DE1941632C - Process for the pure preparation of 1 acetoxy 3 methylbut 2 en 4 al - Google Patents

Claims (1)

The establishment concerns a new process for pure, secondary, tertiary or mostly quaternary Representation by l-Aceto \ v.-3-methylhui-2-en-4-al (I) carry ammonium groups. Among the metallic Katiunen Q 'become sodium, potassium and liariuni Ac O CH. CH C CIIO preferred. I I 5 Strongly nuclcophilic (basic) anions are /. Ii. CIL ₁ chloride, hruinide. Iodide, hydroxyl, cyanide, carhonai. Hydrogen carbonate, phosphate, acylates, alcoholates Ac acetyl, starting from technical mixtures and phenates. The Niicleophilie of the anion Y ~ is supposed to from 1.2-niaceii). \ y-3-nieihylbutan-4-al (H) and 1,2-di- be at least about as strong as in the chloride ion. aceUixypentan-5-al (HI). iq The preferred amounts of the catalyst Q Y It is known that 1-aceto-3-methylbut-2-en-4-al (I) are between 0.01 and I ⁰ Z ₁₁ , and the preferred By reacting hexamethylenetetramine with temperatures in the range from 70 to 130 C. ¹ i-chloro-2-methyl-4-aceto \ y-2-butene and then normally the reaction is carried out without lo- Use the preparation agent to complete the process of the complex obtained, but it is also possible to len (vui. British patent 736 4HK), the unity of an inert solvent or diluent However, the benefits of the process are small. work. For this purpose, z. And hydrocarbons Fs is also known to compound 1 by reacting such as benzene, toluene, petroleum ether, ligroin and subsii- of (-i-chloro- or ei-bromotighnaldehyde with alkaline hydrocarbons such as anisole, oder Lrdalkaliaeetat (cf. German interpretative document. The course and end of the reaction are shown on the basis of the 1227 000) or easy to determine by rearrangement of 2-formyl-20 split off acetic acid. To 2-hydro \ y-bui-3-en or its acetate in the presence of removing the acetic acid, optionally the solvent of copper or copper compounds (cf. lowering agents and the catalyst, this can be national patent application 6 810 954). Remaining mixture of I and III due to the However, these methods are relatively complex. Different physical properties are easy Separate technical mixture of approximately equal parts at 25, z. B. extractive or preferably by de- 1,2-Diacetoxy-3-methylbutan-4-al (II) and 1,2-distillation under reduced pressure. For example Aceioxypvnian-5-al (III), on the other hand, is obtained at a boiling point of I at 6 Torr at 84.degree. C. and III at 135 to 140.degree. fold way by hydroformylation of 1,2 - di- The process gives high yields of the organic acetoxybut-3-en (IV) with a carbon monoxide synthesis important l-acetoxy-3-methylbut- Hydrogen mixture using rhodium as a catalyst 3 ° 2-en-4-al (I) without the isomeric 1-acetoxy- goal. The compounds II and III , however, are only pent-2-en-i Λ (V) to a significant extent, extremely difficult to separate because theirs. 11th Boiling points are closely spaced and because they are out-of-example which are not thermally stable. One can use the 117 g of an equal mixture of II and III mix, although deacetylated, but then you get at 35 with 0.2 v. anhydrous sodium acetate 1 hour The usual procedure is again a mixture of isomers, heated to 110 ° C. for a long time. The processing of the namely from I and the l-acetoxypent-2-cn-5-al (V). mischcs provides I in 89 ⁿ _'o yield; Bp. 84 C. This mixture is just as difficult to separate 6 Torr, like the original from II and III. B · i s η i e I "> The object of the invention was therefore the Rcindarstel- 4 « Development of the compound I from the isomers mentioned- 27 g of an equal-part mixture of II and III Mix necessary for the synthesis of compounds with 0.2 g of barium hydroxide for 15 minutes the vitamin A rule is particularly important. heated to 1 H) C. The work-up delivers I in 84 ° / _o sodium A method of reducing yield has been established. l-Accto \ y-3-methylbut-2-en-4-al, based on tech- 45 example 3
mixtures of 1,2-DiafeU> \ y-3-methylbutane 4-al and 1,2-1) iacelo \ ypentan-5-al, found which 46.1 of my identical mixture of I! and III is characterized by it. that one is the starting with I g of a basic, tertiary ammonium Mixture at 30 to 180 C with an ion exchanger containing 0.001 to 10 weight groups (handcls- percentage (based on the amount of the mixture) with 50 bczeichmmg LKWATIT * MP62) for 30 minutes a salt-like catalyst QY treated, 100 ⁰ C heated. Work-up gives I in 93% strength Q 'an ammonium cation or an alkali metal cation Yield. or the equivalent of an alkaline earth metal cation or Example 4
of a polyvalent ammonium exchanger means and Y for a strongly nuclcophilic anion or, if this 55 485 g of a mixture of> »30 ⁿ / _n I.2-Diacetoxy- is polyvalent, the equivalent of it, stands, and the pentan-5-al (145 g) and 70 ^ft / ₀ !, i-diacctoxy-J-methyl- cntstandcnc! • Acetoxy>3'methyl'but-2-en-4-al of butane-4-al (340g) are mixed with 10 ml of a 25 ° / _o igcn the unchanged 1,2-Diacetoxypcntan-5'al in usual aqueous solution of NaCl and the obtained rather separates way. Examples of suitable cations Mixture heated to 110 ° C. for 4 hours with stirring. Q are the cations of the general lormel NR ₁ ', 60 Workup provides I ^rt in 82 / _o yield, in which the radicals R are identical or different can and denote hydrogen or alkyl radicals, as in claim: in the cations NII, ¹ , tetramethylammonium, tri- methylammonium, dimelhylammonium, Mclhylam- process for the purification of 1-acetoJiy- monium, Methyläthylammoniiim, 11 this series is 65 3-methylbut »2-en-4-al, starting from technical also hear the Anionenaiislaiischci, which are mixtures of 1,2-L) iacetoxy-3-methyl * butun-4-al mostly to cross-linked insoluble macromolecular and U-Diacetuxypcntan-S-al. thereby Prevention acts, which characterize a multitude of pri- | L-misch hci if) his IKO C mil 0.001 his HKiL- ^ iehlspro / enl (hang on clic quantity ties Cie-Wisdies) with a saline catalyst Q 'Y
treated, where at Q an ammuimkaiion olIlt an alkali metal cation or the equivalent of a (iilalkali metal cation or a polyvalent anion exchanger hedeuiei iiiul N fin em a strongly nucleophilic anion or, if this is low, the equivalent thereof: stone, and is created | -Aceio \ v-.1-ineth> l-hiii-2-eii- · - .il around the other parts 1.2-l) iaLei <i \ ^ penian-v.il in a similar way.