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

Abstract

A process for preparing 4-cyclohexyl-2-methyl-2-butanol, comprising: a) reaction of styrene with isopropanol at elevated temperature to obtain 2-methyl-4-phenyl-2-butanol, and b) heterogeneously catalyzed hydrogenation of 2-methyl-4-phenyl-2-butanol over a catalyst suitable for ring hydrogenation of aromatics, where the molar ratio of the styrene used in step a) to the isopropanol used in step a) is in the range from 1:below 5 to 1:0.5.

1 - 24 . (canceled) 
     
     
         25 . A process for preparing a composition comprising 2-methyl-4-phenyl-2-butanol and 2-methyl-4-phenyl-2-pentanol comprising the 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:below 10 to 1:0.5. 
     
     
         26 . The process according to  claim 25 , wherein at least 80% of the isopropanol is initially charged and at least 80% of the styrene used is supplied to the reaction under reaction conditions. 
     
     
         27 . The process according to  claim 25 , wherein the elevated temperature is above 300° C. 
     
     
         28 . The process according to  claim 25 , wherein the elevated temperature is above 320° C. 
     
     
         29 . The process according to  claim 25 , wherein the elevated temperature is 390° C. to 500° C. 
     
     
         30 . The process as claimed in  claim 25 , wherein the molar ratio of the styrene used in step a) to the isopropanol used in step a) is in the range from 1:4.9 to 1:0.5. 
     
     
         31 . The process as claimed in  claim 25 , wherein the molar ratio of the styrene used in step a) to the isopropanol used in step a) is in the range from 1:4.5 to 1:0.5. 
     
     
         32 . The process as claimed in  claim 25 , wherein the molar ratio of the styrene used in step a) to the isopropanol used in step a) is in the range from 1:4 to 1:0.75. 
     
     
         33 . The process as claimed in  claim 25 , wherein the molar ratio of the styrene used in step a) to the isopropanol used in step a) is in the range from 1:3.5 to 1:1.15. 
     
     
         34 . The process as claimed in  claim 25 , wherein the molar ratio of the styrene used in step a) to the isopropanol used in step a) is in the range from 1:2 to 1:1. 
     
     
         35 . A process for preparing 4-cyclohexyl-2-methyl-2-pentanol comprising
 a′) preparation of 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:below 10 to 1:0.5;   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.   
     
     
         36 . The process as claimed in  claim 35 , wherein the molar ratio of the styrene used in step a′) to the isopropanol used in step a′) is in the range from 1:4.5 to 1:0.5. 
     
     
         37 . The process as claimed in  claim 35 , wherein the molar ratio of the styrene used in step a′) to the isopropanol used in step a′) is in the range from 1:4 to 1:0.75. 
     
     
         38 . The process as claimed in  claim 35 , wherein the molar ratio of the styrene used in step a′) to the isopropanol used in step a′) is in the range from 1:3.5 to 1:1.15. 
     
     
         39 . The process as claimed in  claim 35 , wherein the molar ratio of the styrene used in step a′) to the isopropanol used in step a′) is in the range from 1:2 to 1:1. 
     
     
         40 . A process for preparing 4-cyclohexyl-2-methyl-2-pentanol comprising
 a″) reaction of 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,
 where the molar ratio of the α-methylstyrene used in step a″) to the isopropanol used in step a″) is in the range from 1:below 5 to 1:0.5. 
   
     
     
         41 . The process as claimed in  claim 40 , wherein the molar ratio of the styrene used in step a″) to the isopropanol used in step a″) is in the range from 1:4.5 to 1:0.5. 
     
     
         42 . The process as claimed in  claim 40 , wherein the molar ratio of the styrene used in step a″) to the isopropanol used in step a″) is in the range from 1:4 to 1:0.75. 
     
     
         43 . The process as claimed in  claim 40 , wherein the molar ratio of the styrene used in step a) to the isopropanol used in step a″) is in the range from 1:3.5 to 1:1.15. 
     
     
         44 . The process as claimed in  claim 35 , wherein the molar ratio of the styrene used in step a″) to the isopropanol used in step a″) is in the range from 1:2 to 1:1.