Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
  • C07C29/32—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring increasing the number of carbon atoms by reactions without formation of -OH groups
  • C07C29/34—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring increasing the number of carbon atoms by reactions without formation of -OH groups by condensation involving hydroxy groups or the mineral ester groups derived therefrom, e.g. Guerbet reaction

Definitions

• the invention relates to a method for producing
• Guerbet alcohols by condensation of at least one primary or secondary alkanol having 2 to 30 carbon atoms and having a methylene group in the alpha position to the carbon atom bearing the hydroxyl group in the presence of an alkaline catalyst and a cocatalyst at elevated temperature and with removal of the water of reaction, if appropriate using a water-immiscible entrainer.
• Guerbet alcohols are formed in the condensation of primary and secondary alcohols in the presence of alkali according to the reaction scheme
• Alkali metals alkali metal hydroxides, alkali metal oxides or alkali metal alcoholates, together with palladium salts as cocatalysts.
• the main reaction takes place according to the formula scheme above, but in addition, depending on the catalyst, higher molecular alcohols are also formed, namely by further reaction of a Guerbet alcohol formed from two alkanol molecules with one or more further alkanol molecules.
• the raw condensation product must be fractionally distilled
• the cocatalyst is a derivative of titanium (IV) or zirconium (IV) acid, selected from that of alkali metal titanates, alkali metal zirconates, esters of titanium (IV) or zirconium (IV) -acid with C 1 -C 4 -alkanols or with polyols with 2 to 12 carbon atoms and 2 to 6 hydroxyl groups,
• Titanium dioxide zirconium dioxide, mixed anhydrides
• alkanols having 2 to 30 carbon atoms and having one Methylene group in the alpha position to the carbon atom carrying the hydroxyl group can be converted to the desired Guerbet alcohols, which are essentially free of higher molecular weight condensation products.
• Alkanols of this type can be represented by the general formula I
• R 1 -CH (R 2 ) -CH 2 -OH (I) can be reproduced.
• the radicals R 1 and R 2 which may be the same or different, are hydrogen, aryl or straight-chain or branched alkyl.
• Typical examples of such alkanols are ethanol, propanol, isopropanol, butanol, pentanol,
• the aforementioned starting compounds can be of synthetic origin, e.g. so-called Ziegler or oxo alcohols; however, they can also be of natural origin. In this
• connections of particularly preferred starting compounds are straight-chain primary alkanols having 6 to 22 carbon atoms, such as those derived from fats and oils of vegetable or animal origin
• Myristyl, cetyl, stearyl, arachidyl and behenyl alcohol Myristyl, cetyl, stearyl, arachidyl and behenyl alcohol.
• Suitable alkaline catalysts for the process of the invention are oxides, hydroxides and alcoholates (from C 1 -C 4 alkanols) of alkali metals such as lithium, sodium, potassium and cesium; Potassium hydroxide and / or cesium hydroxide are particularly preferred.
• Titanium or zirconium compounds of the general formula II are Titanium or zirconium compounds of the general formula II
• M tetravalent titanium or zirconium and R 3 is an alkyl group with at least 2, in particular 2 to 4 carbon atoms, an acyl group with 2 to 14 carbon atoms or a residue of a beta-diketone of the general formula III
• R 4 and R 5 are identical or different radicals from the group formed by alkyl groups with 1 to 4 carbon atoms and optionally substituted in the p-position phenyl, two of the groups R 3 together from the
• divalent radical of a dihydric alkanol having 2 to 4 carbon atoms can be formed
• Titanium (IV) or zirconium (IV) acetylacetonate Condensation products of titanium (IV) or zirconium (IV) tetraalkoxylates of the general formula II, in which M and R 2 are as defined above, with polyfunctional ones
• Alkanols in particular with 2 to 12 carbon atoms and 2 to 6 hydroxyl groups.
• Zirconium compounds are known and the majority are commercially available. Condensation products of titanium (IV) or zirconium (IV) tetraalkoxylates with polyfunctional alkanols with 2 to 12 carbon atoms and 2 to 6 hydroxyl groups such as
• Glycerin, trimethylolpropane and pentaerythritol are examples of Glycerin, trimethylolpropane and pentaerythritol.
• Esterification and / or transesterification catalysts e.g. in US-C 4,705,764, the contents of which are incorporated herein by reference.
• a suitable polyalkanol is also polyvinyl alcohol.
• Titanic acid H 4 TiO 4
• zirconic acid H 4 ZrO 4
• mixed anhydrides of titanium or zirconic acid with organic acids of general formula II, in which M Ti or Zr and R 3 is an alkyl group with 1 to 4 carbon atoms or an acyl group derived from a monocarboxylic acid with 2 to 4
• Titanium or zirconium acetylacetonates of the general formula (IV) can also be used
• R 6 is an alkyl group with 1 to 4 carbon atoms
• ACA is an acetylacetonate radical
• m is the number 0 and n is the number 4 or m is the number 2 and n is the number 2
• inorganic or organic zinc compounds in particular zinc oxide and zinc acetate, can be used as additional
• cocatalysts in an amount of 0.1 to 1 wt .-%, based on primary or secondary alkanol.
• the condensation is preferably carried out at temperatures from 200 to 260 ° C., if appropriate under pressure; working under pressure is particularly necessary in the case of starting alkanols which have an excessively high vapor pressure at the reaction temperatures.
• Particularly suitable entraining agents which can be used in the process of the invention are toluene, xylene and 1-ethylhexanol, which form azeotropes with water.
• the method of the invention is preferred based on
• Distillation head with water separator 633 g (4 mol) of an approximately 99.9% n-decanol were placed in and slowly heated after addition of the catalyst.
• the potassium hydroxide used was added in the form of a 50% potassium hydroxide solution. After distilling off the water originating from the potassium hydroxide solution at approx. 120 to 150 ° C, the distillation of the water originating from the Guerbet reaction began at approx. 230 ° C. From this point in time, the reaction time was measured and the amount of water formed was used as a measure of the course of the reaction; the reaction was stopped when the water separation practically reached
• the catalyst / cocatalyst systems used and their amounts (in mmol / 100 g) of the starting product, the reaction time (in min), the water of reaction formed (in% by weight, based on the theoretically expected amount), the composition of the reaction product (in% by weight).
• % Starting compound and% by weight of C 20 condensation product the degree of conversion (U; in% by weight), the selectivity (S; in% by weight) and the yield (A; in
• Example catalyst nMol / reaction water.

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• 1989
  • 1989-01-16 DE DE3901095A patent/DE3901095A1/de not_active Withdrawn
• 1990
  • 1990-01-08 WO PCT/EP1990/000028 patent/WO1990008122A1/de not_active Application Discontinuation
  • 1990-01-08 BR BR909007035A patent/BR9007035A/pt not_active Application Discontinuation
  • 1990-01-08 EP EP90902202A patent/EP0454742A1/de not_active Withdrawn
  • 1990-01-08 JP JP2502567A patent/JPH04502764A/ja active Pending

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