摘要:
Aminomethylene compounds of the formula ##STR1## can be prepared by reaction of C-H-acid compounds of the formula ##STR2## with salts of the formula ##STR3## in the presence of simple inorganic bases, where the radicals R.sup.1 to R.sup.4, R.sup.7, R.sup.8 and X.sup..crclbar. have the meanings given in the description.
摘要:
Thermotropic, fully aromatic polyesters based on p-hydroxybenzoic acid, aromatic dicarboxylic acid and diphenol in which the dicarboxylic acid groups consist at least in part of 3,3'-diphenyldicarboxylic acid groups have excellent mechanical properties, in particular excellent elongation at break.
摘要:
1-Amino-naphthalene-7-sulphonic acid is prepared by reacting 1-chloro-naphthalene-4,7-disulphonic acid with ammonia at elevated temperatures in the presence of water and optionally in the presence of a catalyst such as a copper catalyst.
摘要:
p-Amino-phenols are advantageously prepared by catalytic hydrogenation of the aromatic nitro compounds on which they are based in a reaction medium of aqueous sulphuric acid in the sense of a Bamberger rearrangement at elevated temperature by a procedure in which the reaction medium additionally contains a water-miscible organic solvent.
摘要:
Pure or substantially enriched 2,4- and 2,6-dinitrotoluene can be isolated from a mixture containing these isomers if such a mixture is distilled under a pressure of 0.5 to 20 mbar at a temperature of 80.degree. to 200.degree. C. with exclusion of reducing conditions.
摘要:
Process for the preparation of alkyl aryl ethers containing carboxyl groups which are suitable for the preparation of colour film couplers, or derivatives thereof, by reaction of aromatic alcohols with alkyl halides containing carboxyl groups or derivatives thereof and basic alkali metal or alkaline earth metal compounds, characterized in that the reaction is carried out in the melt of the aromatic alcohol.
摘要:
Mononitrohalogenobenzenes can be prepared by mixing halogenobenzene, nitric acid, sulphuric acid and water intensively with one another, simultaneously or in succession in their total quantity, and by redispersing them at least twice in the case of continuous preparation, applying a mixing energy of 1-40 watts per liter of the overall reaction mixture, preferably 3-30 W/l, largely suppressing back-mixing in the continuous procedure, and observing adiabatic reaction conditions.
摘要:
Mononitrotoluenes can be prepared by intensively mixing together toluene, nitric acid, sulphuric acid and water, simultaneously or successively in their total amount, and, in the case of continuous preparation, redispersing the mixture at least twice, for which purpose a mixing energy of 1 to 40 watts per liter of the total reaction mixture, preferably 3 to 30 W/l, is employed per volume of the reactor, and, for the continuous procedure, the back mixing is substantially repressed. Adiabatic reaction conditions are maintained.
摘要:
Crude 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)propane (=tetramethyl-bisphenol A=TMBPA) can be purified by recrystallization, if C.sub.1 -C.sub.4 -monoalcohols with a water content of 2 to 40% by weight relative to the total weight of alcohol and water are used in an amount of 70 to 250% by weight, relative to the amount of TMBPA and the recrystallization is carried out at a temperature of 65.degree. to 150.degree. C.
摘要:
1,5- AND 1,8-DINITRONAPHTHALENES ARE ISOLATED FROM MIXTURES OF ISOMETRIC DINITRONAPHTHALENES AT LEAST CONTAINING THE SAME. The mixture of isomers is treated successively with a more polar solvent and a less polar aromatic solvent for dinitronaphthalenes thereby dissolving the mixture of isomers except for 1,5-dinitronaphthalenes which remains largely undissolved in the more polar solvent. The residual mixture of isomers is subsequently treated, after removal of the more polar solvent, with a less polar aromatic solvent at elevated temperatures in which 1,8-dinitronaphthalenes remains as a largely insoluble residue.