Patent Publication Number: US-3878227-A

Title: Process for making tert.-butyl glycidyl ether

Description:
United States Patent Sexton et al.  
 [ Apr. 15, 1975 PROCESS FOR MAKING TERT.-BUTYL GLYCIDYL ETHER Inventors: Arthur R. Sexton; Frederick P.  
 Corson, both of Midland, Mich.  
 The Dow Chemical Company, Midland, Mich.  
 Filed: Dec. 7, 1973 Appl. No.: 422,806  
 Assignee:  
 U.S. Cl. 260/348.6; 260/615 R Int. Cl C07d l/l8 Field of Search 260/348 R References Cited UNITED STATES PATENTS l/l95l Zech 260/348 R 3,743,679 7/1973 Hickner et al. 260/348 R OTHER PUBLICATIONS Ulbrich et al., Chem. Abstr. 61, 3049 (1964),  
 Primary Examiner-Norma S. Milestone Attorney, Agent, or Firm-Chessie E. Rehberg [57] ABSTRACT 4 Claims, No Drawings FOR MAKING TERT.-BUTYL GLYCIDYL ETI-IER BACKGROUND or THE INVENTION Evans and Edlundflnd. Eng. Chem., 28 1186 (1936) and US. Pat. Nos. 1,968,033 and 1,968,601, disclose that certain tertiary olefins readily react with primary alcohols in the presence of acid catalysts to produce the corresponding tert.-alkyl ethers of the alcohol.  
 PROCESS Leum and Macuga,U.S. Pat. No. 2,480,940 disclose 2. treating the intermediate with NaOI-I. Their overall yield was about 76%. No other record has been found of the preparation of a tert.-alkyl glycidyl ether.  
 SUMMARY OF THE INVENTION According to the invention, tert.-butyl glycidyl ether is prepared in good yield from inexpensive and readily available materials by a process wherein l. isobutylene is reacted with a glycerol a-monohalohydrin, thus to produce essentially a mixture of l-, 2- and l,2-tert.-butyl ethers of the halohydrin, 2. the mixture of ethers from (1) is reacted with a dehydrohalogenating agent, thus to convert the 1- ether to tert.-butyl glycidyl ether, while leaving essentially unchanged the 2- and the l,2-ethers&#39;and 3. the tert.-butyl glycidyl ether is separated and the other two ethers are recycled to Step (I). Among the advantages of the above process are the following:  
 a. no tertiary butanol, a relatively expensive material,  
  isneeded, b. separation of the mixed ethers produced in Step l is not necessary before proceeding to Step (2),  
  c. in Step (2) it is unexpectedly found that the ring closure of the l-ether is highly selective and can be effective essentially completely with only slight reaction of the Z-ether, and  
 d. the undesired 2- and l,2-ethers of the halohydrin can be recycled to Step (1) and thus converted essentially completely to the desired glycidyl ether.  
 DETAILED DESCRIPTION OF THE INVENTION The reactions involved in the process can be exemplified as follows:  
 +HOCH CHOHCH (1) CH C-(CH )=CH 2 (CH C--OCH [CH OC (CH (2) I II III NaOH (CH3) c-ocH In Step (I) the predominant product is I, with a minoramount of III and even less of II.  
 The preferred glycerol monohalohydrins are the chloroand bromohydrins, the former being favored rate into aqueous and organic phases and the latter is- Cl+ (CH3) C-OCH because of its lower cost.  
  In Step (2) the dehydrohalogenating agent may be any conventional agent that is useful for converting a vicinal halohydrin to the corresponding epoxide. As a practical matter, the alkali and alkaline earth metal hydroxides, particularl&#39;ysodium hydroxide; are preferred.  
  Step (I) is conveniently conducted at a temperature of about 50-60C. and at least the autogenous pressure, using about 1.0-1.25 moles of isobutylene per mole of monohalohydrin and an acid catalyst, such as I a sulfonic acid or a strong acid ion exchange resin. Suit- Step (2) is suitably conducted at about ordinary ambient temperature (20-30C.) and with a slight excess (-1 10% of theory) of dehydrohalogenating agent.  
 The latter is preferably aqueous NaOH of about 15-25% by weight concentration. While the entire crude product from Step (1) can be used in Step (2). it is usually preferred to first separate the unconverted glycerol monochlorohydrin from the mixture. This can be conveniently done by extraction with water. The extracted water-soluble material, after removal of the. wa ter, is recycled to Step (1).  
  The course of the reaction can be-followed by-analyzing the reaction mixture for unreacted tert.-butyl 3-chloro-2-hydroxy-l-propyl ether. When this has substantially disappeared, the mixture is allowed to sepaseparated and distilled to obtain the final product, tert.- butyl glycidyl ether. The fractions containing 2-butoxy- 3-chlorol -propanol and 2,3-dibutoxyl chloroproparie can be recycled to Step (l) and ultimately converted to the desired ether.  
  The practice of the invention is illustrated by the following examples.  
 Step (ll Reaction of Isobutene with Glycerol a- Monochlorohydrin CHOHfLH Cl I I (CH C-OCH (CH OH)CH Cl vII ]CH Cl III  4 III 2 A series of experiments was run wherein the reaction temperature was 50-60C. and the reaction was continued until the composition of the reaction mixture became essentially constant (about 6 to 8 hours). The mixture was then analyzed for the following four components:  
  A. Unreacted monochlorohydrin compound l. l-Butoxy-3-chloro-2-propanol ll. 2-Butoxy-3-chloro-l-propanol i 33 lll. l.2-Dibutoxy-3-chloropropane 10 1| :5 The results are summarized in Table I. The products 1 11 fig are reported as moles of each component per mole of Total 244.67 A fed to the reactlon.  
 TABLE 1 Products. Moles per lsohutylcne. Mole of (A) Fed Example Catalyst 91 of Theory A I 11 Ill 1 PTSA 1 10 0.145 0.612 0.036 0.166 2 120 .231 .573 .024 .111 3 125 .170 .558 .058 .219 4 Dowex 100 .1 15 .680 .025 .107 5 110 .92 .614 .039 .147  
 &#39;pfl&#39;nlucnesull&#39;onic acid (0.2% by wt. based on (A) fed) Duwex resin 50 WXX-H (1.2% by wt. based on (A) fed) Run No. 2  
  In other experiments similar to those above, it was found that isethionic acid was essentially equivalent to PTSA &#39;as a catalyst.  
 EXAMPLE 6 A series of pilot plant runs was made in which the glycerol a-monochlorohydrin (A) used was made in situ by the reaction of water with epichlorohydrin.  
 Run No. 1  
 &#39; The kettle was charged with 43 gals. of deionized water. 200 g. of p-toluenesulfonic acid monohydrate and the kettle closed to the atmosphere. The mixture was heated to 75C. and 185 lbs. of epichlorohydrin pumped in at 75-90C. over a period of 4 hours. Occasional cooling was required to control the temperature. The mixture was held at&#39; 90C. an additional 2 hours. A sample was analyzed by VPC and showed no unreacted epichlorohydrin.  
  The contents of the kettle were cooled to 50C. and the water distilled off at 100 mm. Hg abs. and finally at mm. Hg while slowly increasing the kettle temperature to 90C. This required 6 hours. &#39;7  
  The kettle contents were cooled to 50C and 1 12 lbs. (2 moles) of isobutylene added at 50-60C. and 30-40 p.s.i.g. over a period of 7.5 hours. The temperature was then held at 50-60C. an additional 6 hours. There was no pressure drop during the last 3 hours.  
  The kettle contents were cooled to C. and 175 lbs. of toluene added followed by 10 gals. of deionized water. The mixture was agitated for 5 minutes after adding the water and then allowed to settle for )2 hour. The aqueous phase was drained and the washing operation repeated 3 more times. The wash waters (369 lbs.) contained 13% organic (48 lbs.), 93% or 44.5 lbs. of which was glycerine monochlorohydrin, the remainder being polymer. This wash water was saved for the next run.  
  The oil layer was topped at 100 mm. Hg absolute up to a pot temperature of 100C. to remove the toluene.  
  The reactor was charged with the wash water from the above run which contained the recovered glycerine monochlorohydrin (0.4 lb. mole), 200 g. of fresh p-toluenesulfonic acid and 15.5 gals. of deionized water which made a total of 25 lb. moles of water. Epichlorohydrin (194 lbs. or 2.1 lb. moles) was added as before over a 5 hour period.  
  The remainder of the reaction was carried out as before adding 2.5 lb. moles of isobutylene.  
  The wash waters weighed 415.5 lbs. and contained 81 lbs. of glycerine monochlorohydrin and 7 lbs. of polymer. This was again&#39;saved for the next run.  
  The toluene distilate contained 3.47 lbs. of 1-tert.- butoxy-3-chloro-2-propanol, only a trace of the 2- isomer and diether. This was saved for the next run.  
 The residue weighed 296 lbs. and assayed as follows Since 11 and 111 can be recycled as demonstrated in the following experiment, the yield of I 9.53 X IOU/10.615 89.7%.  
 Transalkylation of 2-tert.-butoxy-3-chloro-l-propanol 11 and the Diether 111 A 1500 g. sample of the above materials consisting of 80% diether 111 (5.4 moles), 20% 2-tert.-butoxy-3- chloro-l-propanol 11 (1.82 moles) was mixed with 800 g. (7.25 moles) of glycerine monochlorohydrin and g. of p-toluene-sulfonic acid and heated at 9598C. for 2 hours.  
  The resulting mixture was cooled, mixed with 1500 cc. of toluene and the diluted mixture extracted 3 times with 500 cc. of water each time. The water layer on distillation gave 422 (3.82 moles) of glycerine monochlorohydrin.  
  The oil layer on being distilled gave 7.65 moles of ltert.-butoxy-3-chloro-2-propanol l, 0.75 moles of 2- tert.-butoxy-3-chloro-l-propanol I1 and 1.12 moles of diether lll. Thus, 59% of ll and 79% of lll were converted to 1. Most of the remainder could be converted by further recycling.  
  Step (2) Reaction of l-Tert.-Butoxy-3-Chloro-2-Propanol, (1), With NaOH EXAMPLE 7 above was stirred overnight at room temperature with a by weight aqueous solution of 8.4 m. of NaOH.  
 The aqueous phase was then separated and extracted. twice with 500 cc.of toluene. The toluene extract was added to the organic phase and-the latter then extracted three times with 250 cc. of water. The final wash water was neutral and free of NaCl. The oil layer was then distilled under reduced pressure to yield 7.64  
 &#39; m. of tert.-butyl glycidyl ether, 0.715 m. of ll, 1.89 m.  
 of 111 and 70 g. of residue. This represents a yield of 97.5% of glycidyl ether and shows that 11 and lll are essentially inert to NaOl-l under those conditions.  
 EXAMPLE 8 A kettle was charged with 735 lbs. of crude isobutylated glycerol monochlorohydrin containing 3.39 moles of 1-tert.-butoxy-3-chloro-2-propanol, 500 lbs.  
 of 35.2% NaOH (4.4 moles), 277 lbs. of wash water from an earlier run and 14 gallons of deionized water. Cooling water was maintained on the jacket throughout the run so as to hold the temperature at 2325C.  
  After 16 hours, VPC analysis of the oil phase showed no unreacted 1-tert.-butoxy-3-chloro-2-propanol. The two phases were separated and the oil phase washed 3 times with 10 gal. of water each time. The three wash waters were combined, a sample extracted with CH Cl and the extract assayed by VPC. This showed the water extract contained 11.2 lbs. of tert.-butyl glycidyl ether and 9 lbs. of highers.  
  The final oil layer weighed 741 lbs. and assayed as follows:  
 Compound Lbs.  
  Toluene 76.3 tert.-Butyl glycidyl ether 427.26  
  II 61.0 lll 137.4 Polymer 39.0  
  Total tert.-butyl glycidyl ether, 438.5 lbs. 3.37 moles. Yield based on l-tert.-butoxy-3 chloro-2- propanol taken, 99.5%.  
 We claim:  
  l&#39;. The process for making tertiary-butyl glycidyl ether comprising 7 l. butylating :1 glycerol a-monohalohy drin by reaction with isobutylene, thus to produce a mixture of the land 2-tert.-butyl monoether s and the 1,2-di- (tert.-butyl ether) of .the halohydrin;  
 2. selectively dehydrohalogenating the l-monoether by reaction with a dehydrohalogenating agent, thus to produce tert.&#39;butyl glycidyl ether; and  
 3. separating the glycidyl ether from the remaining halohydrin ethers and recycling the latter to Step (1 2. The process of claim 1 wherein wthe halohydrin is chlorohydrin.  
  3. The process of claim 1 wherein the dehydrohalogenating agent is an alkali or alkaline earth metal hydroxide.  
  4. The process of claim 1 wherein glycerol a-monochlorohydrin is reacted with isobutylene and the resulting mixture of ethers is dehydrochlorinated by reaction with aqueous sodium hydroxide.  
  UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENTNO.: 3,878,227  
 DATED 1 April 15, 1975 WVENTORG) A. R. Sexton and F. P. Corson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 Column 1, line 43, delete &#34;effective&#34; and insert -effected;  
 Column 2, line 50, delete (ll) and insert (l) Column 5, line 29, delete &#34;13.6 g. and insert -l35.6 g.7  
 Column 5, line 43, delete &#34;those&#34; and insert --these.  
 Signed and Sealed this twenty-ninth Day Of July 1975 [SEAL] Arrest:  
 RUTH C. MASON C. MARSHALL DANN Arresting ()jflcer Commissioner ofPatenrs and Trademarks