Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
  • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
  • C07F7/02—Silicon compounds
  • C07F7/08—Compounds having one or more C—Si linkages
  • C07F7/18—Compounds having one or more C—Si linkages as well as one or more C—O—Si linkages
  • C07F7/1804—Compounds having Si-O-C linkages

Definitions

• the present invention concerns an improved process for preparing functionalized alkyllithium compounds of the formula (CHs SiORLi, novel trimethylsilyloxy alkyllithium compounds and novel intermediates used in the process.
• U.S. Patent 5,321 ,148, issued June 14, 1994 discloses a process for preparing functionalized alkyllithium compounds by reacting a fine particle size lithium metal of not more than 300 microns average particle size with an organosiloxyalkyl halide of the formula R 1 R 2 R 3 SiORX wherein R 1 , R 2 and R 3 are independently selected from alkyl groups containing 1 to 10 carbon atoms and aryl groups containing 6 to 10 carbon atoms, R is selected from alkyl groups containing 1 to 8 carbon atoms either straight chain or substituted by alkyl or aryl groups, X is selected from chlorine or bromine, the reaction temperature is above 50 °C, the reaction medium is a hydrocarbon solvent and the reaction is conducted in an inert atmosphere.
• organosiloxyalkyl halide of the formula R 1 R 2 R 3 SiORX wherein R 1 , R 2 and R 3 are independently selected from alkyl groups containing 1 to 10 carbon atoms and aryl groups
• R 1 R R SiORX is prepared by reaction of an omega-halo alcohol HORX with R 1 R 2 R 3 SiCI and an acid acceptor, in a hydrocarbon solvent.
• the present invention provides a process for producing compounds of the formula (CHs SiORLi wherein R is selected from alkyl groups containing 2 to 10 carbon atoms and aryl groups containing 6 to 10 carbon atoms, by first reacting a haloalcohol of the formula HORX, wherein R has the meaning ascribed above and X is chlorine or bromine with hexamethyldisuazane, without solvent (neat).
• a trimethylsilyloxy-alkylhalide compound is then reacted, in a second process step, with powdered lithium metal suspended in an inert liquid hydrocarbon solvent to produce the desired trimethylsilyloxyalkyllithium compound.
• the first step of the reaction can be done at temperatures from about 20 °C to 200 °C; the second step of the reaction is done at a temperature that is between 50 ° and 160 °C. Both the first and second step of the process are conducted in an inert atmosphere.
• the first reaction can be catalyzed by a number of catalysts, for example hydrogen chloride, trimethylsilyl chloride, succinimide, saccharin, and barbituric acid.
• the haloalcohol is of the formula HORX , wherein R is selected from alkyl groups of 2 to 10 carbon atoms, straight chain or substituted by alkyl or aryl groups and aryl groups containing 6 to 10 carbon atoms and X is chloro or bromo.
• R is selected from alkyl groups of 2 to 10 carbon atoms, straight chain or substituted by alkyl or aryl groups and aryl groups containing 6 to 10 carbon atoms and X is chloro or bromo.
• the trimethylsilyloxyalkylhalide compounds are produced by reaction of the haloalcohol with hexamethyldisuazane, with no solvent.
• Trimethylsiloxyalkylhalides useful in the practice of this invention include but are not limited to 3-(trimethylsilyloxy)-1-propyl halide, 3-(trimethylsilyloxy)-2- methyl-1-propyl halide, 3-(trimethylsilyloxy)-2,2-dimethyl-1-propyl halide, 4- (trimethylsilyloxy)-l -butyl halide, 5-(trimethylsilyloxy)-1-pentyl halide,6- (trimethylsilyloxy)-l-hexyl halide, 8-(trimethylsilyloxy)-1-octyl halide, and the like.
• the lithium metal is used in particulate or powder form of not greater than 300 micron average particle size and preferably 10 to 300 microns.
• the lithium typically contains 0.4 to 0.76 weight percent sodium and is used in at least stoichiometric amounts, preferably in excess of stoichiometric of 1 to 100% and preferably 20 to 40% excess.
• the lithium dispersion is prepared for use by washing several times with pentane or some other hydrocarbon solvent of choice, to remove the dispersing fluid, and preferably subjected to high speed agitation at elevated temperatures to condition the lithium for the reaction.
• the second process step utilizes a temperature that is from at least 50 °C up to just below the decomposition temperature of the product, and preferably from 50 °C up to the boiling point of the solvent with reflux temperatures being most preferred.
• the optimal temperature for running the reaction can be exceeded by using only a high boiling solvent such as decane (BP-174 °C).
• the useful temperature range for operating the process is between about 50 °C and about 160 °C. Reduced or elevated temperature can be employed if desired but are not required.
• the reactants and the products are not highly corrosive so many materials of construction can be used for the reactor and related process equipment.
• the reaction solvent is an inert, liquid, non-polar hydrocarbon solvent selected from aliphatic, cycloaliphatic and aromatic hydrocarbons or mixtures thereof.
• Preferred solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons, especially alkanes having 3 to 12 carbon atoms, cycloalkanes having 4 to 8 carbon atoms and aromatic hydrocarbons having 6 to 10 carbon atoms and mixtures thereof.
• the inert hydrocarbon medium includes but is not limited to pentane, hexane, cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, heptane, methylcycloheptane, octane, decane, toluene, ethylbenzene, p-xylene, m- xylene, o-xylene, n-propylbenzene, 2-propylbenzene, n-butylbenzene, and t-butylbenzene, and mixtures thereof.
• the precursor triorganosiloxyalkyl halide was prepared neat from the corresponding omega halo-alcohol, and hexamethyldisuazane.
• the lithium metal dispersion when prepared in mineral oil, is washed free of mineral oil with a liquid hydrocarbon solvent, dried in a stream of argon and transferred to the reaction vessel with the hydrocarbon solvent.
• the mixture of clean metal and liquid hydrocarbon solvent was heated to the reaction temperature and the functionalized triorganosiloxyalkyl halide was added slowly to the heated lithium metal-hydrocarbon solvent mixture. An exotherm developed after 5 - 30% of the halide was added.
• the reaction temperature was controlled by external cooling of the reaction mixture.
• the reaction temperature rapidly declined to room temperature.
• the reaction mixture was stirred several hours at room temperature.
• the reaction mixture was transferred to a sintered glass filter through which the solution was filtered rapidly with 3 psi (20.68x10 3 Pa) argon pressure. After the insolubles were removed by filtration, the filtrate was an essentially pure solution of the trimethylsiloxyalkyllithium compound.
• the resultant non-turbid solution was analyzed for total base, active carbon-lithium (modified Watson-Estham titration) and inorganic halide.
• a 500 milliliter, three-necked flask was fitted with a large magnetic stir bar, a reflux condenser, a thermocouple attached to a THERM-O- WATCH®, a 125 ml. pressure-equalizing addition funnel, and an argon inlet.
• This apparatus was dried in an oven overnight at 125 °C, assembled hot, and allowed to cool to room temperature in a stream of argon.
• the flask was charged with 122.58 grams (1.00 mole, 1.00 equivalent) of 3-chloro- 2,2-dimethyl-1-propanol. Hexamethyldisuazane, 83.24 grams (0.516 mole, 0.516 equivalent), was then added rapidly dropwise via the addition funnel.
• Trimethylsilylchloride catalyst one ml., was added via a syringe. An immediate exotherm of 21.7 °C was observed. A white precipitate also formed when the catalyst was added.
• the reaction mixture was heated to 150 °C with a heating mantle, controlled by the THERM-O-WATCH®. After ninety minutes at this temperature, all the solids had dissolved. The heat source was removed.
• the reaction mixture was analyzed by Gas Chromatography (GC), thirty meter X 0.53 mm AT-1 column. All the starting 3-chloro-2,2-dimethyl-1-propanol had been consumed, with the formation of a single, higher-boiling component.
• GC Gas Chromatography
• GC assay 97.5 % desired product, and 2.5 % unknowns.
• a 500 milliliter, three-necked flask was fitted with a large magnetic stir bar, a reflux condenser, a thermocouple attached to a THERM-O- WATCH®, a 125 ml. pressure-equalizing addition funnel, and an argon inlet.
• This apparatus was dried in an oven overnight at 125 °C, assembled hot, and allowed to cool to room temperature in a stream of argon.
• the flask was charged with 122.68 grams (1.00 mole, 1.00 equivalent) of 3-chloro- 2,2-dimethyl-1-propanol. Hexamethyldisuazane, 83.35 grams (0.516 mole, 0.516 equivalent), was then added dropwise via the addition funnel.
• Trimethylsilylchloride catalyst one ml., was added via a syringe. An immediate exotherm of 23.4 °C was observed. A white precipitate also formed when the catalyst was added.
• the reaction mixture was heated to 100 °C with a heating mantle, controlled by the THERM-O-WATCH®. Periodically, an aliquot was removed, filtered through a 0.45 micron syringe filter, and analyzed by Gas Chromatography (GC), thirty meter X 0.53 mm AT-1 column. After twenty-four hours at 100 °C, both of the starting materials were still present. Therefore, an additional 0.5 ml. of trimethylsilylchloride was added.
• GC Gas Chromatography
• GC assay 96.8 % desired product, 0.1 % hexamethyldisuazane, and 3.1 % unknowns.
• a 500 ml., three-necked flask was equipped with a mechanical stirrer, a 125 ml. pressure-equalizing addition funnel, and a Claisen adapter fitted with a dry ice condenser, a thermocouple, and an argon inlet.
• This apparatus was dried in an oven overnight at 125 °C, assembled hot, and allowed to cool to room temperature in a stream of argon.
• Lithium dispersion was washed free of mineral oil with hexane (2 X 70 ml.), and pentane (1 X 70 ml.), then dried in a stream of argon.
• the dry lithium powder 6.80 grams (0.980 mole, 2.80 equivalents) was transferred to the reaction flask with 280 ml. cyclohexane. This slurry was stirred at 450 RPMs, and heated to 64.7 °C with a heating mantle. The heat source was removed. 3-Chloro-2,2-dimethyl-1-trimethylsilyloxy-propane, 68.10 grams (Lot 9277, 0.350 mole, 1.00 equivalent) was then added dropwise to the reaction mixture. An exotherm was noted after 12.3% of the feed had been added. A dry ice/hexane cooling bath was employed to maintain the reaction temperature at 60-65 °C. The total halide feed time was eighty-five minutes.
• Soluble chloride 182 ppm.
• a 500 ml., three-necked flask was equipped with a mechanical stirrer, a 125 ml. pressure-equalizing addition funnel, and a Claisen adapter fitted with a dry ice condenser, a thermocouple, and an argon inlet.
• This apparatus was dried in an oven overnight at 125 °C, assembled hot, and allowed to cool to room temperature in a stream of argon.
• Lithium dispersion was washed free of mineral oil with hexane (2 X 70 ml.), and pentane (1 X 70 ml.), then dried in a stream of argon.
• the dry lithium powder 6.50 grams (0.936 mole, 2.80 equivalents) was transferred to the reaction flask with 280 ml. cyclohexane. This slurry was stirred at 450 RPMs, and heated to 64.7 °C with a heating mantle. The heat source was removed. 3-Chloro-2,2-dimethyl-1-trimethylsilyloxy-propane, 65.09 grams (Lot 9277, 0.334 mole, 1.00 equivalent) was then added dropwise to the reaction mixture. An exotherm was noted after 9.6 % of the feed had been added. A dry ice/hexane cooling bath was employed to maintain the reaction temperature at 60-65 °C. The total halide feed time was ninety- one minutes.
• reaction temperature rapidly fell off at the end of the halide feed.
• the reaction mixture was stirred at room temperature for ninety minutes, then transferred to a small, sintered glass filter.
• the product filtered rapidly with 2 psi argon.
• a one liter, three-necked flask was fitted with a large magnetic stir bar, a reflux condenser, a teflon clad thermocouple, a 125 ml. pressure-equalizing addition funnel, and an argon inlet.
• This apparatus was dried in an oven overnight at 125 °C, assembled hot, and allowed to cool to room temperature in a stream of argon.
• the flask was charged with 122.60 grams (1.00 mole, 1.00 equivalent) of 3-chloro-2,2-dimethyl-1-propanol, and 250 ml. of cyclohexane. This afforded a homogenous solution.
• Hexamethyldisuazane 85.54 grams (0.53 mole, 0.53 equivalent) was then added dropwise. There was an initial endotherm, then the temperature slowly elevated. Total feed time was seventy minutes.
• the catalyst, trimethylsilylchloride (0.5 ml.) was then added with a pipette. A white precipitate formed immediately.
• the reaction flask was swept with a slight positive flow of argon, above the level of the liquid.
• the reaction mixture was heated to reflux with a heating mantle. Ammonia fumes were detected exiting from the apparatus with pH paper before reflux was achieved. After three hours at reflux, the reaction mixture was clear and homogenous. After five and a half hours heating, the heat source was removed.
• the desired product had a boiling point of 169.8 - 175.0 °C.
• the comparison example shows the superiority of performing the trimethylsilation reaction without solvent.
• the neat reaction featured faster reaction rates, easier work-up, and no need for extensive product purification by distillation.

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• 1994
  • 1994-07-25 US US08/279,721 patent/US5403946A/en not_active Expired - Lifetime
  • 1994-11-21 US US08/341,822 patent/US5543540A/en not_active Expired - Lifetime
• 1995
  • 1995-07-24 EP EP95927358A patent/EP0800525B1/en not_active Expired - Lifetime
  • 1995-07-24 JP JP8505889A patent/JPH10504813A/ja active Pending
  • 1995-07-24 WO PCT/US1995/009256 patent/WO1996003408A1/en not_active Ceased
  • 1995-07-24 AU AU31410/95A patent/AU3141095A/en not_active Abandoned
  • 1995-07-24 DE DE69530322T patent/DE69530322T2/de not_active Expired - Fee Related

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