Abstract: The present invention relates to a process for purifying a composition (I) at least comprising cyclododecanone. The process according to the invention for purifying a composition (I) at least comprising cyclododecanone comprises at least step (i) (i) irradiation of the composition (I).

Abstract: The present application relates to a process for reacting a composition I comprising at least one aldehyde with hydrogen in the presence of a catalyst in at least one main reactor and at least one postreactor, wherein at least 50% of the fresh hydrogen fed to the reaction system is fed into at least one postreactor. In a preferred embodiment, composition I comprises at least one further organic compound.

Abstract: A process for working up by distillation the crude products obtained in the process according to DE-A 196 07 954 and containing 1,6-hexanediol (HDO), 1,5-pentanediol (PDO) or caprolactone (CLO) in order to obtain the corresponding pure products, the working-up by distillation being carried out in each case in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper common column region (1), a lower common column region (6), a feed section (2, 4) having a rectification section (2) and stripping section (4), and a take-off section (3, 5) having a stripping section (3) and rectification section (5), with feeding of the respective crude product HDO, PLO or CLO in the middle region of the feed section (2, 4) and removal of the high boiler fraction (C) from the bottom of the column, of the low boiler fraction (A) via the top of the column and of the medium boiler fraction (B) from the middle region of the take-off section (3, 5), or

Abstract: The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.

Abstract: In a dividing wall column comprising as segments a) an upper column region (6), b) an inflow section (7), c) an offtake section (8) and d) a lower column region (9), the inflow section b) (7) and the offtake section c) (8) are separated from one another laterally by a dividing wall (10) fixed in the column and the dividing wall (10) is located between the upper column region a) (6) and the lower column region d) (9). The present invention provides for the dividing wall (10) to be constructed at least partly of an elastic material, the dividing wall (10) to have a slightly overdimensional width and the dividing wall (10) to be fixed in the column by the dividing wall exercising an elastic recovery force on the interior wall of the column. The dividing wall can easily be installed in, in particular, relatively small columns.

Abstract: A process for preparing at least one unsaturated alcohol (B) comprises the steps (I) to (III) below: (I) reaction of at least one alkali metal hydroxide or alkaline earth metal hydroxide with at least one alcohol (A) in at least one organic solvent (L) to give a mixture (G-I) comprising at least the alcohol (A), the solvent (L) and an alkoxide (AL); (II) reaction of at least one carbonyl compound of the formula R—CO—R? with at least one alkyne of the formula R?—C?C—H and the mixture (G-I) obtained in step (I) to give a mixture (G-II) comprising at least the alcohol (A), the solvent (L) and an unsaturated alcohol (B); (III) distillation of the mixture (G-II) obtained in step (II) to give the alcohol or alcohols (B) and a mixture (G-III) comprising the solvent (L) and the alcohol (A), wherein the solvent (L) obtained in step (III) and the alcohol (A) obtained in step (III) are recycled as a mixture to step (I).

Abstract: A process for preparing cyclohexanol from benzene by: a) preparing cyclohexene by hydrogenating benzene in the presence of a catalyst, and b) preparing cyclohexanol by hydrating the cyclohexene in the presence of a catalyst, comprises: carrying out steps a) and b) in a reaction facility which has a bottom region at the lower end, a top region at the upper end, and a reaction zone between the top region and the bottom region which contains the catalyst according to steps a) and b), evaporating a portion of the benzene using the heat of reaction in the reaction zone, condensing it in the top region and returning it to the reaction zone, and withdrawing a reaction mixture containing cyclohexanol in the bottom region.

Abstract: A process for preparing cyclohexanol from benzene by a) preparing cyclohexene by hydrogenating benzene in the presence of a catalyst and b) preparing cyclohexanol by hydrating the cyclohexene in the presence of a catalyst, comprises carrying out steps a) and b) in a reaction facility which has a bottom region at the lower end, a top region at the upper end and a reaction zone between the top region and the bottom region which contains the catalyst according to steps a) and b), evaporating a portion of the benzene using the heat of reaction in the reaction zone, condensing it in the top region and returning it to the reaction zone, and withdrawing a reaction mixture containing cyclohexanol in the bottom region.

Abstract: The present invention relates to a process for preparing 5-alkoxy-substituted oxazoles, in particular for preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.

Abstract: The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.

Abstract: A process for preparing 1,6-hexanediol from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol after water extraction of the reaction mixture followed by extraction with aqueous sodium hydroxide solution, by esterification of the acids and hydrogenation comprises a) liberating the carboxylic acids from the alkaline extract by addition of a mineral acid, b) fractionating the organic phase comprising carboxylic acids to give a distillate comprising the low molecular weight monocarboxylic acids and a residue comprising adipic acid and 6-hydroxycaproic acid, c) reacting the monocarboxylic an dicarboxylic acids present in the aqueous dicarboxylic acid mixture with a low molecular weight alcohol to give the corresponding carboxylic esters, d) freeing the esterification mixture obtained of excess alcohol and low boilers in a first distillation step, e) frac

Abstract: The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.

Abstract: A process for working up by distillation the crude products obtained in the process according to DE-A 196 07 954 and containing 1,6-hexanediol (HDO), 1,5-pentanediol (PDO) or caprolactone (CLO) in order to obtain the corresponding pure products, the working-up by distillation being carried out in each case in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper common column region (1), a lower common column region (6), a feed section (2, 4) having a rectification section (2) and stripping section (4), and a take-off section (3, 5) having a stripping section (3) and rectification section (5), with feeding of the respective crude product HDO, PLO or CLO in the middle region of the feed section (2, 4) and removal of the high boiler fraction (C) from the bottom of the column, of the low boiler fraction (A) via the top of the column and of the medium boiler fraction (B) from the middle region of the take-off section (3, 5), or

Abstract: A process is disclosed for the purification, by distillation, of trimethylolpropane originating from the hydrogenation of 2,2-dimethylolbutanal, said process including the following steps: (a) reaction of n-butyraldehyde with formaldehyde in the presence of catalytic amounts of a tertiary amine, and hydrogenation of the resulting mixture to give a mixture containing trimethylolpropane; (b) separation of water, methanol, trialkylamine and/or trialkylammonium formate by distillation; (c) heating of the residue obtained in (b) under reduced pressure to a temperature at which TMP is volatile and compounds boiling above TMP are cleaved, in order to separate off, by distillation, TMP and compounds more volatile than TMP; (d) distillation of the distillate obtained in (c) in order to separate off the more volatile compounds and recover pure TMP; and (e) optional distillation of the TMP obtained in (d) in order to recover TMP with a low APHA color index.

Abstract: The present invention relates to a process for preparing 5-alkoxy-substituted oxazoles, in particular for preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.

Abstract: The present invention relates to a process for continuously preparing 5-alkoxy-substituted oxazoles, in particular for continuously preparing 4-methyl-5-alkoxy-substituted oxazoles and also a process for preparing pyridoxine derivatives.

Abstract: The present invention relates to a process for the continuous preparation of 5-alkoxy-substituted oxazoles, in particular for the continuous preparation of 4-methyl-5-alkoxy-substituted oxazoles, and to a process for preparing pyridoxine derivatives.

Abstract: A process for the preparation of 5-alkoxy-substituted oxazoles, in particular for the preparation of 4-methyl-5-alkoxy-substituted oxazoles, and a process for the preparation of pyridoxine derivatives are described.

Abstract: A process is disclosed for the purification, by distillation, of trimethylolpropane originating from the hydrogenation of 2,2-dimethylolbutanal, said process comprising the following steps:

Abstract: A process for preparing 1,3-diols having 6 or more carbon atoms comprises a) provision of at least one alkanal having at least three carbon atoms; b) thermal treatment of the alkanal in the absence of a basic catalyst; c) hydrogenation of the aldol addition product formed in step b); and d) isolation of the 1,3-diol obtained. The process of the present invention makes it possible to prepare 1,3-diols simply and inexpensively.