PREPARATION OF ALKOXY HALIDES

Abstract: Alkyl-, aryl- or alkylaryl-alkoxy halides are prepared by reacting the corresponding alkoxy alcohol with a halogenat­ ing agent, e.g., thionyl chloride, in the presence of an amide as catalyst. In addition to being faster, the catalysed reaction results in an increased yield of desired product and a decrease in the tendency of the polyoxyalkylene chain to cleave.

Description: PREPARATION OF ALKOXY HALIDES This invention relates to a process for the preparation of alkyl alkoxy, aryl alkoxy or alkylaryl alkoxy halides 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 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. We have now discovered that the use of an amide catalyst in the second stage, the halogenation stage, results in a shorter reaction period and an increased yield of desired product. Thus according to the present invention there is provided a process for the production of an alkyl, aryl or alkylaryl alkoxy halide which process comprises reacting an alkyl-, aryl- or alkylaryl-alkoxy alcohol of formula R - (ORl)m OR wherein R is an alkyl group, containing 1 to 24, preferably 8 to 20, carbon atoms, a phenyl group or an alkyl aryl group of formula: : EMI2.1 wherein 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 K4 is a hydrogen atom, or R2, R3 and K4 are each alkyl groups wherein the sum of the number of carbon atoms in the groups is in the range 3 to 24; R1 is an alkylene group containing 2 or 3 carbon atoms; and m is a number in the range 1 to 15, preferably 4 to 10, with a halogenating agent in the presence of an amide as catalyst. Suitable amide catalysts include aliphatic amides, phosphoramides and ureas and their hydrochlorides. Suitable aliphatic amides include N,N-dimethylformamide and acetamide. Preferred halogenating agents are chlorinating agents such as thionyl chloride and sulphuryl chloride. The reaction is suitably effected at a temperature in the range 30 to 12O0C, preferably in the range 750 to 85"C. Pressure is not a significant parameter and the reaction is therefore most conveniently carried out at ambient pressure. The molar ratio of alkoxy alcohol to halogenating agent is suitably in the range 1:1 to 1:5, preferably 1:1 to 1:1.5. The quantity of catalyst enployed is preferably in the range 0.1 to 5% by weight, expressed as a percentage by weight of the alkoxy alcohol. The reaction may be effected in the presence or, preferably, the absence of a solvent. Suitable solvents include 1,2-dichloroethane, toluene and chloroform. As a result-of the reduced reaction time, the tendency of the polyoxyalkylene chain to cleave liberating 1,4-dioxan, 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 1, however, is not in accordance with the invention and is provided for comparison. Example 1 61.lg (O.11M) of the ethoxy alcohol C18B37Ph(OCR2CB2)5OB was heated with stirring at 800C with 13.9g (0.12M) thionyl chloride in the absence of catalyst and solvent. 13C NMR (Nuclear Magnetic Resonance) spectroscopy indicated quantitative conversion to ethoxychloride after 3 hours and GLC (Gas Liquid Chromatography) indicated the production of 0.07 mole of 1,4-dioxan per mole ethoxy alcohol. Example 2 64.6g (O.llM) of the ethoxy alcohol C18B37Ph(OCH2CH2)50H was heated with stirring at 800C with 14.7g (0.12M) thionyl chloride and 0.65g (1X) N,N-dimethylformamide in the absence of solvent. 13C NMR spectroscopy indicated quantitative chlorination after 0.25 hours and GLC indicated the production of 0.008 mole of 1,4-dioxan per mole ethoxy alcohol. Example 3 67.0g (0.12M) of the ethoxy alcohol C18H37Ph(OCH2CH2) 50H was heated with stirring at 800C with 15.2g (0.13M) thionyl chloride and 0.67g (1Z) urea in the absence of solvent. 13C NMR spectroscopy indicated quantitative chlorination after 1 hour and GLC indicated the production of 0.01 mole of 1,4-dioxan per mole ethoxy alcohol. Example 4 62.lg (O.llM) of the ethoxyalcohol CL8B37Ph(OCEI2CH2)50H was heated with stirring at 800C with 14.2g (0.12M) thionyl chloride and 0.62g (1Z) acetamide in the absence of solvent. 13C NMR spectroscopy indicated quantitative chlorination after 2 hours and GLC indicated the production of 0.03 mole of 1,4-dioxan per mole ethoxyalcohol. When compared with Example 1, Examples 2, 3 and 4 show a substantial decrease in dioxan production when a catalyst in accordance with the invention is used, together with a considerable increase in the chlorination rate.

Claims: Claims: 1. A process for the production of an alkyl-, aryl- or alkylarylalkoxy halide which process comprises reacting an alkyl, aryl, or alkylaryl alkoxy alcohol of formula: R-(ORl)mOH wherein R is an alkyl group containing -1 to 24 carbon atoms, a phenyl group, or an alkylaryl group of formula: EMI5.1 wherein 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; R1 is an alkylene group containing 2 or 3 carbon atoms; and m is a number in the range 1 to 15, with a halogenating agent, characterised by the fact that the reaction is carried out in the presence of an amide as catalyst. 2. A process according to claim 1 wherein R is an alkylaryl group of formula EMI5.2 wherein R2 is an alkyl group containing 8 to 20 carbon atoms and m is a number in the range 4 to 10. 3. A process according to either of the preceding claims wherein the catalyst is an aliphatic amide, a phosphoramide or urea. 4. A process according to claim 3 wherein the aliphatic amide is N,N-dimethylformamide or acetamide. 5. A process according to any of the preceding claims wherein the halogenating agent is thionyl chloride or sulphuryl chloride. 6. A process according to any of the preceding claims wherein the halogenation reaction is effected at a temperature in the range 30 to 1200C. 7. 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. 8. A process according to any of the preceding claims wherein the quantity of catalyst employed is in the range O.1Z to 5% by weight, expressed as a percentage by weight of the alkoxy alcohol.

Inventors: HODGSON, PHILIP KENNETH GORDON, STEWART, NEVIN JOHN
Applicants: THE BRITISH PETROLEUM COMPANY P.L.C.
Application year: 1986
Main classification: C07C43
IPC codes: C07C43, B01J31, C07C67, C07C41, C07B61