摘要:
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).
摘要:
A process for preparing a ketone, in particular cyclododecanone, by reacting cyclododecatriene with dinitrogen monoxide to obtain cyclododecadienone and hydrogenating the resulting cyclododecadienone, in particular to give cyclododecanone.
摘要:
The present invention provides a process for preparing 1,6-hexanediol by hydrogenating dialkyl adipates, alkyl 6-hydroxycaproates, 1,4-cyclohexanedione and 4-hydroxycyclohexan-1-one as ester mixtures comprising impurities, by a) freeing resulting the esterification mixture of excess alcohol and low boilers in a first distillation stage (alcohol removal), b) carrying out a separation of the bottom product in a second distillation stage into an ester fraction substantially free of 1,4-cyclohexanediols and a fraction comprising at least the majority of the 1,4-cyclohexanediols, c) catalytically hydrogenating the ester fraction substantially free of 1,4-cyclohexanediols (ester hydrogenation) and d) in a purifying distillation stage, obtaining 1,6-hexanediol from the hydrogenation effluent in a manner known per se, which comprises selectively hydrogenating the ester mixture before stage a) and/or before stage b) (purifying hydrogenation).
摘要:
A process is described for preparing diaminodiarylmethanes comprising the steps a) reacting an aromatic amine with a methylene-donating agent in the presence of homogeneous acid catalysts, b) removing the homogeneous acid catalyst from the reaction product, c) working up and purifying the reaction product, which comprises removing the homogeneous acid catalyst from the reaction mixture by adsorption to a solid adsorbent.
摘要:
In a process for preparing alcohols by catalytic hydrogenation of carbonyl compounds over a catalyst comprising rhenium on activated carbon, the catalyst used comprises rhenium (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5, platinum (calculated as metal) in a weight ratio to the activated carbon of from 0.0001 to 0.5 and, if appropriate, at least one further metal selected from among Zn, Cu, Ag, Au, Ni, Fe, Ru, Mn, Cr, Mo, W and V in a weight ratio to the activated carbon of from 0 to 0.25, and the activated carbon has been nonoxidatively pretreated It is also possible to prepare ethers and lactones if the hydrogen pressure is not more than 25 bar. In this case, the activated carbon in the catalyst may also have been nonoxidatively pretreated.
摘要:
A continuous process for the preparation of O—, S— and N-alkenyl compounds by reaction of the corresponding OH, SH or NH compound with an acetylene in the liquid phase in the presence of basic alkali or alkaline earth metal compounds at from 40 to 300° C. and from 0.11 to 5 MPa absolute comprises continuously feeding the corresponding OH, SH or NH compound and the acetylene and operating at a conversion of the corresponding OH, SH or NH compound of ≧90%.
摘要:
A process for preparing N-alkenyl-amides by reacting the corresponding NH-amides with acetylenes in the liquid phase in the presence of basic alkali metal compounds and of a cocatalyst comprises using as the cocatalyst compounds of the general formulae (Ia) and/or (Ib) R1O—(CH2CH2CH2CH2O)n—H (Ia): R1O—(CH2CH2CH2CH2O)n—R2, (Ib): where n is 1, 2 or 3 and R1 and R2 are independently C1- to C6-alkyl or C2- to C6-alkenyl, or together a butenyl unit.
摘要:
A process for purifying alkenyl compounds having a divalent or trivalent heteroatom in the &agr;-position relative to the double bond by distillation comprises carrying out at least two distillations in which the purified alkenyl compounds are obtained from the gas phase by condensation, where the time between the first distillation after the synthesis of the alkenyl compounds and at least one further distillation is at least one day and the purified alkenyl compounds have an APHA color number of
摘要:
A dialdehyde, trialdehyde or tetraldehyde or at least two thereof as aldehyde are hydrogenated by bringing into contact at least: the aldehyde; a catalyst comprising at least one metal selected from the group consisting of nickel, cobalt and copper in chemically bound and/or elemental form; hydrogen; at a gas pressure in the range from 5 to 350 bar and a temperature in the range from 40 to 300° C.