Process for preparing 4-cyclohexyl-2-methyl-2-butanol

Abstract

The present invention relates to a process for preparing 4-cyclohexyl-2-methyl-2-butanol. The process comprises the following steps: a) reaction of styrene with isopropanol at elevated temperature to obtain 4-phenyl-2-methyl-2-butanol, and b) heterogeneously catalyzed hydrogenation of 4-phenyl-2-methyl-2-butanol over a catalyst suitable for ring hydrogenation of aromatics.

1 - 35 . (canceled) 
     
     
         36 . 4-Cyclohexyl-2-methyl-2-pentanol. 
     
     
         37 . A process for preparing 4-cyclohexyl-2-methyl-2-pentanol, comprising the heterogeneously catalyzed hydrogenation of 2-methyl-4-phenyl-2-pentanol over a catalyst suitable for ring hydrogenation of aromatics. 
     
     
         38 . The process according to  claim 37 , comprising
 a′) preparing a composition comprising 2-methyl-4-phenyl-2-butanol and 2-methyl-4-phenyl-2-pentanol by reaction of styrene with isopropanol at elevated temperature under conditions under which isopropanol is present under supercritical conditions, the molar ratio of styrene to isopropanol being in the range from 1:10 to 1:130;   b′) heterogeneously catalyzed hydrogenation of the composition obtained in step a′) over a catalyst suitable for ring hydrogenation of aromatics; and   c) distillative workup of the composition obtained in step b′) to obtain a composition consisting essentially of 4-cyclohexyl-2-methyl-2-pentanol;   or   c′) distillative workup of the composition obtained in step a′) to obtain a composition consisting predominantly of 2-methyl-4-phenyl-2-pentanol and   b′) heterogeneously catalyzed hydrogenation of the composition obtained in step c) over a catalyst suitable for ring hydrogenation of aromatics; and optionally   c″) distillative workup of the composition obtained in step b′) to obtain a composition consisting essentially of 4-cyclohexyl-2-methyl-2-pentanol.   
     
     
         39 . The process according to  claim 37 , comprising:
 a″) reacting α-methylstyrene with isopropanol at elevated temperature to obtain 2-methyl-4-phenyl-2-pentanol, and   b″) heterogeneously catalyzed hydrogenation of 2-methyl-4-phenyl-2-pentanol over a catalyst suitable for ring hydrogenation of aromatics.   
     
     
         40 . A composition comprising 4-cyclohexyl-2-methyl-2-pentanol. 
     
     
         41 . The composition as claimed in  claim 40 , which additionally comprises 4-cyclohexyl-2-methyl-2-butanol. 
     
     
         42 . The composition according to  claim 41 , in which the weight ratio of 4-cyclohexyl-2-methyl-2-butanol to 4-cyclohexyl-2-methyl-2-pentanol is in the range from 50:1 to 1000:1. 
     
     
         43 . A fragrance which comprises the composition according to  claim 40 . 
     
     
         44 . A cosmetic composition which comprises the composition according to  claim 40 . 
     
     
         45 . A washing or cleaning composition which comprises the composition according to  claim 40 . 
     
     
         46 . A fragrance which comprises the 4-cyclohexyl-2-methyl-2-pentanol according to  claim 36 . 
     
     
         47 . A cosmetic composition which comprises the 4-cyclohexyl-2-methyl-2-pentanol according to  claim 36 . 
     
     
         48 . A washing or cleaning composition which comprises the 4-cyclohexyl-2-methyl-2-pentanol according to  claim 36 . 
     
     
         49 . The process according to  claim 37 , wherein essentially no feedstocks other than styrene and isopropanol are used for reaction in step a′). 
     
     
         50 . The process according to  claim 37 , wherein the reaction in step a′) is effected at a temperature in the range from 250 to 500° C. and a pressure in the range from 5 to 50 MPa. 
     
     
         51 . The process according to  claim 37 , wherein at least 80% of the isopropanol is initially charged and at least 80% of the styrene used in step a′) is fed to the reaction in step a′) under reaction conditions. 
     
     
         52 . The process according to  claim 38 , wherein essentially no feedstocks other than α-methylstyrene and isopropanol are used for reaction in step a″). 
     
     
         53 . The process according to  claim 38 , wherein the reaction in step a″) is effected at a temperature in the range from 250 to 500° C. and a pressure in the range from 5 to 50 MPa. 
     
     
         54 . The process according to  claim 38 , wherein at least 80% of the isopropanol is initially charged and at least 80% of the styrene used in step a″) is fed to the reaction in step a″) under reaction conditions. 
     
     
         55 . The process according  claim 36 , wherein the catalyst suitable for ring hydrogenation of aromatics is a supported catalyst, which comprises, as an active metal, ruthenium, rhodium or nickel alone or together with at least one further active metal of transition groups IB, VIIB or VIIIB of the Periodic Table of the Elements (CAS version) on a support material selected from silicon dioxide-containing and aluminum oxide-containing support materials. 
     
     
         56 . The process according to  claim 36 , wherein the catalyst suitable for ring hydrogenation of aromatics is a supported catalyst, which comprises, as an active metal, ruthenium alone or together with at least one further active metal of transition groups IB, VIIB or VIIIB of the Periodic Table of the Elements (CAS version) on a support material selected from silicon dioxide-containing and aluminum oxide-containing support materials.