidizing an alkyl aromatic compound in a liquid reaction solvent comprising an aliphatic carboxylic acid with a molecular oxygen-containing gas in the presence of an oxidation catalyst in the said oxidation reactor to form an aromatic carboxylic acid, guiding the oxidation reactor exhaust gas into the distillation column to subject it to a distillation, passing the distilltion overhead gas to a condenser to form a condensate, which is returned to the distillation column, and to generate a steam on the shell side, which is guided to a steam turbine for energy recovery, and burning the condenser exit gas in order to drive a gas turbine for energy r

Abstract: Disclosed is a method for preparing isophthalic acid from metaxylene and especially for purifying crude isophthalic acid (IPA) produced in the course of such method, or otherwise, from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials. The purifying portion of the method comprises the step of: (1) filtering the dispersion to form a crude IPA filter cake; (2) dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution; (3) crystallizing purified IPA from the solution in the crystallization solvent by reducing the temperature, or pressure, or both of the solution; (4) separating the crystallized purified IPA from the solution; and (5) re-dissolving or soaking the washed purified IPA cake at elevated temperature, to remove the final traces of the crystallization solvent and obtain the desirable particle sizes and shape.

Abstract: A process for producing terephthalic acid and/or dimethyl terephthalate includes contacting a toluene-containing reaction stream with a first catalyst under toluene disproportionation conditions to produce an intermediate product stream of para-xylene with negligible ortho-xylene. The first catalyst includes a crystalline molecular sieve which has an ortho-xylene diffusion rate of at least 50 minutes. The first catalyst can be modified by selectivation with a silicon compound or carbon compound. The intermediate product stream, without need for para-xylene purification, is oxidized to terephthalic acid or dimethyl terephthalate.

Abstract: The invention is directed to a simple process for the preparation of the product 2-carboxy-5-nitrobenzenesulfonic acid (=4-nitro-2-sulfo-benzoic acid) or a salt thereof. The product can be prepared by the oxidation reaction of 2-methyl-5-nitrobenzenesulfonic acid with metal hypochlorites in the presence of metal bases from the group consisting of hydroxides and carbonates, essentially with the exclusion of heavy metal salts.

Abstract: The present invention relates to a TEMPO-catalyzed oxidation of primary alcohols, RCH.sub.2 OH to corresponding carboxylic acids, RCOOH in the presence of catalytic in the presence of catalytic amount of NaClO and stoichiometric amount of NaClO.sub.2 as an oxidant.

Abstract: A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the pressure and temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone.

Abstract: A substrate (e.g., a cycloalkane, a polycyclic hydrocarbon, an aromatic compound having a methyl group) is oxidized with oxygen in the presence of an oxidation catalytic system comprising an imide compound of the following formula (1) (e.g., N-hydroxyphthalimide) and a co-catalyst containing a element selected from Group 3 to 12 elements (in particular, Group 4 to 11 elements) of the Periodic Table of Elements. The co-catalyst comprises a compound containing plural elements (except heteropolyacid and a combination of Group 7 and 8 elements of the Periodic Table of Elements), and is useful for the formation of an oxide (e.g., a ketone, an alcohol, a carboxylic acid): ##STR1## wherein R.sup.1 and R.sup.2 represent a substituent such as a hydrogen atom or a halogen atom, or R.sup.1 and R.sup.2 may together form a double bond or an aromatic or nonaromatic 5- to 12-membered ring, X is O or OH, and n is 1 to 3.

Abstract: Process for the preparation of 3-phenylpropionic acid in which 3-phenylpropanal is subjected to an oxidation, at elevated temperature, in particular at a temperature of between 40.degree. and 80.degree. C., using a medium containing molecular oxygen. A high degree of conversion and a high selectivity are obtained. The starting material 3-phenylpropanal can be prepared in a suitable manner through the hydrogenation of cinnamaldehyde in the presence of a Pd-containing catalyst, after which the reaction mixture obtained can without intermediate further processing be used in the oxidation reaction. The combination of the two process steps constitutes a simple, commercially attractive process for the preparation of 3-phenylpropionic acid using cinnamaldehyde as a starting material. 3-phenylpropionic acid can be used in particular in the preparation of pharmaceuticals such as HIV protease inhibitors.

Abstract: A process for preparing a compound of formula (I), ##STR1## where R.sup.1 is optionally substituted alkyl or phenyl, R.sup.2 is COOH, and R.sup.3 and R.sup.4 are independently selected from hydrogen, halo, haloalkyl, nitro, hydroxy, alkoxy, haloalkoxy or alkoxyalkoxy; which process comprises oxidising a compound of formula (II) ##STR2## where R.sup.1, R.sup.3 and R.sup.4 are as defined in relation to formula (I) and R.sup.5 is H, halo or C.sub.1-4 alkyl with sodium hypochlorite or sodium chlorite in the presence of a catalytic amount of a ruthenium or palladium compound and a phase transfer catalyst in an organic solvent at a pH of 7-11.

Abstract: A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone.

Abstract: (1) CF.sub.2 .dbd.CFO(CF.sub.2).sub.n COOR is allowed to react with chlorine or bromine to obtain CF.sub.2 XCFXO(CF.sub.2).sub.n COOR', (2) which is allowed to react with a Grignard reagent MgBrC.sub.6 H.sub.3 (CH.sub.3).sub.2 to convert the terminal group to --COC.sub.6 H.sub.3 (CH.sub.3).sub.2, (3) followed by reaction with diethylaminosulfur trifluoride to convert --COC.sub.6 H.sub.3 (CH.sub.3).sub.2 to --CF.sub.2 C.sub.6 H.sub.3 (CH.sub.3).sub.2, (4) followed further by oxidation of the resulting methyl group and by esterification to convert the methyl group to --CF.sub.2 C.sub.6 H.sub.3 (COOR).sub.2 and (5) followed by dechlorination or debromination to obtain CF.sub.2 .dbd.CFO(CF.sub.2).sub.n CF.sub.2 C.sub.6 H.sub.3 (COOR).sub.2. The resulting bifunctional vinyl ether compound having an aromatic ring is a novel compound and can be used as a copolymer component for fluorine-containing elastomers.

Abstract: The invention relates to novel processes for the preparation of phenyl acetic acid derivatives of the formula (I) some of which are known ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 independently of each other each represent hydrogen, alkyl or alkoxy by ozonolysis of compounds of the formula (II) ##STR2## in which R.sup.4 represents hydrogen or methyl and oxidation of the reaction products obtained therefrom. The invention further relates to novel intermediates and a process for the preparation thereof.

Abstract: A catalyst system and process for the oxidative cleavage of alkenes with hydrogen peroxide is provided. The catalyst system comprises a source of ruthenium, a source of molybdenum and a phase transfer agent. The process comprises contacting an alkene with the hydrogen peroxide in the presence of the above catalyst system. Sources of ruthenium and molybdenum comprise the metals, salts or complexes. Preferred sources are RuCl.sub.3 and MoO.sub.3. The phase transfer agent is preferably a quaternary ammonium salt. The process usually takes place in the presence of an organic solvent, preferably t-butanol.

Abstract: A process for preparing aromatic carboxylic acids by the exothermic liquid-phase oxidation reaction of an aromatic feedstock compound, wherein energy is efficiently recovered from the exothermic oxidation reaction.

Abstract: Fluro-substituted aromatic carboxylic acids, and particular 2- and 4-fluorobenzoic acid can be made from the corresponding fluoro-methyl compound such as fluorotoluene in a single stage by the reaction at elevated temperature, preferably of at least 80.degree. C. with hydrogen peroxide and bromide in mole ratios to the substrate of greater than 2:1, and preferably around 3:1, in the presence of means capable of generating bromine free radicals from bromine molecules, such as radiation having a wavelength of not greater than 600 nm or an organic peroxide.

Abstract: A process for the controlled oxidation of alkyaromatic compounds comprises reacting said compounds with an oxidising system, comprising cobalt (II) ions, bromide ions, and hydrogen peroxide, in the presence of an appropriate protic solvent.The process is particularly useful in the selective oxidation of poly(alkyl)aromatic compounds.

Abstract: A process for the manufacture of aromatic dicarboxylic acids is disclosed using a low bromine to metals ratio facilitated by the use of cerium along with the cobalt and manganese catalyst. Aromatic dicarboxylic acids such as terephthalic acid are useful in the manufacture of fiber, films, bottles and molded products.

Abstract: A process for preparing a pyrazolecarboxylic acid compound of the formula (II): ##STR1## wherein Y and Z each represent a hydrogen, a halogen, a nitro, a cyano, COOR.sub.1, NR.sub.1 R.sub.2, CONR.sub.1 R.sub.2, SR.sub.1, SO.sub.2 NR.sub.1 R.sub.2, SO.sub.2 R.sub.3, R.sub.3 CO, OR.sub.4, CHX.sub.2 or CX.sub.3 ; A represents a hydrogen, an alkyl having 2 to 4 carbons, a phenyl, a pyridyl or OR.sub.5 ; where R.sub.1 and R.sub.2 each represent a hydrogen or an alkyl having 1 to 10 carbons; R.sub.3 represents an alkyl having 1 to 10 carbons; R.sub.4 represents a hydrogen, an alkyl having 1 to 10 carbons, a phenyl, CHF.sub.2, CF.sub.3 or CF.sub.3 CH.sub.2 ; R.sub.5 represents an alkyl having 1 to 10 carbons; and X represents a halogen, which comprises oxidizing a pyrazole compound of the formula (I): ##STR2## wherein Y, Z and A have the same meanings as above, by contacting the compound of formula (I) with an oxygen-containing gas in the presence of a metal catalyst at 20.degree. to 200.degree. C.

Abstract: Acetic acid is recovered from the mother liquor used to oxidize para-xylene to terephthalic acid by adding at least one organic compound having a melting point below 140.degree. C. and an atmospheric boiling point above 230.degree. C.

Abstract: The invention relates to the new compound 1-aminomethylnaphthalene-6-sulphonic acid, a process for its preparation by amidoalkylation of naphthalene-2-sulphonic acid and hydrolysis of the amidoalkylation product, and its use as an intermediate product for the preparation of 6-hydroxynaphthalene-1-carboxylic acid.