Patent GB-404643-A (GB)
Title: Improvements in the preparation of ketones
IPC: C07C45/29
Filed: 1932-04-16
Abstract: Ketones are manufactured by heating secondary alcohols, e.g cyclic terpene secondary alcohols, to an elevated temperature under superatmospheric pressure, in the liquid phase, with an unsaturated hydrocarbon, e.g. a cyclic compound, in the presence of a hydrogenation catalyst, the temperature and pressure conditions being such that the unsaturated hydrocarbon is hydrogenated, and the proportion of unsaturated hydrocarbon present being not less than that theoretically required for complete reaction with all the hydrogen eliminated from the alcohol, e.g. at least one third molecular proportion of an aromatic hydrocarbon to one molecular proportion of secondary alcohol.  Suitable reaction conditions are pressures of 100--300 lbs. per sq. in. and temperatures of 175--250 DEG  C.  The hydrocarbon employed should preferably be such that its hydrogenation product has a boiling point or boiling range considerably above or below the boiling point of the ketone formed, in order to facilitate separation.  Where the alcohol used has a high boiling point the hydrocarbon should preferably have a low boiling point to insure the formation of the requisite pressure.  In examples: (1) to (3) borneol or isoborneol and benzene in various proportions are heated to 200 DEG  C. in an autoclave in the presence of a hydrogenation catalyst, e.g. nickel, to produce camphor and hydrogenated benzene; instead of nickel there may be used nickel oxide or a nickel carbonate-copper carbonate mixture, the mass being, if desired, first reduced with hydrogen under pressure; the amount of catalyst may be 1--10 per cent, preferably 2--6 per cent by weight of the amount of secondary alcohol; (4) fenchyl alcohol and benzene are heated to 225 DEG  C. in an autoclave in the presence of a reduced nickel carbonate-copper carbonate catalyst, producing fenchone and hydrogenated benzene; (5) in a similar manner, isopropyl alcohol and naphthalene yield acetone, whilst cyclohexanol and benzene, naphthalene or dipentene yield cyclohexanone and hydrogenated benzene, tetrahydronaphthalene or menthane respectively.  Other hydrocarbons specified are toluene and abietene.ALSO:Ketones are manufactured by heating secondary alcohols, e.g cyclic terpene secondary alcohols, to an elevated temperature under super-atmospheric pressure, in the liquid phase, with an unsaturated hydrocarbon, e.g. a cyclic compound, in the presence of a hydrogenation catalyst, the temperature and pressure p  conditions being such that the unsaturated hydrocarbon is hydrogenated, and the proportion of unsaturated hydrocarbon present being not less than that theoretically required for complete reaction with all the hydrogen eliminated from the alcohol, e.g. at least one-third molecular proportion of an aromatic hydrocarbon to one molecular proportion of secondary alcohol.  Suitable reaction conditions are pressures of 100--300 lbs. per sq. in. and temperatures of 175--250 DEG  C.  The hydrocarbon employed should preferably be such that its hydrogenation product has a boiling point or boiling range considerably above or below the boiling point of the ketone formed, in order to facilitate separation.  Where the alcohol used has a high boiling point the hydrocarbon should preferably have a low boiling point to insure the formation of the requisite pressure.  In examples: (1) to (3) borneol or isoborneol and benzene in various proportions are heated to 200 DEG  C. in an autoclave in the presence of a hydrogenation catalyst, e.g. nickel, to produce camphor and hydrogenated benzene; instead of nickel there may be used nickel oxide or a nickel carbonate-copper carbonate mixture, the mass being, if desired, first reduced with hydrogen under pressure; the amount of catalyst may be 1--10 per cent, preferably 2--6 per cent by weight of the amount of secondary alcohol; (4) fenchyl alcohol and benzene are heated to 225 DEG  C. in an autoclave in the presence of a reduced nickel carbonate-copper carbonate catalyst, producing fenchone and hydrogenated benzene; (5) in a similar manner, isopropyl alcohol and naphthalene yield acetone, whilst cyclohexanol and benzene, naphthalene or dipentene yield cyclohexanone and hydrogenated benzene, tetrahydronaphthalene or menthane respectively.  Other hydrocarbons specified are toluene and abietene.