摘要:
2(5H)-furanones I ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, C.sub.1 -C.sub.6 -alkyl, C.sub.5 - or C.sub.6 -cycloalkyl, C.sub.7 -C.sub.12 -aralkyl or aryl, are prepared by heating a 3-formylcarboxylate or 3-formylcarboxylic acid II ##STR2## where R.sup.3 is hydrogen, C.sub.1 -C.sub.12 -alkyl, C.sub.5 - or C.sub.6 -cycloalkyl, C.sub.7 -C.sub.12 -aralkyl or aryl, to 100.degree.-450.degree. C. in the presence of an acidic catalyst.
摘要:
In an improved process for the preparation of 6-aminocaproates by reacting a 5-formylvalerate with ammonia and hydrogen using an alkanol as a solvent in the presence of a hydrogenation catalyst at elevated temperatures and under superatmospheric pressure, the improvement comprises carrying out the reaction at from 40.degree. to 95.degree. C.
摘要:
A process for the preparation of aliphatic, cycloaliphatic, arylaliphatic and aliphatic-cycloaliphatic di- and polyurethanes wherein primary aliphatic, cycloaliphatic, arylaliphatic or aliphatic-cycloaliphatic di- or polyamines are reacted with urea and a primary or secondary aliphatic alcohol at temperatures of above 190.degree. C. to 300.degree. C., following which ammonia and other by-products are separated from the aliphatic, cycloaliphatic, arylaliphatic or aliphatic-cycloaliphatic di- or polyurethane product.
摘要:
2-Methylalk-2-enals of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl or an aromatic radical, are prepared by isomerization of an acrolein derivative of the formula ##STR2## with a zeolite catalyst, an aluminum silicate and/or an aluminum phosphate.
摘要:
A process for the preparation of an aliphatic, cyclo-aliphatic, and/or aliphatic-cycloaliphatic di- and/or polyurethane comprising the steps ofA. reacting a primary aliphatic, cycloaliphatic, and/or aliphatic-cycloaliphatic di- and/or polyamine with a carbamate in the presence of alcohol at temperatures of 160.degree. C. to 300.degree. C., andB. separating the ammonia and other by-products from the aliphatic, cycloaliphatic, and/or aliphatic-cycloaliphatic di- and/or polyurethane.One or more catalysts may be added to the reactants to increase the reaction rate. The aliphatic, cycloaliphatic, and/or aliphatic-cycloaliphatic 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:
1-Alkenyl isocyanates are prepared by reacting aldehydes with carbamates to give N-(1-alkenyl)-carbamates and splitting these compounds at elevated temperatures. The 1,2-unsaturated isocyanates obtained are valuable starting materials for the preparation of pest control agents, dyes, drugs, textile water repellents, detergents, plastics, bleaches and adhesives, since they possess an activated double bond or an activated .alpha.-carbon atom, in addition to a reactive isocyanate group.
摘要:
.alpha.-Alkylacroleins are prepared by reacting an alkanal with formaldehyde and a secondary amine in the presence of a carboxylic, dicarboxylic or polycarboxylic acid in certain molar ratios within a pH range of from 2.5 to 7 and at from 0.degree. to 150.degree. C.The .alpha.-alkylacroleins which can be prepared by the process described are valuable starting materials for dyes, drugs and pest control agents.
摘要:
Hydrogenation catalysts which are prepared from mixed crystals of copper-zinc compounds, obtained by precipitation, of the formulaCu.sub.1.5-3 Zn.sub.1-2.5 (CO.sub.3).sub.1-2 (OH).sub.4-6.(H.sub.2 O).sub.0-1by decomposition at 200.degree.-500.degree. C., and are used for the catalytic preparation of propanediols of the formula ##STR1## where the R's may be identical or different and each is an aliphatic, araliphatic or aromatic radical, or the two R's together with the adjacent carbon atom are members of an alicyclic ring, by hydrogenating hydroxypropionaldehydes of the formula ##STR2## where R has the above meanings, and to processes for the preparation of propanediols, using such catalysts. The propane-1,3-diols obtainable by the novel process are valuable starting materials for the preparation of lubricants, plastics, surface coatings and synthetic resins, for example of polyesters derived from the propanediols.
摘要:
Hydrogenation catalysts, which have a specific surface area of from 50 to 150 square meters per gram, solely or partially contain crystals having a spinel structure and copper in the form of copper oxide, and have been obtained by precipitating copper and aluminum in a ratio of from 0.25 to 3 atoms of copper per atom of aluminum from their compounds in the presence of a carbonate at a pH of from 4.5 to 9 and calcining the resulting precipitate at from 300.degree. to 800.degree. C., for the catalytic preparation of propanediols by hydrogenating hydroxypropionaldehydes at not more than 300 bar pressure and from 50.degree. to 200.degree. C., and processes for the preparation of propanediols by the use of such catalysts.The propanediols obtainable by the process of the invention, in particular 2,2-dimethylpropane-1,3-diol, are valuable starting materials for the preparation of lubricants, plastics, surface coatings and synthetic resins, for example corresponding polyesters.