Abstract: The invention provides an improvement in terms of control and process technology for a method of continuous removal of a component from a liquid mixture using a membrane unit comprising at least one membrane stage. The improvement is that a portion of the overall permeate stream is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device, and the remainder of the overall permeate stream is removed, with the recycled permeate having a higher concentration of the component to be separated off than the removed permeate. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

Abstract: The invention provides an improvement in terms of control and process technology for a method of continuous removal of a component from a liquid mixture using a membrane unit comprising at least one membrane stage. The improvement is that a portion of the overall permeate stream is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device, and the remainder of the overall permeate stream is removed, with the recycled permeate having a higher concentration of the component to be separated off than the removed permeate. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

Abstract: The invention provides an improvement in terms of control and process technology for a method of continuous removal of a component from a liquid mixture using a membrane unit comprising at least one membrane stage. The improvement is that at least some of the overall permeate stream obtained is recycled to the feed vessel and/or beyond the feed vessel but upstream of the conveying device. The presently disclosed method can especially be used for separation of a homogeneously dissolved catalyst from a liquid reaction mixture.

Abstract: A heat exchanger system can be used for removal or introduction of heat from or into a chemical reactor in which a chemical reaction is proceeding. The system further provides an apparatus for controlling the temperature of a reactor and a process for performing a chemical reaction, in each case using a heat exchanger system with a thermally insulated inner tube.

Abstract: A heat exchanger system can be used for removal or introduction of heat from or into a chemical reactor in which a chemical reaction is proceeding. The system further provides an apparatus for controlling the temperature of a reactor and a process for performing a chemical reaction, in each case using a heat exchanger system with a thermally insulated inner tube.

Abstract: The present invention relates to a method for coupling two arenes with selenium dioxide to give a selenobiaryl ether. The method of the present invention includes: adding a first arene to the reaction mixture, adding a second arene to the reaction mixture, adding selenium dioxide to the reaction mixture, adding an acid having a pKa in the range from 0 to 5 to the reaction mixture, and adjusting the reaction temperature of the reaction mixture such that the first arene and the second arene are converted to a selenobiaryl ether. The present invention also relates to novel selenobiaryl ethers.

Abstract: A process for preparing unsymmetric biphenols, comprising: a) adding a first substituted phenol to the reaction mixture; b) adding a second substituted phenol having different substitution than the first phenol to the reaction mixture; c) adding selenium dioxide to the reaction mixture; d) adding a solvent; and e) heating the reaction mixture such that the first substituted phenol and the second phenol having different substitution are converted to an unsymmetric biphenol.

Abstract: Method for coupling a phenol and an arene using selenium dioxide, and also novel phenol-arene derivatives.

Abstract: The present invention concerns a method for producing asymmetrical biphenols using selenium dioxide.

Abstract: A process for preparing a 2,2?-biphenol, proceeds by a) adding a first phenol to a reaction mixture, b) adding a second phenol to the reaction mixture, c) adding selenium dioxide to the reaction mixture, d) adding an acid having a pKa in the range from 0.0 to 5.0 to the reaction mixture, and e) heating the reaction mixture such that the first phenol and the second phenol are converted to said 2,2?-biphenol.

Abstract: Method for coupling two arenes with selenium dioxide to give a selenobiaryl ether, and also novel selenobiaryl ethers.

Abstract: Method for coupling a phenol and an arene using selenium dioxide, and also novel phenol-arene derivatives.

Abstract: The invention is concerned with a process for preparing 2,2?-biaryls, especially of 2,2?-biphenols in which a reaction mixture comprising a first aryl, a second aryl and selenium dioxide is heated, the first aryl being reacted with the second aryl to give the corresponding 2,2?-biaryl, wherein the reaction mixture additionally comprises molybdenum(V) chloride.

Abstract: A process for preparing a 2,2?-selenobiaryl ether or a 4,4?-selenobiaryl ether, proceeds by a) adding a first phenol to the reaction mixture, b) adding a second phenol to the reaction mixture, c) adding selenium dioxide to the reaction mixture, d) adding a base having a pKb in the range from 8 to 11 to the reaction mixture, and e) adjusting the reaction temperature of the reaction mixture such that the first phenol and the second phenol are converted to said 2,2?-selenobiaryl ether or said 4,4?-selenobiaryl ether.

Abstract: A process for preparing a 2,2?-biphenol, proceeds by a) adding a first phenol to a reaction mixture, b) adding a second phenol to the reaction mixture, c) adding selenium dioxide to the reaction mixture, d) adding an acid having a pKa in the range from 0.0 to 5.0 to the reaction mixture, and e) heating the reaction mixture such that the first phenol and the second phenol are converted to said 2,2?-biphenol.

Abstract: 2,2?-biphenol is prepared in a process using selenium dioxide and a halogenated solvent.