PREPARATION OF ALKOXY HALIDES

Abstract: Alkyl alkoxy, aryl alkoxy or alkylaryl alkoxy halides are prepared by reacting an alcohol, phenol or alkyl with ethylene and/or propylene oxide in the presence of a soluble metal or compound of a metal of Groups IA or IIA of the Periodic Table as catalyst to form an alkoxy alcohol and directly reacting the alkoxy alcohol with a halogenating agent in the continuing presence of the catalyst. Costs are reduced and product yields are improved.

Description: PREPARATION OF ALKOXY HALIDES This invention relates to a process for the preparation of alkyl alkoxy, aryl alkoxy or alkylaryl alkoxy halides which are suitable for use as intermediates in the preparation of surfactants. Numerous attempts have been made to develop surfactant compositions for use in enhanced oil recovery and the patent literature is replete with descriptions of formulations, see for example, USP's 4,424,135, 4,159,037, 4,110,228, 4,066,124 and 4,018,278. A useful summary of the art is given in Kirk-Othmer's Encyclopedia of Chemical Technology, Third Edition, Volume 17, pages 168-182. This indicates that most compositions contain (a) a main surfactant which is either a petroleum sulphonate or a synthetic hydrocarbyl sulphonate and (b) co-surfactants which include simple alcohols, ethoxylated alcohols and sulphated ethoxylated alcohols. It has also been disclosed that alkyl and alkylaryl polyalkoxy alkylene sulphonates may be used as co-surfactants. These compounds are generally prepared by a three-stage process. In the first stage of a typical process an alcohol or alkyl phenol is condensed with an alkylene oxide in the presence of sodium or potassium hydroxide to form an alkoxylate. This is then halogenated by treatment with thionyl or sulphuryl chloride, usually in the absence of a catalyst. Finally the halide is converted to a sulphonate by reaction with sodium sulphite, again, usually in the absence of a catalyst. The alkali catalyst must be removed after the alkoxylation reaction since its presence is harmful to the stability of the product. We have now discovered a process for the production of alkoxy halides from alcohols or phenols in which a single soluble inorganic catalyst is employed. Thus according to the present invention there is provided a process for the production of an alkyl alkoxy, aryl alkoxy or an alkylaryl alkoxy halide which process comprises reacting an alcohol of formula R1-OH, phenol or an alkyl phenol of formula: EMI2.1 wherein R1 is an alkyl group containing 1 to 24, preferably 8 to 20, carbon atoms, R2 is an alkyl group containing 1 to 24, preferably 8 to 20, carbon atoms and R3 and R4 are hydrogen atoms, or R2 and R3 are both alkyl groups containing 1 to 12 carbon atoms and R4 is a hydrogen atom, or R2, R3 and R4 are each alkyl groups wherein the sum of the number of carbon atoms in the groups is in the range 3 to 24, with ethylene oxide and/or propylene oxide in the presence of a soluble metal or compound of a metal of Groups IA or IIA of the Periodic Table as a catalyst, to form an alkyl alkoxy, aryl alkoxy or alkylaryl alkoxy alcohol, containing 1 to 15, preferably 4 to 10, alkoxy units per molecule, and directly reacting the reaction product with a halogenating agent in the continuing presence of the catalyst. Suitable catalysts include the chlorides, hydroxides, alkoxides and alkanoates of lithium, magnesium, calcium, strontium and barium. Other suitable catalysts include the above compounds of sodium, potassium, rubidium and caesium solubilised by a solubilising agent. Suitable agents include dipolar aprotic solvents such as dimethyl sulphoxide, crown ethers and polyalkoxy compounds containing three or more alkoxy groups per molecule such as dimethyl polyethylene glycol. A catalyst promoter may be employed if desired. Known promoters for alkoxylation catalysts include phenols, carboxylic acids, polyols, aldehydes, ketones, amines, amides and inorganic acids. The alkoxy distribution may be determined by the choice of catalyst. If a broad distribution is desired then the catalyst is preferably a lithium compound. If, on the other hand, a narrow distribution is preferred then the catalyst is preferably a compound of a Group IIA metal together with a promoter. preferred halogenating agents are chlorinating agents such as thionyl chloride and sulphuryl chloride. A pressure in the range of atmospheric to 7 bar may be employed for the alkoxylation stage. Pressure is not a significant parameter for the halogenation stage and this reaction is therefore most conveniently carried out at atmospheric pressure. Alkoxylation is suitably carried out at a temperature in the range 1000 to 260"C, preferably 1200 to 190"C, and halogenation is suitably effected at a temperature in the range 30 to 1200C, preferably 750 to 85 C. The molar ratio of alkoxy alcohol to halogenating agent in the halogenation stage is suitably in the range 1:1 to 1:5, preferably 1:1 to 1:1.5. The quantity of catalyst employed is preferably in the range 0.1 to 10% by weight, preferably 0.2 to 1%, expressed as a percentage by weight of the alcohol, phenol or alkyl phenol. The reactions may be effected in the presence or, preferably, the absence of a solvent. Suitable solvents include 1,2-dichloroethane, toluene and chloroform. The process according to the present invention possesses the following advantages: (1) A single catalyst can be used for both alkoxylation and halogenation reactions thus saving the cost of employing separate catalysts for each reaction; (2) Neutralisation of the product and/or catalyst removal from the alkoxylation stage is no longer necessary. (3) Hydrated salts or bases do not require special drying (water is usually removed after catalyst addition in alkoxylation reactions prior to the introduction of the alkylene oxide). (4) Salts or bases are slow to dissolve in the halogenation mixture if added at this stage and thus the halogenation reaction may be adversely affected. When, however, the catalyst is previously employed in the alkoxylation stage, it is already solubilised. (5) Cheaper compounds such as hydroxides or alkoxides may be employed as catalysts. (6) The catalyst is readily recoverable by filtration or by extraction with water. As a result of the reduced reaction time in the halogenation stage, the tendency of the polyoxyalkylene chain to cleave, liberating 1,4-dioxan in the case of a polyoxyethylene chain as noted by Robinson et al, J. Soc. Cosmet. Chem., 31, 329-337, is reduced. Thus both the yield and selectivity as indicated by the matching of the alkoxy distribution in the alcohol and the halide are improved and product contamination with unwanted by-product is reduced. The invention is illustrated with reference to the following Examples. Example 2 is not in accordance with the invention and is provided for comparison. Example 1 Hexadecanol was treated with strontium hydroxide (1X w/w) and phenol (1.5% w/w) at 1000C for one hour under vacuum to remove water to a level of 0.07% w/w. It was then reacted with ethylene oxide at 125"C under 4 bar pressure for 5 hours to incorporate 4 moles ethylene oxide per mole alcohol. The unrefined ethoxyalcohol C16H33(0CH2CH2)40H (54.8g, 0.131M) was heated with stirring at 80"C with thionyl chloride (16.8g, 0.141M). 13C NMR (Nuclear Magnetic Resonance) spectroscopy indicated 90% conversion to ethoxychloride after 2 hours and GLC (Gas Liquid Chromatography) indicated the production of 0.02 moles of 1,4-dioxan per mole ethoxyalcohol. Example 2 Hexadecanol was treated with potassium hydroxide (0.3% w/w) at 100"C, under vacuum to remove water. It was then reacted with ethylene oxide at 125"C under 4 bar pressure for 5 hours to incorporate 4 moles ethylene oxide per mole alcohol. The unrefined ethoxyalcohol C16H33(0CH2CH2)40H (50.0g, 0.120 M) was heated with stirring at 80 C with thionyl chloride (15.4g, 0.129M). 13C NMR spectroscopy indicated 26X conversion to ethoxychloride after 2 hours and GLC indicated the production of 0.2 moles of 1,4-dioxan per mole ethoxyalcohol. It should be noted when comparing Examples 1 and 2 that the effective ethoxylation-chlorination catalyst of Example 1, (strontium ion), resulted in a chlorination rate 3.5 times greater than in Example 2, the case where the ethoxylation catalyst is an ineffective chlorination catalyst. 1,4-dioxan production was 10 times greater in the uncatalysed chlorination than in the catalysed chlorination. A low chlorination rate, similar to that of Example 2, would be expected if the potassium compound were removed following ethoxylation. This is usually performed as a routine operation. The examples illustrate the value of leaving suitable ethoxylation catalysts in the ethoxyalcohol to effect catalysis of the chlorination stage.

Claims: Claims:- 1. A process for the production of an alkyl alkoxy, aryl alkoxy or an alkylaryl alkoxy halide which process comprises reacting an alcohol of formula R1-OH, phenol or an alkyl phenol of formula: EMI6.1 wherein R1 is an alkyl group containing 1 to 24 carbon atoms, R2 is an alkyl group containing 1 to 24 carbon atoms and R3 and R4 are hydrogen atoms, or R2 and R3 are both alkyl groups containing 1 to 12 carbon atoms and R4 is a hydrogen atom, or R2, R3 and R4 are each alkyl groups wherein the sum of the number of carbon atoms in the groups is in the range 3 to 24, with ethylene oxide and/or propylene oxide to form an alkyl alkoxy, aryl alkoxy or alkylaryl alkoxy alcohol, containing 1 to 15 alkoxy units per molecule, characterised by the fact that the reaction is carried out in the presence of a soluble metal or compound of a metal of Groups IA or IIA of the Periodic Table as a catalyst, and the reaction product is directly reacted with a halogenating agent in the continuing presence of the catalyst. 2. A process according to claim 1 wherein R1 is an alkyl group containing 8 to 20 carbon atoms, or R2 is an alkyl group containing 8 to 20 carbon atoms and R3 and R4 are hydrogen atoms, and the alkoxy moiety contains 4 to 10 alkoxy units per molecule. 3. A process according to either of the preceding claims wherein the catalyst is selected from the group consisting of the chlorides, hydroxides, alkoxides and alkanoates of lithium, magnesium, calcium, strontium and barium. 4. A process according to either of claims 1 or 2 wherein the catalyst is selected from the group consisting of the chlorides, hydroxides, alkoxides and alkanoates of sodium, potassium, rubidium and caesium solubilised by a solubilising agent. 5. A process according to claim 4 wherein the solubilising agent is selected from the group consisting of dipolar aprotic solvents, crown ethers and polyalkoxy compounds containing three or more alkoxy groups per molecule. 6. A process according to any of the preceding claims wherein the alkoxylation reaction is effected at a temperature in the range 100" to 2600C. 7. A process according to any of the preceding claims wherein the alkoxylation reaction is effected at a pressure in the range atmospheric to 7 bar. 8. A process according to any of the preceding claims wherein the halogenation reaction is effected at a temperature in the range 300 to 1200C. 9. A process according to any of the preceding claims wherein the molar ratio of alkoxy alcohol to halogenating agent is in the range 1:1 to 1:5. 10. A process according to any of the preceding claims wherein the halogenating agent is thionyl chloride or sulphuryl chloride.

Inventors: HODGSON, PHILIP KENNETH GORDON, STWEART, NEVIN JOHN
Applicants: THE BRITISH PETROLEUM COMPANY P.L.C.
Application year: 1985
Main classification: C07C43
IPC codes: C07C67, C07C41, B01J31, C07C43, B01J23, B01J27, C07B61