Abstract: Improved process for the preparation of nitronaphthalene-sulphonic acids by reacting the corresponding naphthalene-sulphonic acids with nitric acid and working up the nitration mixture, characterized by the features that the reaction of the naphthalene-sulphonic acids with nitric acid is already interrupted before the nitration reaction has ended and that the nitration mixture is treated, optionally after dilution with water, with bases at a pH value of 5 to 14.

Abstract: Carboxylic acids and N-t.-alkylamines can be prepared simultaneously by the alkaline pressure hydrolysis of N-t.-alkyl carboxylic acid amides. A 5 to 50% strength by weight aqueous solution of an alkali metal hydroxide is employed for this purpose in an amount of 1.0 to 1.3 mols per mol of the amide. The process is carried out at 200.degree. to 350.degree. C.

Abstract: A process for the preparation of neopentylamine which is virtually free from amines with a higher degree of alkylation which comprises contacting neopentanol with ammonia at a temperature of 200.degree. to 300.degree. C. in the presence of a hydrogenation catalyst. The process can be carried out under increased pressure and in the presence of catalytic amounts of hydrogen.

Abstract: Optionally substituted fluoro-nitro-benzaldehydes are prepared from optionally substituted halogeno-nitro-benzaldehydes and an alkali metal fluoride in a substantially anhydrous inert aprotic solvent, by heating to 50.degree. to 250.degree. C.

Abstract: Aromatic aminosulphonic acids which have a reduced content of discoloring by-products are obtained when aromatic amines are reacted with a sulphonating agent in a reaction medium at least some of which consists of tetramethylene sulphone.

Abstract: Aminoarylsulphonic acids which have a relatively high purity and a relatively low content of aminoaryldisulphonic acids can be obtained, if they are prepared, from the corresponding arylammonium hydrogen sulphates, by an improved version of the so-called baking process, wherein the reaction is carried out under pressure at a temperature of at least 140.degree. C. and, at least partially, in the presence of water.

Abstract: The process for preparing 1-amino-2-naphthol-4-sulphonic acid by acidifying 3-oxo-4-hydroxyimino-1,2,3,4-tetrahydronaphthalene-1-sulphonic acid or its alkali metal salt in the presence of hydrogen sulphite is carried out in the presence of iron ions.

Abstract: The invention relates to a process for isolating H acid and K acid in the form of their monoalkali metal salts from acid aqueous solutions which contain these two acids and alkali metal ions and may contain other aminonaphtholdisulphonic acids, in which process H acid monoalkali metal salts are precipitated at elevated temperatures from solutions which contain not only sodium ions but also potassium ions and then precipitating K acid monoalkali metal salts by cooling down the filtrate obtained after separating off the H acid monoalkali metal salts.

Abstract: The herbicidal 3,6-substituted 4-amino-1,2,4-triazin-5-one of the general formula ##STR1## wherein R.sup.1 and R.sup.2 have the meaning given in the description,is obtained in good yields by a new two-stage cyclization reaction if an .alpha.-ketocarboxylic acid amide of the general formulaR.sup.1 --CO--CO--NHR.sup.3 (II)is reacted with a hydrazidine of the general formula ##STR2## if appropriate in the presence of a diluent at temperatures between 0.degree. and 150.degree. C., whereby in the first process stage a condensation reaction takes place to give condensation products which still have open chains, and in the second process stage an elimination reaction with ring closure takes place to give the end product of formula (I).

Abstract: Process for the isolation of 1-naphthylamine-4,8-disulphonic acid from sulphonation mixtures containing it according to which process the sulphonation mixture is introduced into preheated water in such a manner that, at the start of crystallization, a temperature of at least 100.degree. C. is reached and the 1-naphthylamine-4,8-disulphonic acid is separated from the mother liquor at a temperature not higher than 70.degree. C. The process is applied particularly advantageously for the isolation of 1-naphthylamine-4,8-disulphonic acid from sulphonation mixtures which have been obtained by introducing in turns alkali metal sulphate, 1-naphthylamine-8-sulphonic acid and SO.sub.3 into sulphuric acid which has been introduced initially, a total of 1.5 to 3 mols of SO.sub.3 and 0.6 to 1.5 mols of alkali metal sulphate being employed per mol of 1-naphthylamine-8-sulphonic acid.

Abstract: 3-Hydroxybenzoic acid is obtained by reaction with an alkali metal hydroxide at a temperature of 220.degree. to 450.degree. C. and under a pressure of 1 to 120 bars, from a technical 3-sulphobenzoic acid mixture which contains sulphuric acid and/or sulphur trioxide and which contains at least 75% by weight of 3-sulphobenzoic acid, relative to the total organic constituents present, and not more than 35% by weight of sulphuric acid and/or SO.sub.3, relative to the total mass. For this purpose, this technical 3-sulphobenzoic acid mixture, if desired after dilution with an equal volume of water, is mixed with sufficient 50 to 100% strength by weight alkali metal hydroxide wherein the remaining 50 to 0% by weight consists essentially of water, for 2.5 to 8 mols of alkali metal hydroxide to be present per mol of 3-sulphobenzoic acid, after neutralization of the sulphuric acid and all the sulpho and carboxyl groups. In general, 10 to 45% by weight of water are present in the batch.

Abstract: In a process for the preparation of 4-nitrotoluene-2-sulphonic acid by reacting 4-nitrotoluene with gaseous sulphur trioxide at an elevated temperature, the improvement wherein molten 4-nitrotoluene is reacted with gaseous sulphur trioxide at a temperature in the range from 60.degree. to 150.degree. C. under a pressure above the vapor pressure of 4-nitrotoluene, in a molar ratio of sulphur trioxide to 4-nitrotoluene of 0.1:1 to 1.5:1, and, after a conversion of at least 70 percent of the reaction component not employed in excess is achieved, the sulphonation mixture is treated with water.

Abstract: Process for the preparation of a bis-(amino-phenyl)-disulphide of the formula ##STR1## in which R represents hydrogen or halogen,which comprises contacting an amino-thiophenol of the formula ##STR2## or a salt thereof in which R has the abovementioned meaningwith sulphur or a sulphur-donating substance in an aqueous dispersion at a temperature of 10.degree. to 120.degree. C. and a pH value of 3 to 9.

Abstract: .alpha.-Ketocarboxylic acid N-acylamides of the formulaR.sup.1 --CO--CO--NH--CO--R.sup.2in whichR.sup.1 is an optionally substituted aliphatic radical with up to 12 carbon atoms, an optionally substituted cycloalkyl radical with 3 to 10 carbon atoms, an optionally substituted heterocyclic radical, andR.sup.2 is an optionally substituted aliphatic radical with up to 8 carbon atoms or an optionally substituted phenyl radical,are prepared by reacting an acyl cyanide of the formulaR.sup.1 --CO--CNwith a carboxylic acid anhydride of the formulaR.sup.2 --CO--O--CO--R.sup.2in the presence of a strong acid, and then adding water to the reaction mixture. The products can be used directly in the synthesis of known herbicides.

Abstract: 3-Nitro-acetoacetanilides of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 independently of one another represent hydrogen, alkyl, cycloalkyl or aryl, it being possible for two of the said radicals to form a cycloaliphatic ring together with the carbon atom on which they are substituents, andR.sup.4 and R.sup.5 independently of one another denote hydrogen, alkyl, aralkyl, aryl, alkoxy, alkylthio, aralkoxy, aralkylthio, aryloxy, arylthio, halogen, nitro or amino disubstituted by alkyl, aralkyl or aryl, andR.sup.4 and R.sup.5, when they are adjacent, can be parts of a fused cycloaliphatic or aromatic ring,are described as well as methods for its preparation such as by reaction of an acetoacetic acid compound with a 3-nitro-aniline under condensation conditions, or, by reaction of an enamine with 3-nitro-phenyl isocyanate. The 3-nitro-acetoacetanilides are useful intermediates in the preparation of coupling components for color photography.

Abstract: A process is provided for the preparation of naphthalene-1,3-5,-trisulphonic acid from 1,5-disulphonated naphthalene, which comprises sulphonating 1,5-disulphonated naphthalene, in the form of a mixture which has been obtained by mixing naphthalene and SO.sub.3 in the presence of an inert solvent at temperatures in the range of -40.degree. to +20.degree. C., the ratio of SO.sub.3 added to naphthalene added having been in the range of 2.5 to 10 mols of SO.sub.3 per mol of naphthalene during the entire addition, at 60.degree. to 110.degree. C. in anhydrous sulphuric acid with oleum, with prior or concurrent separation of the inert solvent.The resulting product is a known intermediate for the formation of azo dyestuffs.

Abstract: In a process for the preparation of an aromatic chloroformic acid ester by contacting a phenol and phosgene, the improvement wherein the reaction is carried out in a homogeneous liquid phase at a temperature of 60.degree. to 180.degree. C. in the presence of organic phosphorus compound of the formulaR.sup.1 R.sup.2 R.sup.3 PR.sup.4.sub.n X.sub.nin whichR.sup.1, R.sup.2 and R.sup.3 independently of one another represent hydrogen, alkyl, alkenyl, aralkyl, aryl or halogen and two of the said radicals together with the phosphorus atom can form a 5-membered or 6-membered phosphorus-containing saturated or unsaturated heterocyclic radical,X represents OH, homopolar-bonded halogen or an inorganic or organic acid anion,R.sup.4 denotes hydrogen or alkyl or, if X denotes halogen, can also denote halogen and n denotes 0 or 1,and in which, furthermore,R.sup.4 and X together can represent oxygen or sulfur.

Abstract: The instant invention is directed to a process for the production of an aromatic isocyanate containing aromatically bound sulfochloride groups, comprising:(I) reacting(a) an isocyanate or carbamic acid chloride which contains at least one aromatically bound isocyanate group and/or at least one aromatically bound carbamic acid chloride group, successively or simultaneously at 0.degree. to 170.degree. C. with(b) a sulfonating agent and(c) an organic compound containing at least one aromatically bound trihalo methyl group and(II) removing hydrogen chloride from the reaction mixture at 20.degree. to 170.degree. C.

Abstract: A process for delignifying lignocellulosic material with a digestion liquor of nitroanthraquinones and/or dinitroanthraquinones. The process can be carried out in a closed reaction vessel at temperatures of 150.degree.-200.degree..+-. C. for 0.5 to 480 minutes with 0.001 to 10% nitroanthraquinone and/or dinitroanthraquinone by weight of lignocellulosic material.

Abstract: A process for the simultaneous preparation of an aromatic sulphonic acid halide and an aromatic carboxylic acid halide or the corresponding carboxylic acid is disclosed wherein an aromatic sulphonic acid or acid anhydride is reacted with an aromatic trihalogenomethyl compound in the presence of a Bronsted acid or Lewis acid at a temperature of 20.degree. to 300.degree. C., if appropriate in the presence of a solvent. Generally, at least half an equivalent of aromatic trihalogenomethyl compound is employed per equivalent of sulphonic acid.