Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C33/00—Unsaturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
  • C07C33/40—Halogenated unsaturated alcohols
  • C07C33/42—Halogenated unsaturated alcohols acyclic
  • C07C33/423—Halogenated unsaturated alcohols acyclic containing only double bonds as unsaturation
• • 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
  • C07C29/58—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by elimination of halogen, e.g. by hydrogenolysis, splitting-off
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/58—Preparation of carboxylic acid halides

Definitions

• the present invention relates to new alcohols which are the 3,3-dihalo-2-fluoro-1-propenols-1 which can be used as precursors of 2-fluoro-acrylic acid or of a halide of this acid for the preparation of fluoro -2 acrylates.
• Fluoro-2 acrylates are of great industrial interest because their polymers or copolymers are used in the composition of many materials such as paints, varnishes, dental resins and special windshields.
• the fluoro-2 acrylates can be obtained by conventional methods from fluoro-2-acrylic acid or a halide of 2-fluoro acrylic acid. there is also known a method for preparing fluoro-acrylates which uses 2-fluoro acrolein as a precursor compound.
• Fluoro-2 acrolein can be prepared by condensation of dichlorofluoromethane with n-butylvinyl ether, as described by H. MOLINES et al. in "Synthesis” (1985) pages 754 to 756.
• a halide of 2-fluoro acrylic acid for example the fluoride of 2-fluoro acrylic acid, can be prepared from tetrafluoro-2,2,3,3-oxetane by ring opening, as described in European patent EP-A-0 136 668.
• the methods described in this European patent have the drawback of being relatively difficult to implement since they require a certain number of steps to arrive at the halides of 2-fluoro acrylic acid.
• the present invention specifically relates to new 3,3-dihalo-fluoro-2-propenols-1 which make it possible to prepare the halides of 2-fluoro acrylic acid of a much simpler way.
• the 3,3-dihalo-fluoro-2-propenols-1 correspond to the formula:
• X 1 and X 2 which may be identical or different, represent a fluorine, chlorine or bromine atom provided that X 1 and X do not both have a chlorine atom.
• X 1 and X 2 represents fluorine and the other can represent chlorine or bromine.
• At least one of X 1 and X 2 represents chlorine and neither of the two X 1 and X 2 represents fluorine.
• X 1 and X 2 which may be the same or different, represent a fluorine, chlorine or bromine atom, can be easily prepared from the corresponding halogenated saturated alcohols.
• X 1 and X 2 which may be the same or different, represent a fluorine, chlorine or bromine atom, can be easily prepared from the corresponding halogenated saturated alcohols.
• organometallic compound of formula R 1 Li in which R 1 is an alkyl radical, preferably from 1 to 4 carbon atoms, and the 3,3-dihalo-fluoro-2-propenol-1 of formula (I) thus obtained is separated from the reaction medium.
• This reaction is generally carried out at a temperature of 0 to 40 ° C, in an anhydrous organic solvent such as ether.
• the organolithium compound can in particular be methyllithium.
• R 1 Li organolithium compound
• the alcohols of formula (II) used as starting material for this reaction are commercial compounds or compounds which are easy to prepare by conventional methods, for example by radical condensation of methanol on halogenated olefins, as described by JD La Zerte in JACS (1955), vol.77, p.910.
• the alcohols of formula (I) of the invention can be converted into halides of 2-fluoro acrylic acid in a single step.
• the subject of the invention is also a process for preparing a halide of 2-fluoro acrylic acid of formula:
• X is a fluorine, chlorine or bromine atom, characterized in that an acid 3,3-2-fluoro-1-propenol-dihalogen of formula:
• X 1 and X 2 which may be the same or different, represent a fluorine, chlorine or bromine atom, to obtain by allylic transposition the 2-fluoro acrylic acid halide of formula
• This reaction is carried out in an acid medium such as sulfuric acid, in solution in an organic solvent, for example in methylene chloride or tetrachloroethane.
• an acid medium such as sulfuric acid
• organic solvent for example in methylene chloride or tetrachloroethane.
• the acid halide is generally distilled directly from the reaction medium under a slight vacuum and it is trapped in a cold bath.
• X 1 and X 2 are fluorine. If we want to obtain an acid chloride, X 1 is chlorine and X 2 is chlorine or bromine. When we want to obtain acid bromide, X 1 and X 2 are bromine.
• the acid halides of formula (III) can be used for the preparation of 2-fluoro acrylic acid or its derivatives, in particular esters.
• the subject of the invention is also a process for preparing 2-fluoro acrylic acid or its esters of formula:
• R 2 represents a hydrogen atom, an alkyl radical of 1 to 10 carbon atoms or an aryl radical, which comprises the following steps: a) - preparing a 3,3-dihalo-2-fluoro-propenol-1 of formula :
• X 1 X 2 C CF-CH 2 OH (I) in which X 1 and X 2 which may be identical or different, represent a fluorine, chlorine or bromine atom, by treatment of an alcohol of formula:
• the compounds of formula (I) of the invention can also be used for the preparation of 3,3-dihalo-2-fluoro-acrylic acids of formula:
• X 1 and X 2 which may be the same or different, represent a fluorine, chlorine or bromine atom.
• the halogen X 4 used to form the tet raha logeno fluoro-2 propanol is chosen so as to be more easily eliminated than the halogens X 1 and X 2 of the compound of formula (I).
• X 4 can be chlorine, bromine or iodine.
• X 4 can be chlorine, bromine or iodine.
• X 4 can be bromine or iodine.
• the following oxidation reaction can be carried out using specific oxidation reagents for allyl alcohols, such as MnO 2 , CrO 3 - pyridine, CrO 3 -H 2 SO 4 .
• specific oxidation reagents for allyl alcohols such as MnO 2 , CrO 3 - pyridine, CrO 3 -H 2 SO 4 .
• the reaction is carried out with a reducing metal such as zinc.
• a reducing metal such as zinc.
• the polymers of the compounds of formula (V) or their esters can also find interesting uses as resistant functional membranes.
• X 1 and X 2 which may be the same or different, represent a fluorine, chlorine or bromine atom and R 3 is an alkyl or aryl radical. They can be prepared by an analogous process comprising the following successive steps: a) - preparing a 3,3-dihalo-fluoro-2-propenol-1 of formula:
• X 1 and X 2 have the meaning given above and X 3 is a fluorine, chlorine or bromine atom, identical or different from X 1 and / or X 2 , by an organometallic compound of formula R 1 L i in which R 1 is an alkyl radical, preferably from 1 to 4 carbon atoms, and by separation of the reaction medium from 3,3-dihalo-2-fluoro-propenol-1 of formula (I) thus obtained, b) - halogenating the 3,3-dihalo-fluoro-2 propenol-1 of formula (I) thus obtained by a halogen X 4 2 to form a tet raha logeno fluoro-2 propanol of formula:
• the aryl radicals which can be used for R 2 and R 3 are for example the phenyl, biphenyl, naphthyl, anthracenyl unsubstituted or substituted by one or more substituents such as halogen atoms, alkyl and ether radicals.
• the compounds of formula (I) of the invention are therefore very advantageous compounds because they allow access, under mild conditions and by methods comprising few steps, to the 2-fluoro acrylates used for the preparation of polymers and copolymers with significant industrial interest.
• the following examples are of course given without implied limitation to illustrate the invention.
• CF 2 CF-CH 2 OH (compound No. 1)
• Example 2 The procedure is as in Example 1 by introducing 137 mmol of CH 3 Li into a solution of 10 g (68.4 mmol) of alcohol HCFCICF 2 CH 2 OH in 10 ml of anhydrous ether. After five hours, the medium is neutralized with concentrated hydrochloric acid (approximately 17 ml) after adding 50 ml of salt water. The organic phase is decanted, washed and dried over magnesium sulfate. When the ether is removed, the reaction product is distilled under a partial vacuum Eb: 90-95 ° C (17 kPa, 125 Torr).
• Example 3 The distillate obtained in Example 3 is diluted in 10 ml of CH 2 Cl 2 . 1.2 g (12.7 mmol) of phenol are added thereto and the mixture is left overnight at room temperature.
• the mixture is stirred for one hour, then drawn under a slight vacuum (20.2 kPa, 150 Torr) to distill until dry.
• the distillate is rectified in the presence of hydroqui none.

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• Oil, Petroleum & Natural Gas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1988
  • 1988-05-27 FR FR8807086A patent/FR2631960A1/fr not_active Withdrawn
• 1989
  • 1989-05-26 EP EP89906381A patent/EP0374233A1/de not_active Withdrawn
  • 1989-05-26 JP JP1506158A patent/JPH04500952A/ja active Pending
  • 1989-05-26 WO PCT/FR1989/000254 patent/WO1989011470A1/fr not_active Ceased

Non-Patent Citations (1)

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