DE1793414A1 - Process for the preparation of cyclopentanetetracarboxylic acid-1-cis, 2-cis, 3-cis, 4-cis and their dianhydride - Google Patents

Description

PATENT LAWYERS

DR. MÜLLER-BORE. DIPL-INQ. G
DR. MANiTZ · DR. DELlFEL
β MÜHCHEM 22, ROBERT-KOGH-STa ΐ TELEPHONE 225T10

S 804

Sociebe Ohimiqtie des öharbonnages 9, avenue Pereier

PariB, 8 ^ (legs), Prnnkreioh

Procedure for HüratLLung / on Cyolopenbimfcetracarbonüäure-l-Giö, 2-oio, 3-0la, 4-oiö fionie from their dianhydride,

The invention is met by a 7erfalirßn zuc Uu va to L lung and üiini ^ ung der fiyfiLoponfcfmfcötraearbonaüure-t-öia, 2- «in, 3 nLüf '! - a ((!., IMOA O and from their Dlanhytlrid ((' _; Ρ, ί), λ,) durnh »Jaip;! Beroäureoxydabiou deü 3 _? 6 ~ Kndoßv.; Uiylen-l , 2, J ^ i'-fiiHruhydpophbhaluäuroauliydrLda (Λ> Μ, Ρ>rl; r d3i * ciAtijsprachondon acid concerns dlo l'Uf ^indan,: i. 1 Ui dnroh> lu ancestors orhul tonnn L'i '

ui: il-iViid'i I Ln (If ₁ of '' / cLwjifiiibuntit: l, m; irbrm.iMurti lt; i \ _t ';: iii, j in, 1 i.-i.) lm * i; h »Int po tüi'iifUu ·; i); , hit L on dnti

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3,6-Bndome tiiylen-1, 2,3 * 6-tet rshy drophthal eättre & nhydri d «, which in turn is the addition product of maleic anhydride and cyclopentadiene, is known from the work of Aider. According to known techniques, the nitric acid oxidation either 2 JUtuaer is temperature, with very concentrated nitric acid "which is very long reaction times required at least one week, or not at temperatures of gröesenordnungsmäesig 60 ⁰ C at verhältnisraässig short reaction times (the total for example, 3V2 hours About shouts s) (SIIT a saltpeter Saur ·, (which is kept at a Eonsentration of $ 60>) is performed. in the latter case, the product obtained is verhSltnleaSssig unclean and can be difficult to "purified, for example by TSakristallisierefi in V7üßrigen carboxylic acids. tuck procedures also do not allow the simple and economical recovery of the intermediate products of nitric acid oxidation »Finally, the extraction of the solvent used for the crystallization is a very expensive process«

i> Io the present invention relates to a method aur HerafcelltiMg of Oyolüponbanfcetracarboneäure-i-cis, 2-0i8, l- * uin, 4> * ο1β, παν? ie of the dianhydride, proceeding therefrom

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of 3,6-endomethylene-1,2,3 »6 ~ tetrahydrophthalic anhydride or the corresponding acid »which is characterized by the following steps, individually or in combination:

a) The reaction time is over 12 hours and preferably between 24 and 46 hours at a reaction temperature between 30 and 60 ^° C., preferably 40 and 45 ^° C., and a nitric acid concentration between 60 and 75 %, preferably 65 and 70 °.

b) The molar ratio of nitric acid to 3.6 * » Endomethylene-1,2,3,6-tetrahydrophthalic acid anhydride or the corresponding acid is between 10 and 20, depending on between 10 and 15

c) Crystals of cyclopentanetetracarboxylic acid-i-cis, 2-cis * 3-cis, 4-cie separated from your residual mother liquor are washed with fresh nitric acid, the concentration of which is between 50 and 75 % and preferably between 65 and 70 % .

d) The nitric acid used for washing is used to oxidize a new amount of 3,6-endomethylene-1,2,3,6-tetrnhydrophthalsiiuroanljydrid oüo.t of the corresponding acid.

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e) The remaining mother liquors of the SalpeterBaureoxydation are used to stage the nitric acid oxidation zurtiokgefUhrt circulated _v they naohdem by A "bdestillieren of water back to the desired content of nitric acid are accommodated.

f) This distillation is carried out under reduced Druok, preferably at a pressure below 25 mm Hg, the temperature of the bath or the Helemediuas remains below 80 ^0C.

All of these measures make it possible to jolt one Yields of the order of 80 to 85 #, one Cyolopentanetetraoarboxylic acid-i-oie, 2-ois, 3-cis, 4-cls to achieve which, after drying, contains less than 900 ρρβ * nitrogen, and in particular allows the production Tone of very little colored prayers

In contrast to the acids produced in this way, the acid obtained in this way can be used without any further Purification can be used to produce the corresponding diene hydride of satisfactory dividing quality, the in particular contains less than 100 ppm of Stiokatoff. Ee Let us know to carry out this reaction with the aid of a large excess of marine acid anhydride. Be was

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but now it has been found that this preparation is advantageously effected in that one Hol of the cyclopent ante traoarbonic acid at a temperature between 100 and 140 ⁰ C, preferably between 110 and 120 ⁰ C, with 2 to 4 mol, preferably 2 to 3 Hol , in particular treated 2 to 2.2 moles of acetic anhydride. The use of such proportions of acetic anhydride which essentially correspond to the stoehiometric ratio makes the recovery of the acetic anhydride unnecessary, since it is practically quantitatively converted into the acid. It is known that anhydrideization is generally an easy reaction. In the case of the preparation of cyclopentanetetracarboxylic acid anhydride, it has been found that the yield is almost quantitative even when the amounts of acetic anhydride given above are used.

The CJyolopentanetetracarbonsäure-i-ois, 2-ois, 3-oiB, 4-ois is obtained by the process of the invention suitable for most of the applications known for this product without additional treatment »

If you want a particularly pure cyclopentane tetra carbonic acid-1-oia, 2-cis, 3-cis, 4-cis, you can the cyclopentanetra-

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carboxylic acid with Yorteil duroh Ifcikr is all ize, starting out from their aqueous solution, clean »This recrystallization is advantageously carried out» by the The mother liquors of the crystallization solution are circulated after a proportion of 1 to 25% has been subtracted from them, which is obtained at the stage of concentration of the Residual mother liquors from the nitric acid oxidation are returned back, which prevents the mother liquors from becoming the Recrystallization enriches with impurities. Eb it was found that the acid remaining in the mother liquors of the concentration does not undergo any aerobic degradation learns.

The following examples illustrate the invention without it to restrict

example 1

1.23 kg of 3 »6-endomethylene-1,2,3,6-tθtrahydr © phthalic anhydride (AoM ₉ F.) are gradually mixed with a nitric acid solution, which consists of 5, 6 1 concentration liquids with a Content of 65 pounds of nitric acid and 3 * 2 l of washing liquid s consist of a previous experiment "The reaction ^{temperature is kept at 40 0} C for 48 hours" The crystal slurry obtained is removed.

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sucked and then washed with 3 1 70% fresh MO ^, which washing liquid (3 _f 2 l) and moist crystals results in ₀

The wet cyclopentane tetracarboxylic acid-i-cis, 2-cie, 3 ~ cis, 4-cis is then in a rotary dryer under a Yakuum of 16 mm Hg at a temperature dee oil bath of 70 ⁰ C dried to give 1.5 kg (yield equal to 82 %>) of the tetracarboxylic acid, which is identified by its infrared spectrum, the melting point and by thin layer chromatography, and contains less than 300 ppm nitrogen in the elemental analysis.

The mother liquors obtained in Abnutsehen (6.7 1) (20 mm Hg) was concentrated by distillation under reduced pressure to give the Waeeerbadtemperatur not exceeding 80 ⁰ C ^ yielding 1.1 1 of acidified water (3) and 5.6 1 concentrated liquid results (which is for example returned to the circuit using the following experiment) »

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1.48 kg cyclopentanetetracarboxylic acid-i-cie, 2-cis, 3-cis, 4-cis, with 300 ppm nitrogen, are mixed with 1.34 kg acetic acid residue, which is kept at 110 ⁰ O, with vigorous stirring. After the addition has ended, the mixture is stirred for one hour. After cooling, the crystals are suction filtered and washed with acetic acid (400 ml).

The crystals are dried in a rotary evaporator "which gives 1.2 kg (yield equal to 95%) of Oyolopentanetetraoarbon" saturate-1-cis, 2-cis, 3-cis, 4-cie-dianhydride, because it is dry and white and at 215 up to 216 ⁰ C eohmilat (in the capillary tube) and a nitrogen content of less than 100 ppm «

The clarification of the acetic acid liquids of light yellow color (mother liquors and washing liquidsa) gives 1670 Iu. Acetic acid without nitrogen ($> If <£ 100 ppi) and 35 g of residue containing 1.3 $> nitrogen.

Example 3

To 4 »5 1 of the aqueous, with CycIopentanetetracarbonsäure-

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1-oiSj 2-ois, 3-cis, 4 * -cis saturated solution, which is prepared as described in Example 1, is added 2 kg of cyclopentanetetracarboxylic acid-i-cis, 2-ois, 3-ois, 4 » Ice that is produced in the same way and contains 300 ppm of nitrogen.Hach dissolving at 7O ⁰ C, crystallization by cooling to 15 ⁰ G, removing and washing with a saturated solution of pure and uncrystallized cyolopentanetetracarboxylic acid-1-cis, 2-cis, 3-ois, 4-ice, staiamtj from a previous operation, and drying in a rotary dryer gives 1.7 kg of recrystallized cyclopentanetetracarboxylic acid 1-cis »2-cis, 3-cis, 4-cis, which contains less than 100 ppm nitrogen contains, and allows very little colored esters to be obtained.

One then proceeds by subtracting 0.4 l from the mother liquors from the crystallization and returning them to the stage of concentration of the mother liquors from nitric acid oxidation, while the remainder (3 _and 6 l) is washed with wash water (0.91 l). is added and returned to the stage of Umkrietallieation.

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The method of the invention has - as eohon explained at the beginning - Various advantages compared to the known working methods

While even with the known method of working, which is based on the cleavage of the double bond with 90 # nitric acid, a very highly impure product is formed, which is 10 $> soluble in ice cream, while the actual solubility is only 3 #, and this is impossible through Crystallization in water can be purified and cannot be converted into the anhydride in any way with acetic anhydride, because the anhydride obtained is completely unsuitable for the use for which it is intended, for example the hardening of epoxy resins ^ and the product obtained according to the information from Even though it can be purified by washing with aqueous acetic acid, but the purified product also gives an anhydride with only slightly better coloration, the process of the invention allows immediately and without subsequent purification with a yield of about $ 80 starting from endomethylene-1 , 2,3,6-tetrahydrophthalic acid or the corresponding anhydride is a cyclopentane tetraca rboxylic acid

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1 — ice, 2-cie, 3-cis, 4-cis, which contains virtually no nitrogen (less than 500 ppm) and which is practically insoluble in glacial acetic acid (less than 3 #) »which is white, straight to the Anhydride formation can be used thermally or with acetic anhydride, results in a white dianhydride which can be used directly, for example as a hardener for epoxy resins, no longer contains any detectable nitrogen (less than 100 ppm) and can be esterified to almost uncolored esters, and the is finally completely recrystallizable in water according to the procedure described above. The resulting recrystallized acid has no nitrogen (less than 100 ppm) and can be esterified directly.

The good quality of the product, which is known to be difficult to achieve using nitric acid oxidation methods is, however, absolutely necessary for normal uses of the product, such as for esters, polyesters, imides and polyimides and as hardeners for epoxy resins.

With the specified process conditions, a reaction time of more than 12 hours, the molar Ratio of nitric acid to endomethylenetetrahydro-

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phthalic acid or phthalic anhydride must be increased for more than 10 hours, the reaction temperature is to be expected as low as possible, the crystals separated from the mother liquors are washed with 70% nitric acid from the trade. Bs has been found that this solvent let better and that liberal · solves the minimum Cyolopentantetracarbonsäure ..

Moreover, this nitric acid can later be used as a new one Oxydationsbeschiokung can be used.

It is quite unexpected that the Oyclopentantotraoexbonaäureri -cla, 2-cie, 3-cia, 4 "oia dl-nitric acid" can be removed from the oyclopentantotraoexbonaäureri-cla, 2-cie, 3-cia, 4 "oia dl" nitric acid "for use" by adding under Vacuum at a temperature of up to 8O ⁰ C in the moving bed dries · There is no combustion whatsoever »

It is also unexpected that the reaction mother liquors, after the crystals have been separated off, can be distilled and thus brought to the nitric acid content required for recycling without any combustion of the organic products they contain.

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Claims (1)

/ f3 PATEHTANSPRi) OHE: 1ο Process for the production of cyclopentane tra- earboxylic acid 1-cis, 2-cis, 3-oiss »4-cis and its dianhydride, characterized in that the satire is satire by nitric acid oxidation of 3» 6-endomethylene-1,2,5t6-tetrahydroph thai or - phthalic anhydride with a reaction time of more than 12 hours and between 24 and 48 hours, a reaction temperature between 30 and 60 ° C _f preferably between. 40 and 45 ⁰ C, and a nitric acid concentration between 60 and 75 %, preferably 65 and 70 #, with the molar ratio between nitric acid and 3,6-EndoHätbylea-1,2,3 _t 6 ~ tetrahydrophthalic acid or between 10 and 20 and preferably between. 10 and 15, the crystals of cyclopentanetetraoarboxylic acid are separated from the remaining mother liquors , washed with fresh nitric acid at a concentration between 50 and 75%, preferably between 65 and 70 °, preferably the nitric acid used for washing to oxidize a new amount of 3 _tons 6-endomethylene-1,2,3,6-tetrahydrophthalic acid or anhydride is used, which returns the mother liquor remaining in the oxidation of nitric acid to the stage of oxidation of nitric acid, after OFTIGlNAl 109887/1824 ^NAL 17934U the her-nitric acid content by Abdestillier s of water under reduced bridging, preferably below 25 in Hg, wherein the bath tempera door or the temperature of Heiamediusis below 80 ⁰ C remains is reinstated, and that überfuhrt optionally the Cyolopentantetraoarbonsäure obtained in the dianhydride by subjecting it to the action of acetic anhydride at 100 to 140 ⁰ O, preferably 110 to 120 ⁰ O, the molar ratio between acetic anhydride and cyclopentanetetraoarboxylic acid between 2 and 4 "preferably" between 2 and 3 and in particular "between 2 and 2 , 2 lies, 2ο method according to claim 1, characterized in that that the cyolopentanetetracarboxylic acid can be obtained by IiBleren cleanses starting from its aqueous lorning. 3 · Method according to claim 2, characterized in that » which comprises carrying out recrystallization by leads back to the mother liquors of the Umkrietallisation in the circuit, after having peeled off one Kengenanteil 1-25 i> " 4. The method according to claim 1, characterized in that it is characterized _by 70% nitric acid-coated Oyolopmtentetrmoarbonslur · the Smlpetersture by Srvtrscn «on vapors up to 80 ⁰ O under Takmai in a moving bed. 109887/1824