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Preparation of O-(2-Hydroxyalkyl) Oximes

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Preparation of O-(2-Hydroxyalkyl) Oximes ^ ^ H ^ I H ^ H ^ II ^ II ^ H ^ ^ ^ ^ ^ H ^ H ^ ^ ^ ^ ^ I ^ � European Patent Office Office europeen des brevets EP 0 775 107 B1 (12) EUROPEAN PATENT SPECIFICATION (45) Date of publication and mention (51) |nt CI.6: C07C 249/12, C07C 251/54 of the grant of the patent: 13.10.1999 Bulletin 1999/41 (86) International application number: PCT/EP95/03001 (21) Application number: 95930419.7 (87) International publication number: (22) Date of filing: 28.07.1995 wo 96/04238 (15.02.1996 Gazette 1996/08) (54) PREPARATION OF 0-(2-HYDROXYALKYL) OXIMES VERFAHREN ZUR HERSTELLUNG VON 0-(2-HYDROXY)OXIMEN PREPARATION DE 0-(2-HYDROXYALKYLE) OXIMES (84) Designated Contracting States: • MOHR, Jiirgen AT BE CH DE DK ES FR GB GR IE IT LI NL PT SE D-67269 Griinstadt (DE) • GEHRER, Eugen (30) Priority: 02.08.1994 DE 4427289 D-67069 Ludwigshafen (DE) • LAUTH, Giinter (43) Date of publication of application: D-23562 Liibeck (DE) 28.05.1997 Bulletin 1997/22 (56) References cited: (73) Proprietor: BASF AKTIENGESELLSCHAFT EP-A- 0 655 437 US-A-3 965 177 67056 Ludwigshafen (DE) • CHEMICAL ABSTRACTS, vol. 68, no. 11, 11 (72) Inventors: March 1968, Columbus, Ohio, US; abstract no. • HARREUS, Albrecht 49175, J. WOLF ET AL. page 4747 ; cited in the D-67063 Ludwigshafen (DE) application & PL,A,53 525 • GOTZ, Norbert • CHEMICAL ABSTRACTS, vol. 73, no. 7, 17 D-67547 Worms (DE) August 1970, Columbus, Ohio, US; abstract no. • RANG, Harald 35231, J. WOLF ET AL. page 316 ;& PL,A,59 077 D-67122 Altrip (DE) • R. KLAUS ET AL. 'ACS Symposium Series 443, • HARTMANN, Horst 1991, Chapt. 18, p. 226-235' , AMERICAN D-67459 Bohl-lggelheim (DE) CHEMICAL SOCIETY , WASHINGTON cited in the application see page 231, scheme 9 Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 75001 PARIS (FR) EP0 775 107 B1 Description [0001] The present invention relates to a process for the preparation of 0-(2-hydroxyalkyl)oximes of the general formula I R3 C = N 0 CH2 CH OH (I) , 10 R2- in which R1 and R2 each stand for an alkyl group having from 1 to 10 carbon atoms, or form, together with the carbon atom to which they are attached, a 5-membered to 7-membered cycloalkyl radical, and R3 denotes an alkyl group is having from 1 to 10 carbon atoms. [0002] 0-(2-hydroxyalkyl)oximes have great significance as intermediates for plant protectants (cf eg, the prior Ger- man Application DE-A 44 15 887). [0003] Furthermore, it is well known that it is possible to cause reaction of acetone oxime with ethylene carbonate in toluene in the presence of potassium fluoride to produce 0-(2-hydroxyethyl)acetone oxime (cf. Amer. Chem. Soc. 20 Symposium Series 443 page 231 (1 991 )). [0004] Furthermore, a process for the preparation of bis[0-(2-hydroxyethyl)dimethyl-glyoxime starting from dimeth- ylglyoxime and ethylene carbonate is described in J. Polymer Sci., 10, page 3408 (1972). [0005] In accordance with the earlier application EP-A 655,437, aldoximes and ketoximes with unsubstituted or C-,- C8-alkyl-substituted ethylene or propylene carbonate can be hydroxyalkylated in the presence of catalytic amounts of 25 an N-alkylated, stable organic base or of pyridine substituted by a secondary amine. [0006] It was the object of the invention to provide a more economical process for the preparation of 0-(2-hydroxy- alkyl)oximes I. [0007] Accordingly, we have found a process for the preparation of 0-(2-hydroxyalkyl)-oximes of the formula I, where- in a ketoxime of the formula II 30 R1. N OH (ID , R 35 is caused to react with a carbonate of the formula III in the presence of a catalyst. so [0008] The following literature citations "Houben-Weyl" refer to Houben-Weyl, Methoden der Organischen Chemie, 4th ed., Thieme Verlag, Stuttgart. [0009] Preferred process products I are those which can be produced by this process variant those are preferred in which R1 and R2 stand for C-1-C4 alkyl groups and primarily C-1-C3 alkyl groups or form, together with the carbon atom to which they are attached, a cyclopentyl or cyclohexyl ring, and in particular those in which R1 and R2 stand for methyl 55 and/or ethyl or form, together with the carbon atom to which they are attached, cyclohexyl. R3 preferably stands for a C-1-C4 alkyl group, particularly for ethyl and more particularly for methyl. Most particularly preferred compounds I are those in which R1, R2 and R3 stand for methyl. [0010] The ketoximes II are generally known or are obtainable by known methods, for example, by the reaction of 2 EP0 775 107 B1 the corresponding ketones with hydroxylamine. [0011] The carbonates III are also generally known or can be produced by known methods (cf. eg, EP-A 543,249). [0012] Reaction of ketoximes II with carbonates IV in the presence of a catalyst: 10 0 0 R1, 1 I C = N OH + H2C CH R3 II III 15 R3 R 1 Catalyst \ | ^ 20 C = N O CH2 CH OH + C02 25 [0013] The molar ratio of carbonate III to ketoxime II is usually from 1:1 to 10:1 and in particular from 4:1 to 7:1 . [0014] Suitable catalysts, used either alone or in the form of a mixture, are a) alkali metal salts, alkaline earth metal salts, and ammonium salts (NH4+), primarily the potassium salts and also the sodium salts' with inorganic or organic anions such as alkali metal halides, hydroxides, carbonates, hydrogen 30 carbonates, alcoholates, and alkali metal salts of organic monocarboxylic acids. By way of example, there may be mentioned potassium fluoride, potassium iodide, potassium hydroxide, potassium carbonate, potassium hy- drogen carbonate, potassium methylate, potassium ethylate, potassium tertbutylate, and potassium acetate; P) ammonium salts and preferably phosphonium salts having at least one organic group in the cation and containing 35 inorganic or organic anions, primarily the halides, hydrogen carbonates, and acetates of such phosphonium salts in particular those containing three C-1-C4 alkyl and/or phenyl groups, such as tri-n-butylphosphonium acetate and triphenylphosphonium chloride; phosphines having at least one but preferably three C-organic radicals, in particular those selected from the 40 group comprising C-|-C10 alkyl, C6-C15-aryl, C6-C15 alkylaryl, and/or C7-C10-arylalkyl, such as, primarily tri-n-butyl- phosphine and triphenylphosphine; or 8) triethylamine. 45 [0015] Preferred catalysts are those which are mentioned under (a) and (8). Of the (a) group, the potassium salts are preferably used, especially potassium fluoride or potassium hydrogen carbonate. [0016] The catalyst, primarily the inorganic alkali metal salts and the alkali metal salts of carboxylic acids, can be bonded to a support, if desired. Examples of suitable supports are aluminum oxide, silica gel, and kieselguhr. The amount of catalyst in these supported catalysts is usually from 10 to 50 wt%. so [0017] The catalysts are usually employed in an amount of from 5 to 50 mol%, preferably from 5 to 30 mol%, and more preferably from 5 to 10 mol%, based on the ketoxime II. [0018] The reaction can be carried out in a single, preferably aprotic, organic solvent or in a solvent mixture. However, the process is preferably carried out without the use of a solvent, in which case an excess of the carbonate III can, in particular, serve as reaction medium. 55 [0019] Suitable solvents are for example alkylbenzenes, such as, in particular, toluene and also the xylenes, further- more dialkylketones such as methyl ethyl ketone, halobenzenes such as chlorobenzene, and ethers such as 1,4-di- oxane. [0020] The amount of solvent used is usually from 1 to 9 times and in particular from 2 to 7 times the weight of the 3 EP0 775 107 B1 ketoxime II. If the amount of solvent exceeds 9 times the weight of the ketoxime II, conversion and yield usually fall. [0021] The reaction is preferably carried out at temperatures of from 80°C to 150°C and mostly from 100°C to 140°C and pressures of from 0.5 to 1 bar and especially under standard pressure. [0022] The addition of a conventional phase transfer catalyst usually leads to an increase in reaction rate and con- 5 version. However, for simple processing, it is preferred not to use a phase transfer catalyst. [0023] Examples of phase transfer catalysts are quaternary ammonium or phosphonium salts, preferably tetraalky- lammonium, tetraalkylphosphonium, trialkylbenzylammonium, or trialkylbenzylphosphonium salts, especially triethyl- ammonium, tributylbenzylammonium, and tetrabutylammonium chlorides, bromides, and hydrogen sulfates, and also tributylhexaphosphonium bromide. 10 [0024] The phase transfer catalyst is usually employed in an amount of from 0.5 to 2 mol% and preferably from 0.7 to 1 mol%, based on the ketoxime II. [0025] The reaction can be carried out batchwise or, preferably, continuously. [0026] The reaction times are normally from 8 to 24 h but mostly from 8 to 16 h. [0027] The isolation of the reaction product I takes place by methods known per se, preferably by distillation. is [0028] The distillation residues of the crude mixture contain substantially unconverted carbonate III and the catalyst. [0029] In a preferred embodiment of the process of the invention the process is carried out by replenishing the ketoxime II and the carbonate III at a rate equal to the rate of consumption thereof, following the destination of the product I from the reaction mixture, and the reaction is then repeated.
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