DEP0049205DA - Process for the production of unsaturated aldehydes. - Google Patents

Description

Dr Alfred Max Paquin Frankfurt / M-Niederrad, February 5th, 50

Donnersbergstrasse 24 ■

Appendix II ρ ^ gO ^ JW ^ o ^

to register the
Dr Alfred Max Paquin, Frankfurt / M

for a patent on a
Procedure for B ^; »32eM4hr4y} g .--- de ^^^^

^ he unsaturated aldehydes ieruALdölsiaf '©.

It is known to convert aldehydes into their waste oils by means of dilute alkalis fren-ene unsaturated] / aldehydes z-u-ieridensieren. It has also become known that the same condensation with the help of the salts of secondary Amines or secondary amino acids (sarcosine).

Primary amines have not hitherto been used as condensation agents, since it would appear to be obvious that they are useful would not be suitable for this purpose.

The surprising observation has now been made that salts of primary amines in catalytic amounts not only also aldol condensation cause, but that they are also particularly effective aldolizing agents, which an aldoicondensation Allow to carry out in a considerably shorter time than is the case with the known condensation agents. Their effect is so strong that even the small amounts of amine salt that are produced by neutralizing the traces contained in all technical aldehydes of acids with primary amines are sufficient to form aldol condensation in just a few minutes at a slightly elevated temperature To effect the amount of 60-80 $ the amount of aldehyde.

If increased amounts of primary amine salt (about $ 3-5, the amount of aldehyde) are used, or if, after adding free acid, the possibility of forming the same is given by additional free acid, the yield of products of the aidol stage can be increased to over $ 90 .

The aldol condensation can be carried out by various methods, depending on the desired product of the aidol stage. gen, To the aldehyde, the acid content of which has been increased by acidification, is entered?

1) either just the amount of primary amine required for neutralizer, free acid, and aldol condensation. In this case, the usual aldolization product is obtained

3-e after — cler — A ^ —d-es ^ by what-

unsaturated aldehyde i

2) or the amount of primary amine required both to neutralize the free acid and to form the Schiff base of the aldehyde For these two purposes, different primary amines can also be used one after the other, for example Double-sided Schiff bases can be made from diamines for the second purpose., By hydrolysis The Schiff base with dilute mineral acid is then obtained as unsaturated.

Al d ehy d. -. Bias »JLaEf. ahr, @ n -.- 4s4-v0n - fe

voltage of the unsaturated aldehyde is desired, but is normally a -Äldöl ^r ent st eh s "" dignity.

If the purification of the unsaturated aldehyde is difficult, for example by distillation, this can also be done! £ The unilateral Schiff base formed from the monoacid salt of a diamine can be recrystallized or it can also be seen after liberation of the Schiff base, with a free amino group through / Eraktionier ^ it » to be cleaned since. spontaneously rearranged them into the te-

.. trahydroimidazole derivative easily distilled the easily distilling oxazolidine derivative surrounds the latter, as well as the tetrahydroimidazole derivative. store look back into the chains form back when the ship's bases are heated with dilute mineral acid for the purpose of hydrolytic cleavage »

The aldol condensation and recovery of the unsaturated aldehydes ier-Äidotstftfe, which can easily be carried out by the process of this patent is of great technical importance, since the varied responsiveness of the latter is largely for the most diverse Purposes can be exploited.

Examples

Example 1. To a mixture of 116 G.T..propionaldehyde containing 0.7 G.

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T. propionic acid contains, with 29 G.T.Water with stirring 2.40 g. T. glacial acetic acid was added and then 7.20 G.T. of a 25% aqueous M ethyl amine solution, which neutralizes the total acid, entered. The mixture is then stirred for 11 hours at 40-45 ° and for 1- & hours at 50-55 °. 2-methyl-penten- (2) -al is then obtained by distillation in a yield of $ 91.

Example 2. To a mixture of 144 GTButyraldehyd containing 1.2 GT butyric acid, 36 GTWasser 2.18 GTEisessig are added with stirring and then added 3.65 GTButylamin, which is the total acid neutralisiert.Danach 1% hours at 40 45 ° and stirred for 1 hour at 50-55 °. 2-ethyl-hexen (2) -al is obtained by distillation with a yield of 89%.

Example 5. To a mixture of 144 GT isobutyraldehyde containing 0.9 GT isobutyric acid, 36 pbw of water 2.38 GTEisessig are added with stirring and then added 3.65 GTIsobutylamin, which is the total acid neutralisiert.Danach H- hours at Stirred 40- <45 ° and 11 hours at 50-55 °. Then dewatered at 50 ° under reduced D ^r 'ICE and it remains behind Isobutyraldol with a yield of 87%.

EXAMPLE 4. 146 pbw of isobutylamine are added to the not yet dehydrated reaction liquid obtained according to example 3 while stirring at 45-50 ° within half an hour and stirring is continued for an hour at this temperature. With simultaneous elimination of water from the aldol, Schiff's base khh 2 is formed , 2,4-trimethylpentene- (3) -isobutylamine, which is mixed with 130 parts by weight of water and 265 parts by weight of 37% hydrochloric acid and kept at the boil with stirring for f hours on the reflux condenser. After removing the aqueous layer, washing until neutral and drying At 50 ° under reduced pressure, 2,2,4-trimethyl-periten- (3) -al is obtained in a yield of 82%. _B_gi game 5) To the aqueous reaction liquid obtained near Example 3, 62.5 GT ethylenediamine 96%, which is diluted with the same amount of water, are added at 35-40 ° with stirring and i

After stirring at 40-450, you get crude ethylene-di- (2,2,4-trimethyl-pentene- (3) -) - amine, which by distilling off the

term ^v iinter reduced pressure at a temperature up to 100 "to a large extent is purified. The hydrolysis is then carried dureh addition of 264 and 600 GTWasser GTSalzsäure 37% and i-hour boil at Rückflusskühler.Naeh removal of the aqueous layer is 2,2,4 -Trimethyl-penten- (3) -al obtained in the manner described. Yield over 80% *

Example 6. 128 GT ethanolamine 96% are added to the still water-containing reaction liquid obtained in Example 3 with stirring at 35-40 °, with half-hourly stirring at 40 °. After dewatering under reduced pressure at 50 °, the viscous Schiff base is fractionated under reduced pressure. is first stored back into the chain form with 12% hydrochloric acid in the manner described and split into 2,2,4 »trimethyl-pentene- (3) -al by hydrolysis. Yield over 80%.

at Example 7. The still water-containing reaction liquid obtained according to Example 3 is added to a solution of 193 parts by weight ethylenediamine monoehlorhydri in 193 parts by weight water at 35-40 ° with stirring in 20 minutes and -J-Stuii / ie. bej. this temperature naehgerührt.Naeg stripping de & flüehtigen ^ obtained at 50 ° under reduced pressure, 2,2,4-trimethyl-pentene (3) -äthylendiaminehlorhyärat as an amorphous mass, which allmählieh krystalliniseh erstarrt.Naeh recrystallization from ethanol is QQ%, the compound received in pure form.

The work-up can, however, also be carried out as follows; the chlorine hydrate is taken up in water and made glkaliseh with sodium hydroxide solution and the free oily base is taken up in ether. The dried base is fractionated in a stream of nitrogen in a good vacuum 'what' after the spontaneous rearrangement into l, l, 3-trimethyl-buten- (2) -hexahydroimidazole is easy to do. This is converted into the hydrochloric acid in the usual way with 12% hydrochloric acid after storage Salt of the Schiff see base and hydrolytic cleavage 2,2,4-trimethyl-penten- (3) -al won.

Claims (1)

Pat entans prueh
Process for fi ^ -eh # ä-frrra% ^ unsaturated aldehydes ^ d-er ^ l-del-s ^ uf e ^ uöfe »ν © r ~ ZÄ &igi; .ßii ~ Ald ehy den, dadur Gh g ek ennζ ei chn et, das s -aj * f Al d ehyde primär§r solutions of salts or amine ^ smf free acid toi Wass.er.-en.thal.t.enAe ,, aldehydes primary ^ Amin§, at temperatures between _Ο; and 100 ° are used in a quantity of ¹ to exposure that Naeh neutralization of the acid amine salts in a-Mfnge, - © v, n ¹ '5§ iAdad ^ ^ l LEAD - du-reh-ihr e ^a About f ihrttng-in Schi ff 'see, bases, l „r.Qclei ·. · Aminp _i ä.thyl ^ .S.eh.if., i: ls _i Gh.e- _; Bases, * © $ - the latter ^ possibly close to their faction - 4, _r tion, ^v hydrülytiseh split v / ground. For the truth the inventor λ "J /" *. ". V & JIjUjuu February 6, 1950 Dr Alfred Max Paquin