摘要:
A polymer hydrogel substantially free from monomers and oligomers is prepared by contacting a previously prepared polymer hydrogel with a single-phase mixture of water and a solvent and then separating the mixture of water and solvent from the hydrogel.
摘要:
Cyanogen halides and/or phosgene are removed from waste gases by bringing the waste gases into intimate contact with an aqueous solution of at least one amine of the formula NR.sub.3 ; in the formula, 1 or 2 of the radicals R represent an alkanol or alkylamine group having 2 or 3 carbon atoms in each case, where H and/or C.sub.1 -C.sub.2 -alkyl is bound to the nitrogen of the amine group, and the remaining groups R are H or C.sub.1 -C.sub.4 -alkyl.
摘要:
The present invention relates to improved processes for the preparation of 1-amino-2,6-dimethylpiperidine whereby the yield is more than 90%. The processes involve the hydrogenation of 1-nitroso-2,6-dimethylpiperidine in the presence of a palladium catalyst which is partly poisoned with iron ions, in an aqueous solvent, and are characterized by the inclusion of at least one surfactant. The surfactant preferably is anionic or nonionic.
摘要:
The present invention relates to a process for the preparation of benzothioxanthene dyestuffs and cyclisation of 3-(2'-aminophenylthio)-benzanathrones wherein the diazotisation and cyclisation are carried out simultaneously in polar, aprotic solvent in the presence of water.
摘要:
The present invention relates to improved processes for the preparation of 1-amino-2,6-dimethylpiperidine whereby the yield is more than 90%. The processes involve the hydrogenation of 1-nitroso-2,6-dimethylpiperidine in the presence of a palladium catalyst partly poisoned with iron ions but in the substantial absence of water or other solubilizing agents added to the reaction vessel.
摘要:
The present invention relates to a process for the preparation of pyrrole derivatives of the general formula I ##STR1## by reaction of a compound of the general formula III ##STR2## where R, R.sup.1 and R.sup.2 are defined as specified in claim 1, in a Vilsmeier reaction. The reaction is carried out in an easily degradable solvent, the reaction product is isolated with the aid of a water-miscible extractant and is purified by high-vacuum distillation in the short path evaporator.
摘要:
In a process for preparing 2-substituted 1-(acylaminoalkyl)-2-imidazolines of the general formula I ##STR1## where R is an alkylene radical and R.sup.1 is a fatty acid radical, for example a fatty acid and a dialkylenetriamine are reacted with one another in a molar ratio of (1.8 to 2.0):1 by initially introducing one starting material at a temperature T.sub.1 and metering in the second starting material as a liquid, maintaining in the reaction mixture during the addition a temperature T.sub.1 and after the addition until the start of the cyclization a temperature T.sub.2 and distilling off the resulting water or alcohol via a rectification column and, after the acylation product has been formed, cyclizing in a conventional manner, T.sub.1 being a temperature of 170.degree. C. to the boiling point of the initially introduced starting material, but not higher than 250.degree. C., and T.sub.2 being a temperature of 170.degree. to 250.degree. C.