Patent GB-446576-A (GB)
Title: Process of producing rotenone and associated substances from natural sources containing the same
IPC: A01N65/20
Filed: 1934-10-29
Abstract: Rotenone or preparations having insecticidal value containing it are produced by subjecting the natural substances containing rotenone to distillation at raised temperature in a high vacuum and collecting the distillate.  The process is preferably effected by short-path high-vacuum evaporative distillation, i.e. distillation without ebullition at 10<-2> to 10<-6> mms. pressure, with the evaporating and condensing surfaces substantially co-extensive and in close proximity.  The natural source itself may be directly distilled in the finely ground solid state, or may be introduced into the distillation apparatus in admixture with a substance which is liquid at the operating temperature, which may be a solvent for the active substances in which case insoluble matter may first be separated by filtration or otherwise.  The liquid used is usually one which is nonvolatile at the operating temperature, e.g. a linseed oil stand oil, unbodied triglyceride oils such as cotton-seed or olive oil, previously freed from free fatty acids, or mineral oil fractions previously treated in a high vacuum to remove volatile constituents, such as those known under the Registered Trade Mark "Apiezon."  The condensate from the distillation may be removed from the condensing surface by melting down, scraping, or rinsing with a solvent.  In some cases a volatile or partially volatile carrier liquid, e.g. a mixture of "Apiezon A" and "Apiezon K," may be used, yielding a solution or mixture applicable directly as an insecticide, if desired after further dilution, e.g. with mineral oils or fractions thereof, such as kerosene.  The product is a mixture of the rotenone and associated substances of insecticidal activity, which may be employed as an insecticide without further purification, or from which practically pure rotenone may be separated by fractional distillation.  In examples: (1) dry ground derris root is mixed with a linseed oil stand oil and the mixture is fed on to a surface heated to about 120 DEG  C. in close proximity to a cold condensing surface, and distilled under about 10<-4> mms. pressure; (2) finely ground derris root is distilled at 150--160 DEG  C. and 10<-3> mms. pressure in an apparatus of the type in which the evaporating and condensing surfaces comprise thin flexible metal bands, the effective portions lying in horizontal planes with the evaporating surface below the condensing surface, adapted to move in close proximity to heating and cooling bodies respectively; (3) powdered derris root is heated with "Apiezon K," and the mixture is filtered hot, fed on to the evaporating surface of a short-path highvacuum still, and distilled at 165 DEG  C. and 10<-4> mms. pressure.  In the examples, the derris root may be replaced by powdered cub<\>e root.  Specification 437,895 is referred to.ALSO:Rotenone or preparations having insecticidal value containing it are produced by subjecting the natural substances containing rotenone to distillation at raised temperature in a high vacuum and collecting the distillate.  The process is preferably effected by short-path high-vacuum evaporative distillation, i.e. distillation without ebullition at 10<-2> to 10<-6> mms. pressure, with the evaporating and condensing surfaces substantially co-extensive and in close proximity.  The natural source itself may be directly distilled in the finely ground solid state, or may be introduced into the distillation apparatus in admixture with a substance which is liquid at the operating temperature, and may be a solvent for the active substances in which case insoluble matter may first be separated by filtration or otherwise.  The liquid used is usually one which is non-volatile at the operating temperature, e.g. a linseed oil stand oil, unbodied triglyceride oils such as cotton-seed or olive oil, previously freed from free fatty acids, or mineral oil fractions previously treated in a high vacuum to remove volatile constituents, such as those known under the Registered Trade Mark "Apiezon."  The condensate from the distillation may be removed from the condensing surface by melting down, scraping, or rinsing with a solvent.  In some cases a volatile or partially volatile carrier liquid, e.g. a mixture of "Apiezon A" and "Apiezon K," may be used, yielding a solution or mixture applicable directly as an insecticide, if desired after further dilution, e.g. with mineral oils or fractions thereof, such as kerosene.  The product is a mixture of the rotenone and associated substances of insecticidal activity, which may be employed as an insecticide without further purification, or from which practically pure rotenone may be separated by fractional distillation.  In examples: (1) dry ground derris root is mixed with a linseed oil stand oil and the mixture is fed on to a surface heated to about 120 DEG  C. in close proximity to a cold condensing surface, and distilled under about 10<-4> mms. pressure; (2) finely ground derris root is distilled at 150--160 DEG C. and 10<-3> mms. pressure in an apparatus of the type in which the evaporating and condensing surfaces comprise thin flexible metal bands, the effective portions lying in horizontal planes with the evaporating surface below the condensing surface, adapted to move in close proximity to heating and cooling bodies respectively; (3) powdered derris root is heated with "Apiezon K," and the mixture is filtered hot, fed on to the evaporating surface of a short-path high-vacuum still, and distilled at 165 DEG  C. and 10<-4> mms. pressure.  In the examples the derris root may be replaced by powdered cub<\>ae root.  Specification 437,895 is referred to.ALSO:Rotenone or preparations having insecticidal value containing it are produced by subjecting the natural substances containing rotenone to distillation at raised temperature in a high vacuum and collecting the distillate.  The process is preferably effected by short-path high-vacuum evaporative distillation, i.e. distillation without ebullition at 10-2 to 10-6 mms. pressure, with the evaporating and condensing surfaces substantially co-extensive and in close proximity.  The natural source itself may be directly distilled in the finely ground solid state, or may be introduced into the distillation apparatus in admixture with a substance which is liquid at the operating temperature, which may be a solvent for the active substances, in which case insoluble matter may first be separated by filtration or otherwise.  The liquid used is usually one which is non-volatile at the operating temperature, e.g. a linseed oil stand oil, unbodied triglyceride oils such as cotton-seed or olive oil, previously freed from free fatty acids, or mineral oil fractions previously treated in a high vacuum to remove volatile constituents, such as those known under the Registered Trade Mark "Apiezon."  The condensate from the distillation may be removed from the condensing surface by melting down, scraping, or rinsing with a solvent.  In some cases a volatile or partially volatile carrier liquid, e.g. a mixture of "Apiezon A" and "Apiezon K," may be used, yielding a solution or mixture applicable directly as an insecticide, if desired after further dilution, e.g. with mineral oils or fractions thereof, such as kerosene.  The product is a mixture of the rotenone and associated substances of insecticidal activity, which may be employed as an insecticide without further purification, or from which practically pure rotenone may be separated by fractional distillation.  In examples: (1) dry ground derris root is mixed with a linseed oil stand oil and the mixture is fed on to a surface heated to about 120 DEG  C. in close proximity to a cold condensing surface, and distilled under about 10-4 mms. pressure; (2) finely ground derris root is distilled at 150-160 DEG  C. and 10-3 mms. pressure in an apparatus of the type in which the evaporating and condensing surfaces comprise thin flexible metal bands, the effective portions lying in horizontal planes with the evaporating surface below the condensing surface, adapted to move in close proximity to heating and cooling bodies respectively; (3) powdered derris root is heated with "Apiezon K," and the mixture is filtered hot, fed on to the evaporating surface of a short-path high-vacuum still, and distilled at 165 DEG  C. and 10-4 mms. pressure.  In the examples the derris root may be replaced by powdered cub<\>ae root.  Specification 437,895 is referred to.