Method for the preparation of trimethylcyclohexyl-alkan-3-ols containing a high proportion of trans isomers
View Patent ↗A method is described for the preparation of a trimethylcyclohexyl-alkan-3-ol containing a proportion of trans isomer of Formula D where R=H, Me, Et, n-propyl, iso-propyl, n-butyl, iso-butyl or tert-butyl and R1=Me, Et, n-propyl, iso-propyl, n-butyl, iso-butyl or tert-butyl, or of a mixture of several such trimethylcyclohexyl-alkan-3-ols, wherein the method comprises catalytically hydrogenating corresponding compound(s) of Formula B in which R and R1 in each case have the indicated meanings, in the presence of a nickel catalyst, preferably of Raney nickel, and in an absence of catalytically active amounts of copper chromite.
1. A method for the preparation of a trimethylcyclohexyl-alkan-3-ol containing a proportion of trans isomer of Formula D
where
R=H, Me, Et, n-propyl, iso-propyl, n-butyl, iso-butyl or tert-butyl and
R1=Me, Et, n-propyl, iso-propyl, n-butyl, iso-butyl or tert-butyl,
or of a mixture of several such trimethylcyclohexyl-alkan-3-ols,
wherein said method comprises catalytically hydrogenating corresponding compounds of Formula B
in which R and R1 in each case have the indicated meanings, in the presence of a base and a nickel catalyst, and in an absence of catalytically active amounts of copper chromite.
2. The method according to claim 1 , wherein said nickel catalyst is a Raney nickel.
3. The method according to claim 1 , wherein process conditions are set such that said trimethylcyclohexyl-alkan-3-ol or said mixture of several such trimethylcyclohexyl-alkan-3-ols contain a proportion of at least 15% trans isomer(s) of Formula C, based on a total amount of trans- and cis isomers prepared.
4. The method according to claim 2 , wherein said Raney nickel is used in an amount of 0.001 to 10% (m/m) based on a mass of said compound(s) of Formula B, in which R and R1 in each case have the indicated meanings.
5. The method according to claim 2 , wherein said Raney nickel is used in an amount of 0.1 to 3% (m/m) based on the mass of said compound(s) of Formula B, in which R and R1 in each case have the indicated meanings.
6. The method according to claim 1 , wherein said base is selected from the group consisting of: hydroxides, oxides, carbonates of alkali metals and carbonates of alkaline earth metals.
7. The method according to claim 1 , wherein said catalytic hydrogenation is carried out at a temperature in a range of between 40 and 350° C.
8. The method according to claim 1 , wherein said catalytic hydrogenation is carried out at a temperature in the range of between 200 and 300° C.
9. The method according to claim 1 , wherein said catalytic hydrogenation is carried out under a pressure in a range of between 1 and 200 bar.
10. The method according to claim 1 , wherein said catalytic hydrogenation is carried out under a pressure in the range of between 10 and 50 bar.
11. A method for the preparation of a perfume composition, with the following steps:
preparation of a trimethylcyclohexyl-alkan-3-ol containing a proportion of trans isomers of Formula D
where
R=H, Me, Et, n-propyl, iso-propyl, n-butyl, iso-butyl or tert-butyl and
R1=Me, Et, n-propyl, iso-propyl, n-butyl, iso-butyl or tert-butyl,
or of a mixture of several such trimethylcyclohexyl-alkan-3-ols, by a method comprising catalytically hydrogenating corresponding compounds of Formula B
in which R and R1 in each case have the indicated meanings, in the presence of a base and a nickel catalyst, and in an absence of catalytically active amounts of copper chromite,
optional isolation and/or purification of said trimethylcyclohexyl-alkan-3-ol or of said mixture,
mixing an aroma changing effect amount of said trimethylcyclohexyl-alkan-3-ol or of said mixture with one or more conventional perfume constituents.