Europaisches Patentamt J European Patent Office 00 Publication number: 0 456 157A1 Office europeen des brevets EUROPEAN PATENT APPLICATION @ Application number: 91107313.8 © int. ci.5: C07C 43/313, C07C 317/16, C07D 319/06, C07C 41/56 ® Date of filing: 06.05.91 ® Priority: 07.05.90 JP 117111/90 © Applicant: KUREHA CHEMICAL INDUSTRY CO., LTD. © Date of publication of application: 9-11, Horidome-cho, 1-chome Nihonbashi 13.11.91 Bulletin 91/46 Chuo-ku Tokyo 103(JP) © Designated Contracting States: @ Inventor: Ishizuka, Makoto DE FR GB IT 3-1-15-1001, Honcho Kawaguchi-shi, Saitama-ken(JP) Inventor: Wakasugi, Takashi 55-1, Nishikimachi Sekishita Iwaki-shi, Fukushima-ken(JP) Representative: Boeters, Hans Dietrich, Dr. et al Boeters & Bauer Bereiteranger 15 W-8000 Munchen 90(DE) © Process of producing chloroacetals. © A process of producing a high-pure acyclic or cyclic chloroacetal with a good yield by a simple step of reacting a monochloroacetaldehyde trimer or a monochloacetaldehyde monomer obtained by heating the trimer in the existence of an acid catalyst and a monohydric or dihydric alcohol having from 1 to 5 carbon atoms in the existence of an acid cata- lyst or a dehydrating agent. CO m a. LU Rank Xerox (UK) Business Services EP 0 456 157 A1 FIELD OF THE INVENTION covering it. Thus, the method is disadvantageous as an industrial production method. This invention relates to a process of producing Furthermore, in the production method (4) of an acyclic or cyclic chloroacetal from a monoch- cyclic acetals using chloroacetals as raw materials, loroacetaldehyde trimer. 5 chloroacetal which is the raw material for the meth- od is expensive and further in the case of syn- BACKGROUND OF THE INVENTION thesizing, for example, 2-chloromethyl-1 ,3-diox- olane which is a 5-membered acetal form Hitherto, as a process of producing chloroacetaldehyde diethyl acetal, there is scarece- chloroacetals, there are known (1) a method of io ly difference in boiling point between the raw ma- subjecting chloroacetaldehyde and an alcohol to a terial and the desired product, therefore the pu- dehydration reaction with anhydrous calcium chlo- rification of the product is difficult. ride as described in West German Patent 1,235,880, (2) a method of reacting a , 0-dich- SUMMARY OF THE INVENTION loroethyl alkyl ether and an alcohol as described in 75 Japanese Patent Publication (unexamined) No. 63- The invention relates to a novel production 287739, and (3) a method of obtaining 1,2- process of an acyclic or cyclic chloroacetal made dihaloethyl acetate by a halogenation of vinyl ace- for solving the aforesaid problems in the conven- tate and reacting the product with an alcohol as tional production processes of chloroacetals. described in British Patent 2,146,016 and U.S. Pat- 20 An object of this invention is to provide a ent 4,532,338. Also, (4) a method of reacting an process of producing chloroacetals capable of pro- acyclic chloroacetal and a dihydric alcohol as a ducing high-pure acyclic or cyclic chloroacetals process of producing a cyclic chloroacetal is known with a good yield. as described in Japanese Patent Publication Other object of this invention is to provide a (unexamined) No. 61-166829. 25 process of producing chloroacetals capable of in- However, in the aforesaid production method dependently carrying out the production step of the (1) using chloroacetaldehyde as the raw material, raw materials for chloroacetals and the production chloroacetaldehyde having a concentration of at step of the chloroacetals. least 80% is required but chloroacetaldehyde is a A further object of this invention is to provide a very unstable compound and can not store for a 30 process of producing chloroacetals by a simple long period of time. Accordingly, when production step without need of using a large chloroacetaldehyde is used as the raw material for amount of dehydrochloric acid agent and without producing chloroacetal, the production of need of recovering a large amount of acetic acid chloroacetalaldehyde and the production of by-produced. chloroacetal must be carried out continuously, 35 As the result of the investigations for attaining whereby the production steps become complicated the aforesaid objects, the inventors have discov- and are industrially disadvantageous. ered that the aforesaid objects can be attained by Also, in the production method (2) of using a , using a chloroacetaldehyde trimer which can stably jS-dichloroethyl alkyl ether as a raw material, the exist as the raw material for produce the acetal and production of the raw material for the formation of 40 have succeeded in accomplishing the present in- acetal and the production of chloroacetal can be vention based on the discovery. separately carried out but since the reaction is a That is, according to an embodiment of this dehydrochloric acid reaction of the raw material invention, there is provided a process of producing and an alcohol, a dehydrochloric acid agent such acyclic or cyclic chloroacetals, which comprises as triethylamine, tributylamine, etc., is required. 45 reacting a monochloroacetaldehyde trimer and a Accordingly, after the reaction, the recovery step of monohydric or dihydric alcohol having from 1 to 5 the dehydrochloric acid agent is necessary, which carbon atoms in the existence of an acid catalyst make the prodution step complicated. Also, the or a dehydrating agent. method is unsuitable for the production of cyclic Furthermore, according to another embodiment acetals. 50 of this invention, there is provided a process of In the production method (3) of starting the producing acyclic or cyclic chloroacetals, which chlorination of vinyl acetate, after chlorinating vinyl comprises heating a monochloroacetaldehyde acetate in benzene, an alcohol is added thereto to trimer in the existence of an acid catalyst to form a aging overnight, and after separating a benzene monomer thereof and reacting the monomer and a layer, the reaction is completed by an azeotropic 55 monohydric or dihydric alcohol having from 1 to 5 dehydration. Accordingly, the production faculty is carbon atoms in the existence of an acid catalyst low and a large amount of acetic acid is by- or a dehydrating agent. produced, which requires an equipment for re- EP0 456 157 A1 DETAILED DESCRIPTION OF THE INVENTION usually unnecessary but in the reaction with a viscous glycol, a solvent may be used for improv- Then, the invention is described in detail. ing the stirring effect and carrying out the reaction A monochloroacetaldehyde trimer (hereinafter, quickly. In such a case, as solvents, organic sol- "monochloroacetaldehyde" is referred to as 5 vents, e.g., high-boiling organic solvents such as "MCA") is a white crystal having a melting point of 1 ,2-dichlorobenzene, etc., are preferably used. ° from 87 c to 88° C and can be easily obtained by The reaction temperature is at least 120° C, dissolving a liquid containing MCA as the main and preferably from 120°C to 160°C under at- component in an organic solvent such as hexane, mospheric pressure or pressure. The reaction is etc., and cyclizing MCA in the existence of sulfuric io carried out at such a temperature for 1 to 50 hours, acid as described in Japanese Patent Publication and preferably 2 to 30 hours. If the reaction tem- ° (unexamined) No. 2-223575. perature is lower than 120 C, the MCA trimer is Since the MCA trimer is a stable compound not sufficiently depolymerized, which is undesira- and can be stored for a long period of time, the ble. MCA trimer may be previously prepared and thus 75 After the reaction is over, by distilling the reac- the production of chloroacetals of this invention can tion product, a high-pure desired chloroacetal can be carried out independently from the production of be obtained with a high yield. the MCA trimer. As described above, an MCA trimer may be As an aliphatic alcohol for producing an acetal used for the reaction with an alcohol as it is but by reacting with the MCA trimer, a monohydric or 20 after forming a MCA monomer by heating the MCA dihydric alcohol having from 1 to 5 carbon atoms is trimer in the existence of an acid catalyst to per- used and examples thereof are monohydric al- form the depolymerization thereof, the MCA mon- cohols such as methanol, ethanol, propanol, n- omer may be used for the reaction with an alcohol. butanol, sec-butanol, ter-butanol, etc., and glycols An MCA trimer reproduces high-pure MCA by such as ethylene glycol, propylene glycol, butyiene 25 heating the trimer to a temperature of from 120° C glycol, etc. to 130° C in the existence of an acid catalyst such Since the acetal forming reaction is almost as diluted sulfuric acid, para-toluenesulfonic acid, quantitatively carried out, it is better to use a etc. After forming MCA, by reacting MCA with an stoichiometeric amount of the alcohol. alcohol in the existence of an acid catalyst or a As the catalyst for reacting the MCA trimer and 30 dehydrating agent as in the case of the MCA alcohol, an organic acid or an inorganic acid trimer, a chloroacetal is obtained but in this case, an ° such as para-toluenesulfonic acid, an acid ion-ex- the reaction temperature is at least 30 C, and °C change resin (e.g. , a perfluorosulfonic acid resin), preferably from 40 to the refluxing temperature. zeolite, etc., is used. The amount of the acid cata- The process of this invention includes the process lyst being used is from 0.1 to 8% by weight, and 35 of reproducing MCA from an MCA trimer and reac- preferably from 0.2 to 6% by weight to the amount ting the MCA with an alcohol as described above.