Patented Mar. 29, 1932 1,851,832 UNITED STATES PATENT office BRUCE WILMOTHENDERSON, OFFARNWORTH, WIDNEs, AND JoHN GARNETTPERCI WAL, OF WIDNES, ENGLAND, ASSIGNORS To IMPERIAL CHEMICAL INDUSTRIES LIMITED, OF LONDON, ENGLAND MANUFACTURE AND PRODUCTION OF BENZoyL CEORDE No Drawing. Application filed November 21, 1928, Serial No. 321,031, and in Great Britain February 2, 1938. This invention relates to an improved meth trate how the said invention may be carried od of preparing aromatic acid chlorides and into practical effect but the invention is not in particular benzoyl chloride as hereinafter restricted to these examples. described. It is already known that benzoyl by weight. - - - - - The parts are chloride can be prepared by the chlorination of benzaldehyde. Eacample 1 55 According to the present invention, benzoyl 214 parts of benzyl alcohol are heated in a chloride is obtained by the chlorination of flask fitted with an efficient reflux condenser. benzyl alcohol. This reaction has been hith Chlorine is passed through the liquid at from 0. erto unknown and although the reaction is a 180 to 140 degrees centigrade for about 6 complex one, it may be represented by the hours, i.e. until chlorine is noticeable in the exit. The reaction temperature is then raised empirical formula:- to from 190 to 200 degrees centigrade and the 1. CHCH-OH +2C1 = CH-COCl+3HCl reaction product allowed to reflux for an The hydrochloric acid enters into the reaction wother 6 hours. The chlorine which is read and if desired a mixture of chlorine and ily taken up when the temperature is raised hydrochloric acid may be used instead of begins to be noticeable in the exit again when chlorine alone, as shown in the following the reaction is finished. The contents of the formula:- flask are then distilled and the fraction com ing over at between 194 to 198 degrees centi 2. CHCH.OH+HCl+2Cl,- grade is collected as benzoyl chloride. A 70 CHCOCl+4HCl yield in Weight of 209 parts or 70 per cent, In practice it is convenient to combine this is obtained. reaction with the ordinary method of chlorin Eacample 2 25 ating benzaldehyde to obtain benzoyl chlo 15 cwts, of a mixture of benzyl alcohol and ride, so that instead (of first preparing a pure benzaldehyde (obtained by hydrolysis of 75; benzal chloride to be converted into benzalde crude benzal chloride) are charged into a lead hyde) the crude product used is obtained by lined chlorinator fitted with a reflux condens chlorinating toluene to say 54. Tw. This er. The temperature is raised to about 150° 30 consists of a mixture of benzyl chloride and centigrade and chlorine is allowed to pass into benzal chloride. On hydrolysis in the usual the liquid, the hydrochloric acid being al 80 way it gives a mixture of benzyl alcohol and lowed to escape. After about 20 hours chlo benzaldehyde which is the parent material. rination, when chlorine is passing freely to On chlorinating this parent material until the exit, the chlorination is stopped, refluxed 35 excess chlorine comes through freely we ob and distilled over into receivers. About 13 tain pure benzoyl chloride. cwts. of benzoyl chloride are obtained. This method is much cheaper than the old What we claim is:- method of chlorinating benzaldehyde because 1. The step in the manufacture of benzoyl 40 the starting point, viz. crude benzal chloride, chloride comprising the reaction of free is very much less costly than pure benzal chlorine with hydrolized benzyl chloride. 90 chloride. Benzyl chloride alone or any mix 2. The step in the manufacture of the ben ture of the same with benzal chloride may be Zoyl chloride, comprising the reaction of employed. chlorine, in admixture with hydrochloric Other aromatic acid chlorides, for exam acid, on benzyl alcohol. ple, chlor benzoyl chloride may be prepared 3. The manufacture of benzoyl chloride by 95 in an analogous manner by the action of Cl the action of free chlorine on mixtures of on hydrolyzed chlor benzal chlorides, or on a hydrolized benzyl chloride and benzal chlo hydrolyzed mixture of chlor benzyl chloride ride. 50 and chlor benzal chloride. 4. The manufacture of benzoyl chloride b The following examples will further illus the action of free chlorine on benzyl E. 100 2 1,851,883 5. The manufacture of benzoyl chloride comprising the step of hydrolizing mixtures of benzyl and benzal chloride in any propor tion, and the step of treating with free chlo Zaldehyderine the mixture resulting of frombenzyl said alcohol hydrolization. and ben ste. O The manufacture of benzoyl . chloride -. comprising the step of hydrolizing mixtures 10 of benzyl and benzal chloride in any propor tion, and the step of treating with free chlo rine and hydrochloric acid the mixture of benzylalcohol and benzaldehyde resulting from said hydrolization step. . 5 In testimony whereof we have signed our namesBRUCE to this specification.WILMOT HENDERSON. . . . JOHN GARNETT PERCIWAL.
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