Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J31/00—Catalysts comprising hydrides, coordination complexes or organic compounds
  • B01J31/02—Catalysts comprising hydrides, coordination complexes or organic compounds containing organic compounds or metal hydrides
  • B01J31/0234—Nitrogen-, phosphorus-, arsenic- or antimony-containing compounds
  • B01J31/0235—Nitrogen containing compounds
  • B01J31/0239—Quaternary ammonium compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
  • B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
  • B01J19/122—Incoherent waves
  • B01J19/126—Microwaves
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01D—COMPOUNDS OF ALKALI METALS, i.e. LITHIUM, SODIUM, POTASSIUM, RUBIDIUM, CAESIUM, OR FRANCIUM
  • C01D3/00—Halides of sodium, potassium or alkali metals in general
  • C01D3/02—Fluorides
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
  • C07B39/00—Halogenation
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C17/00—Preparation of halogenated hydrocarbons
  • C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
  • C07C17/20—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms
  • C07C17/202—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms two or more compounds being involved in the reaction
  • C07C17/208—Preparation of halogenated hydrocarbons by replacement by halogens of halogen atoms by other halogen atoms two or more compounds being involved in the reaction the other compound being MX
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
  • C07C201/06—Preparation of nitro compounds
  • C07C201/12—Preparation of nitro compounds by reactions not involving the formation of nitro groups
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2231/00—Catalytic reactions performed with catalysts classified in B01J31/00
  • B01J2231/005—General concepts, e.g. reviews, relating to methods of using catalyst systems, the concept being defined by a common method or theory, e.g. microwave heating or multiple stereoselectivity
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2231/00—Catalytic reactions performed with catalysts classified in B01J31/00
  • B01J2231/40—Substitution reactions at carbon centres, e.g. C-C or C-X, i.e. carbon-hetero atom, cross-coupling, C-H activation or ring-opening reactions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2531/00—Additional information regarding catalytic systems classified in B01J31/00
  • B01J2531/90—Catalytic systems characterized by the solvent or solvent system used
  • B01J2531/98—Phase-transfer catalysis in a mixed solvent system containing at least 2 immiscible solvents or solvent phases

Definitions

• the subject of the present invention is a process for the actinic activation of mineral fluorides in an organic medium. It relates more particularly to the exchanges between fluorine and halogen of higher rank.
• the fluorine ion is involved in many reactions in organic chemistry.
• the sources of fluorine ions are either very expensive or particularly difficult to implement due to the low reactivity of the alkali or alkaline earth salts of hydrofluoric acid.
• alkali or alkaline earth fluorides are very little or little soluble in the usual organic media.
• these fluorides are generally hygroscopic while their action is profoundly modified or altered by the presence of water.
• the reactions involving alkali fluorides and a fortiori alkaline - earths remain particularly lazy and require a high reaction time which considerably reduces the productivity of installations using such fluorides.
• the object of the present invention is precisely to provide a technique which, applied to alkaline fluorides, or even to alkaline earth fluorides, makes it possible to significantly increase their reaction kinetics.
• Another object of the present invention is to provide an activation process which makes it possible to significantly accelerate the exchange reactions between fluorine and halogens of higher atomic number, and in particular the exchange reactions between fluorine and chlorine. It is undoubtedly advisable here to recall some essential elements of the exchange reaction between fluorine and halogens of higher atomic number.
• one of the techniques most used to manufacture a fluorinated derivative consists in reacting a halogenated derivative, generally chlorinated, to exchange the halogen (s) with one or more fluorine (s) of mineral origin.
• a halogenated derivative generally chlorinated
• an alkali metal fluoride is used, most often of a high atomic weight such as for example potassium, cesium or rubidium fluorides.
• the fluoride used is potassium fluoride which constitutes a satisfactory economic compromise.
• the high atomic alkali cations such as cesium cations and rubidium cations are phase transfer catalysts.
• the reaction is carried out at a temperature lower than that used for a conventional reaction, that is to say without the actinic activation according to the present invention.
• the reaction is generally carried out in a solvent and, in this case, it is preferable to carry out the reaction with actinic activation at a temperature of at least 10 ° C, advantageously 20 ° C, preferably 40 ° C lower than that of the temperature limit usually accepted for said solvent used.
• the microwaves are emitted in short periods (from 10 seconds to 15 min) alternating with cooling phases.
• the respective durations of the microwave emission periods and the cooling periods are chosen so that the temperature at the end of each microwave emission period remains below a fixed initial temperature which is general lower than that of the resistance of the ingredients of the reaction mixture.
• the invention can also carry out the invention according to a procedure in which the reaction mixture is subjected simultaneously to microwaves and to cooling.
• the power released by the microwaves is then chosen so that, for a fixed initial temperature, generally that of operation, it is equivalent to the energy evacuated by the cooling system and this to heat released or absorbed by the reaction.
• the claimed activation method also has the advantage of being compatible with a continuous operating mode.
• This mode of use advantageously makes it possible to overcome the problems of heat exchange which may be generated during the opening and closing operations of the reactor where the microwaves are emitted.
• the materials to be activated are introduced continuously via an inlet orifice into the reactor where they undergo activation by microwave and the activated products are continuously discharged from said reactor via an outlet orifice. .
• microwaves are preferably used at a frequency of 300 MHz to 3 GHz.
• the frequency used is generally 2.45 GHz and the associated wavelength is close to 12 cm in the air, the penetration of the electromagnetic field can vary between 2 and 10 cm depending on the importance of the losses.
• the power released by the microwaves is between 2 and 100 watts per gram of reaction mixture.
• phase transfer catalysts As has been mentioned before, the presence of a phase transfer catalyst is useful, even necessary for the smooth running of the reaction.
• the best phase transfer catalysts that can be used are generally oniums, that is to say they are organic cations whose charge is supported by a metalloid.
• phase transfer catalysts can also be either represented by or used in the presence or absence, preferably in the presence, of a particularly heavy alkaline cation and therefore of high atomic rank such as the cations of cesium and rubidium.
• phase transfer catalyst is preferably chosen from oniums, cesium or rubidium cations and their mixtures.
• this cation transfer catalyst when the nucleophile is an anion, this cation transfer catalyst can then also play the role of counterion of this anion.
• Cesium fluoride is a compound illustrating very particularly this variant of the invention. It leads to completely satisfactory results.
• phase transfer catalysts than those mentioned above can be used as soon as these phase transfer catalysts are positively charged. They may thus be encrypted cations, for example crown ethers encrypting alkalis. However, the latter are not preferred because of their cost and chemical instability. During the study which led to the present invention, it was shown that the action of microwaves on oniums in the presence of a large amount of fluorides was extremely detrimental to the survival of this transfer catalyst. phases.
• the chloride ion is a good candidate for reducing the degradation of oniums during the reaction.
• the reaction is carried out in the presence of chlorides in an amount greater than once the equivalent amount of said unstable onium.
• the alkali or alkaline earth fluoride is at least partially present in the form of a solid phase.
• the fluoride is a fluoride of an alkali metal with an atomic number at least equal to that of sodium and preferably is a potassium or cesium fluoride.
• fluorides that can be used there are also complex fluorides of the KHF 2 type. However, preference will be given to the use of fluorides which do not carry a hydrogen atom.
• Chlorine / fluorine exchange is also the technique in which the use of microwaves has proven to be the richest in the future.
• a dipolar aprotic solvent a solid phase consisting at least partially of alkaline fluorides and a cation promoting the reaction, said cation being a heavy alkali or a cationic organic phase transfer agent.
• the content of alkali metal cation when used as promoter is generally greater than 5%, advantageously between 1 and 5%, and preferably between 2 and 3 mole% of alkali fluoride used.
• the reagent can comprise, as promoter, phase transfer agents which are oniums (organic cations, the name of which ends with onium).
• Oniums generally represent 1 to 10%, preferably 2 to 5 mol% of the alkaline fluoride, the counter ion is indifferent but most often halogen.
• the preferred reagents are tetraalkylammoniums of 4 to 28 carbon atoms, preferably of 4 to 16 carbon atoms. Tetraalkylammonium is generally tetramethylammonium.
• halex-type aprotic solvent advantageously has a significant dipole moment.
• epsilon is advantageously at least equal to around 10, preferably the epsilon is less than or equal to 100 and greater than or equal to 25.
• the oniums are chosen from the group of cations formed by the columns VB and VIB as defined in the table of the periodic classification of the elements published in the supplement to the Bulletin of the Society
• said suspended solid In general, it is known that a fine particle size has an influence on the kinetics.
• said suspended solid it is desirable for said suspended solid to have a particle size such that its d 90 (defined as the mesh allowing 90% by mass of the solid to pass) is at most equal to 100 ⁇ m, advantageously at most equal to 50 ⁇ m, preferably at most equal to 200 ⁇ m.
• the lower limit is advantageously characterized by the fact that the d 10 of said suspended solid is at least equal to 0.1 ⁇ m, preferably at least equal to 1 ⁇ m.
• the ratio between said alkaline fluoride and said substrate is between 1 and 1.5, preferably around 1.25 with respect to the stoichiometry of the exchange.
• the mass content of solids present in the reaction medium is advantageously at least equal to 1/5, advantageously 1/4, preferably 1/3.
• the agitation is advantageously carried out so that at least 80%, preferably at least 90% of the solids, is kept in suspension by the agitation.
• the aryl radical in question is preferably depleted in electrons and at an electronic density at most equal to that of benzene, preferably at most close to that of a halobenzene.
• This depletion may be due either to the presence in the aromatic cycle of a heteroatom such as for example in pyridine, quinoline. Obviously, electronic depletion can also be caused by electro-attracting groups.
• said aryl advantageously carries at least one substituent on the same nucleus as that carrying chlorine, said substituent preferably being chosen from attractor groups by inductive effect or by mesomeric effect as defined in the reference work in organic chemistry " Advanced organic chemistry "by MJ MARCH, 3rd edition, publisher Willey, 1985 (see in particular pages 17 and 238).
• pseudohalogen is intended to denote a group the departure of which leads to an oxygenated anion, the anionic charge being carried by the chalcogen atom and the acidity of which, expressed by the Hammett constant, is at least equal to that of the acetic acid, advantageously at the second acidity of sulfuric acid and preferably that of trifluoroacetic acid.
• this type of pseudohalogen mention may in particular be made of sulfinic and sulphonic acids, perhalogenated on the carrier carbon. sulfur as well as the perfluorinated carboxylic acids in ⁇ of the carboxylic function.
• the tests were carried out on orthonitrochlorobenzene, ONCB.
• the KF and the ONCB are weighed beforehand in glass bottles.
• KF and the catalyst if necessary
• the walls of the reactor are then rinsed with the added sulfolane using a syringe.
• the reaction medium is irradiated by microwaves and, if possible, opened at the end of irradiation. Cooling is accelerated by an ice bath.
• the reaction mixture is entrained with dichloromethane, filtered through a frit in order to separate the solid which is washed with dichloromethane.
• the dichloromethane is distilled from the organic phase with a rotary evaporator. The residual phase is then analyzed by HPLC.
• reaction medium is irradiated (3 min. 300 W) without catalyst with the stoichiometries: 1 eq. ONCB, 1, 13 eq. KF, 1.05 eq. TMS0 2 .
• the irradiation is carried out in the presence of Me 4 NCI 4% molar catalysts in a diluted or undiluted medium.
• the microwave irradiation time is increased by accumulating sequences of 3 min at 300 W with return to ambient temperature between each sequence.
• Table 1 shows the results obtained. The results observed are as follows: O 00/58215 ⁇
• the reagents used are identical to those used in Example 1.
• reaction medium is irradiated (3 min. 300W) without catalyst with the stoichiometry: 1 eq. ONCB, 1, 13 eq. KF, 1.05 eq. TMS0 2 .
• the temperature value recorded at the opening of the reactor for this type of test (test A) varies from 150 to 160 ° C.

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Citations (3)

• 1999
  • 1999-03-31 FR FR9904035A patent/FR2791660B1/fr not_active Expired - Fee Related
• 2000
  • 2000-03-31 CA CA002366448A patent/CA2366448A1/fr not_active Abandoned
  • 2000-03-31 AU AU36645/00A patent/AU3664500A/en not_active Abandoned
  • 2000-03-31 JP JP2000607927A patent/JP2002540055A/ja not_active Withdrawn
  • 2000-03-31 WO PCT/FR2000/000827 patent/WO2000058215A1/fr not_active Application Discontinuation
  • 2000-03-31 EP EP00915275A patent/EP1181246A1/fr not_active Withdrawn

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