摘要:
A process for the preparation of an aryl mono-, di-, and/or polyurethane comprising the steps of A. reacting a primary aromatic mono-, di-, and/or polyamine with an O-alkyl carbamate in the presence of an alcohol at temperatures greater than 160.degree. C., andB. separating the ammonia and other by-products from the aryl mono-, di-, and/or polyurethane.The reaction is preferably carried out in the presence of urea. The aryl mono-, di-, and/or polyurethanes produced are valuable end and intermediate products. They can be transferred into the corresponding isocyanates which can then be used for the preparation of polyurethanes.
摘要:
N-Aryloxazolidine-2,4-diones are prepared by reacting a nitrobenzene with a 2-hydroxycarboxylic acid ester and carbon monoxide in the presence of selenium and a basic compound under super-atmospheric pressure and at an elevated temperature.The N-aryloxazolidine-2,4-diones of the formula I, obtainable by the process of the invention are valuable active ingredients and starting materials for the preparation of crop protection agents, dyes and drugs.
摘要:
A process for the preparation of an aryl-mono and/or polyurethane comprising the steps ofA. reacting a primary aromatic mono, di-, and/or polyamine with an O-alkyl carbamate in the presence of alcohol and catalysts, andB. separating the ammonia and other by-products from the aliphatic and/or cycloaliphatic di- and/or polyurethane.The reaction is preferably carried out in the presence of urea. The aryl mono-, di-, and/or polyurethanes produced are valuable end and intermediate products. They can be transferred into the corresponding isocyanates which can then be used for the preparation of polyurethanes.
摘要:
A method for regulating the viscosity of aqueous detergent and cleanser slurries, in which there are added to the slurries, as viscosity regulators, dihydric, trihydric or tetrahydric aliphatic alcohols, monobasic aliphatic carboxylic acids, hydroxycarboxylic acids, esters of the said alcohols and the said acids or mixtures of these, in which compounds the alcohols, carboxylic acids and hydroxycarboxylic acids, and the individual components of the esters, are of 5 to 9 carbon atoms, of which one is a quaternary atom, the alcohols and hydroxycarboxylic acids carry exclusively primary alcohol groups, and the carboxylic acids and hydroxycarboxylic acids have the carboxyl group bonded to the quaternary carbon atom.
摘要:
Phenol ethers are prepared by reacting phenols with dialkyl carbonates in the presence of tertiary amines and/or phosphines. The aralkyl aryl ethers and alkyl aryl ethers obtained are starting materials for the manufacture of dyes, crop protection agents and scents.
摘要:
The preparation of 2-substituted but-2-ene-1,4-dial-4-acetals of the formula I ##STR1## in which the substituents R.sup.1 to R.sup.4 stand for hydrogen or C.sub.1 -C.sub.6 aliphatic radicals, and R.sup.2 and R.sup.3 or R.sup.1 and R.sup.2 are in each case common members of an aliphatic 4-membered to 7-membered ring, which can contain a hetero atom, and R.sup.5 denotes an alkyl, alkenyl, or alkynyl radical having from 1 to 12 C atoms, which can be substituted by cycloaliphatic, aromatic or heterocyclic radicals or by hydroxy, ether, thioether, acyl, alkylamino, carboxy, or carbalkoxy groups, an optionally substituted aryl radical or an alkoxy, alkylthio, or acyloxy group, whereina) glyoxal is caused to react with a 1,3-propanediol of the formula II ##STR2## in aqueous solution in the presence of an acid to form a monoacetal of the formula III ##STR3## is neutralized, and if necessary the components more readily volatile than the monoacetal III are distilled off,b) the monoacetal III obtained is caused to react with an aldehyde R.sup.5 CH.sub.2 --CHO in the presence of from 0.01 to 10 mol %, based on glyoxal, of a catalyst mixture of a secondary amine and an acid to form an aldol of the formula IV ##STR4## the components which are more volatile than the aldol IV being distilled off if necessary, andc) the aldol IV is dehydrated in the presence of a water-eliminating agent to form the product I,and novel hemiacetals of glyoxal monoacetals.
摘要:
A process for the preparation of 3-cyano-3,5,5-trimethylcyclohexanone by the reaction of isophorone with hydrogen cyanide in the presence of quaternary ammonium catalysts at temperatures ranging from 80.degree. to 180.degree. C. and pressures ranging from 0.5 to 20 bar, in which the ammonium catalysts used are salts of the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4 denote C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.18 aralkyl or C.sub.2 -C.sub.18 hydroxyalkyl andX denotes HCO.sub.3 or ##STR2## with the proviso that R.sup.4 stands for C.sub.1 -C.sub.8 alkyl when X is ##STR3##
摘要:
A multistep process for the continuous preparation of organic polyisocyanates, preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to give monomeric polyurethanes and pyrolyzing the latter involves separating the resultant polyisocyanates and worthless residues in certain reaction steps and recycling the reusable by-products into earlier steps.
摘要:
A process for preparing neopentyl glycol hydroxypivalate by base-catalyzed disproportionation of hydroxypivalaldehyde, wherein the reaction is carried out in the presence of a readily water-soluble alkaline earth metal salt and of an alkali metal hydroxide.
摘要:
A process for the preparation of 2,2-bis-hydroxymethyl-butanediol-(1,4) of formula I ##STR1## wherein 4-hydroxybutyraldehyde of formula II ##STR2## and/or 2-hydroxytetrahydrofuran of formula III ##STR3## is/are condensed with formaldehyde in the presence of a basic catalyst and the resulting reaction mixture is then catalytically hydrogenated, and 2,2-bis-hydroxymethyl-butanediol-(1,4) is isolated from the hydrogenation product.