DE2100391B2 - - Google Patents

Description

where R

a) 4,4'-diphenylene, 3,3'-dimethyl-4,4'-diphenylene, 4,4'-diphenylene oxide _T 4,4'-diphenylene methane, 4,4'-diphenylene sulfone;

b) the group - CH = NR ¹¹ —N- = CH—, in which R "p-phenylene, m-phenylene, 4,4'-diphenylene, 3,3'-diphenylene, 3,3'-dimethyl-4, 4'-diphenylene, 3,3'-dimethoxy-4,4'-diphenylene, 4,4'-diphenylene oxide, 4,4'-diphenylenemethane, 4,4'-diphenylenesu'f «-> n, 4,4- !> phenylene sulfide, 1,4-naphthylene, 1,5-naphthylene, 2,6-naphthylene, 2,7-naphthylene or 1,4-an ^{11 is} TyIeU;

uie group

OCH,

-CH

OCH,

OCH,

OCH,

CH-

where R '

The present invention relates to tetracarboxylic acid dianhydrides and procedures for their manufacture

^S "cMese class of organic compounds is currently gaining more and more importance, since the named anhydrides are widely used as starting monomers for the synthesis of heterocyclic

see polymers, polyimides, and polyimidazopyrrolones reach. The polymers of these types have excellent thermal stability due to excellent physico-chemical and mechanical properties is accompanied.

The aim of the present invention is synthesis before. -ornatic tetracarboxylic dianhydrides, the as monomers for the production of thermostable Polymer can serve that makes it possible Structure of the products without significant changes

to change the process of their manufacture. ,. , " _C

In accordance with the present invention, said object is achieved through development a new class of aromatic tracar-

acidic anhydrides, characterized by the general

my foiliiv.1

R ^1V

IV

40

45

means in which R ^IV H, OH. = O means;

d) the group _{—CH 2} OCC-R "- COOCH ₂ -, in which R ^{v is} p-phenylene, m-phenylene, 4,4'-diphenylene. Means 1,4-naphthylene, 1,5-naphthylene, 2,6-naphthylene, 2,7-naphthylene; and R ¹ denotes a hydrogen atom, a phenyl and naphthyl radical, and R ¹ denotes a phenyl or naphthyl radical when R denotes a valence stroke. c) the group

2. Process for the preparation of the compounds of claim 1, characterized in that one bis-adducts obtained after the Diels-Alder reaction of maleic anhydride and bis-furan compounds · Have been obtained and by the general formula

O O

where R

a) 4,4'-diphenylene, 3,3'-dimethyl-4,4'-diphenylene, 4,4'-diphenylene oxide, 4,4'-diphenylene methane, 4,4'-diphenylene sulfone;

b) the group -CH ^ N-R "-N = CH -, wherein R "p-phenylene, m-phenylene, 4,4'-diphenylene, 3,3'-diphenylene, 3,3'-dimethyl-4,4'-diphenylene, 3,3'-dimethoxy 4,4'-diphenylene, 4,4'-diphenylene oxide, 4,4'-diphenylene methane, 4,4'-diphenylene sulfone 4,4'-diphenylene sulfide, 1,4-naphthylene, 1,5-naphthylene, 2,6-naphthylene, 2,7-naphthylene or 1,4-anthrylene means;

OCH ₂

-CH

R "

OCH ₂

OCH,

OCH,

CH-

O = -

where R "

i J -r ^iv

are characterized in which R and R ^{1 have} the abovementioned meanings, in the presence of acidic R ^{| V}

denotes wherein R ^{lv denotes} H. OH, == O;

d) the group -CH ₂ OCO-R ^V -COOCH ₂ - which, suspended polymers are based on the above dianhydrides ert'orin R ^v p-phenylene, m-phenylene, 4,4'-diphenylene of particular interest, 4-naphthylene, 1,5-maphthylene, 2,6-naphthylene, the following points:, 7-naphthylene means;

R ¹ denotes a hydrogen atom, a phenyl or naphyl radical, and R ¹ denotes a phenyl or naphhyl radical when R denotes a valence stroke.

In terms of the usefulness of the properties

O =

O VCH = NV O> -N = CH- < O V \ O

ν ο

O V- CH ₂ OOC - <O Χ Ο V- COOCH ₂ - <O

o = <

= o

0 ^ _x y = O O

<^ o \ -CH,

OOC

CH ₂ OOC-Z ^ V COOCH ₂ - \ O

ο - _o = <> = o

The synthesis of the aromatic tetracarboxylic acid dianhydrides according to the invention consists in dehydration of the bis-adducts formed after the Diels-Alder reaction between the maleic anhydride and clen bis-furan compounds can be obtained and represented by the general formula

45

; = O

are characterized in which R and R 'are those in claim 1 <; o have given meaning.

Dehydration occurs under the action of acidic agents, namely gaseous hydrogen chloride and hydrogen bromide, concentrated hydrochloric acid, hydrobromic acid, sulfuric acid or polyphosphoric acid c at a temperature of -30 to +100 "C for at least 30 minutes in glacial acetic acid, more concentrated Sulfuric acid or polyphosphoric acid carried out as a solvent.

The choice of DchydratUionsbedingungcn is' ₀ determined by the used acidic Mi'tel.

When using gaseous agents, those heated to a temperature of 80 to 100 C are clinched Solution of said bis-adduct in Hisessiti, Hydrogen chloride or bio hydrogen for at least 1 hour bubbly.

According to this method, the best yields are obtained when using bromine, free hydrogen bromide achieved at the boiling point of glacial acetic acid in 4 to 8 hours.

Dehydration with concentrated acids such as hydrochloric, hydrobromic, sulfuric acid is the Zugabc of said acids to the solution of the adduct in glacial acetic acid and heating the mixture at temperatures from 20 to 8O ⁰ C for at least one hour conducted, wherein the acidic agent in amounts is used which do not exceed 0.5 mol per 1 Liier reaction mixture.

The best results are achieved according to this method when using concentrated sulfuric acid at a temperature of 20 to 30 ^° C. in 1 to 12 hours, with 4 to 6 ml of sulfuric acid being required for each 1 liter of glacial acetic acid.

When using the concentrated sulfuric acid and polyphosphoric acid are the acidic reagents at the same time also solvents for the implementation the reaction.

Thus, adds the Ausgangsaddukl to the cooled to a temperature of -30 to +10 ⁰ C and concentrated sulfuric acid are added häli the reaction mixture at these temperatures for at least 30 minutes. The concentration of the bis adduct in the sulfuric acid must not exceed 10 percent by weight.

In the polyphosphoric acid the starting bis adduct dehydrated at temperatures of 10 to 50 "C for at least 10 hours, the concentration of the bis adduct in the polyphosphoric acid must not exceed 30 percent by weight.

A particularly complete dehydration of the bis adducts by the two last-mentioned methods is at a concentration of the starting-to-

Adduct in the acidic agents mentioned of at most 3 to 5 percent by weight at a temperature of -10 to 0 ^° C. when using sulfuric acid and 20 to 30 ^° C. when using polyphosphoric acid.

According to the best variants of the methods listed above, the yield of aromatic Tetracarboxylic dianhydrides 50 to 85%.

It should be noted that the preparation of the invention Dianhydrides, in a very high yield, ι ο in acidic dehydration of bis-adducts, the acetal or ester bonds or Groupings of boat bases contain, surprising, because it is known that these structures against sour mean! are very sensitive.

All of the starting-to-adducts mentioned are new. The method for their synthesis sees the Diels-Alder reaction between at least two equivalents of maleic anhydride and one equivalent of bis-furan compound at a temperature of 0 to 100 ° C for at least 1 hour in benzene. Acetone, acetylacetone, tetrahydrofuran, cyclohexane or ethyl acetate as a solvent.

The highest yields (70 to 90%) of bis adducts are achieved when using three equivalents of maleic anhydride each one equivalent of the bis-furan compound at a temperature of 20 to 60 ° C for at least 4 hours in tetrahydrofuran as solvent

The reaction of the formation of the starting bis-adducts mentioned proceeds according to the following scheme:

RR ¹

(J

_r JI

O Λ «j.
^Χ Ο ⁷ + 21
1 - O
ι R ■ - - R ¹ ο O O- (J R ¹ - ^; ν ") ^ (j = -.

35

40

45

According to the invention, the bis-adducts of the Diels-Alder reaction between maleic anhydride and the following bis-furan compounds are used as starting compounds: bis- (5-R'-2-furyl) -arylenec. N, N'-bis (5-R'-furfurylidene) -diaminoarylene. 2.2'-. 5.5'-tetraphenyl-p'-difuryl. bis-furfuryl esters of aromatic dicarboxylic acids such as terephthalic isophthalic. 4,4'-diphenyldicarbon, 1.4-. 1,5-, 2.6- and 2.7-naph- ^ thalinedicarboxylic acid as well as compounds containing spirane groupings such as 3.9-bis- (5-R'-2-FuryI) -2.4.8.10-tetraoxaspiro / 5.5 undekane. 3.1 l-bis- (5-R'-2 - furyl) - 15 - R ^lv - 2.4.10.12 - tetraoxadispiro 5.1, 5.3 / hexadecane. 3.1 l-bis- (5-R ^I -2-furyl) -7-R ^lv -2.4.I0, ^ -tetraoxadispiro / SlS ^ / pentadekane. where R ^{1 is} a hydrogen atom, a phenyl or naphthyl radical and R ^IV —H. Is OH or = 0.

The bis- (5-R'-2-furyl) -arylenes were obtained by decomposition of the aromatic bis-diazo compounds according to f, ₅ Gomberg-Bachman in the medium of 5-R'-furan, where R ^{1 has} the meaning given in claim 1 . obtain.

The N.N'-bis-iS-R'-furfurylidenj-diaminoarylencs are condensation products of the corresponding aromatic diamines with 5-R'-furfural, where R ^{1 has} the meaning given in claim I.

By transesterification of the aromatic dicarboxylic acid methyl or -äthylestc with furfuryl alcohol, corresponding bis-furfuryl esters were obtained.

The bis-furan compounds, which one? Containing spirane groups, in the reaction of pentaerythritol or corresponding tetramethylolcyclohexane or tetramethylolcyclopentane derivatives with 5-R'-hurfurol. where R ^{1 has} the meaning given in the claim. obtained in the presence of anhydrous zinc chloride.

The aromatic tetracarboxylic acid dianhydrides according to the invention are used essentially as monomers for the synthesis of heterocyclic theimostable Polymers belonging to the classes of polyimides and polyimidazopyrrolones. The education these polymers see implementation of the aromatic dianhydrides mentioned with aromatic diamines for the production of polyimides and with ortho, ortho- or peri. peri-tetramines for making of polyimidazopvrrolones.

The polymers obtained on the basis of the dianhydrides according to the invention have a high thermal value. thenriooxydati * ^; e and resistance to ablation. For example, the temperature at which the polymer begins to lose weight in the presence of oxygen is in a range from 380 to 560 ° C., depending on the structure of the starting dianhydride.

All polymers are soluble in concentrated solutions of sulfuric acid or methanesulfonic acid and can be processed from solutions of these acids in a known manner to produce corresponding products will.

The well-known polyimides and polyimidazopyrrolones based on dianhydrides with 5-glicdrigen Anhydride rings are in known solvents insoluble and melts above the decomposition temperature. So you can only look for one Two-stage process in the form of the prepolymer are processed into end products that comprise a range of have fundamental disadvantages.

The use of dianhydrides in the Anhydride group-bearing nucleus contain phenyl or naphthyl substituents, made it possible at Maintaining a high thermal stability Pohimide and polyimidazopyrrolones obtained in cresols. Phenols and pyridines are soluble.

This property is also new for the polymer type and allow it. End products in a known manner via the solutions in organic solvents to obtain.

The dianhydrides according to the invention are also used as hardeners for increasing thermal stability the epoxy and novolak'-phenol-formaldehyde resin c. The use of these dianhydrides does it possible, the working temperature of the products made of epoxy resins by 50 to 80 C compared to the products from resins hardened by phthalic or maleic anhydride.

The examples given for the application of the dianhydrides according to the invention demonstrate their usefulness not limited. They can be used for the synthesis of carboxyl-containing polyesters in tetra-esters they are plasticizers door some types of polymers.

The invention is illustrated by the following examples, which also contain characteristic values of the products obtained are explained in more detail.

The synthesis of the dianhydride according to the invention aromatic acids is described in Examples 1 to 20. Additional information on the manufacture of the Starting materials are in Examples Λ to Q (synthesis of bis-adducts) and A 'to O'.

The aromatic tetraearboxylic acid dianhydrides according to the invention are used essentially as Monomers for the synthesis of heterocyclic thermally stable polymers belonging to the classes of polyimides and polyimidazopyrrolones. The education these polymers see implementation of the aromatic dianhydrides mentioned with aromatic diamines for the production of polyimides and with ortho- or pen-, peri-tetramines for the production of polyimidazopyrrolone.

The polymers obtained on the basis of the dianhydrides according to the invention have high thermal, thermo-oxidative and ablation resistance. For example, the temperature at which the polymer begins to lose weight in the presence of oxygen is in a range from 380 to 560 ° ^C. , depending on the structure of the starting dianhydride.

All polymers are soluble in concentrated sulfuric acid or methanesulfonic acid and can be made from Solutions of these acids are processed in a known manner to give corresponding products.

The well-known polyimides and polyimidazopyrrolones ; on the basis of dianhydrides with .V'.licdrigen Anhydride rings are not soluble in known solvents and melt above the decomposition temperature. So you can only sit after one Two-stage process in the form of the prepolymer End products are processed, which have a number of fundamental disadvantages.

The use of dianhydrides that · <η dem Anhydride group-bearing core ι-i ^ .. yl- or Naph thylsubbiituenien made it possible at Maintaining a honing thei mix stability polyimide and polyimidazopyrrolone obtained in Cresols. Phenols and pyridines are soluble.

This property is also new for the Poiymerentvp and it allows end products in a known manner via the solutions in organic solvents to obtain.

The Dianhydnde invention can also be used as curing agents for thermostability increase in f-.poxyd- and novolac "-Phenolformaldehydharze. The use of these dianhydrides makes it possible to the operating temperature of the products of epoxy resins by 50 to SO ⁰ C compared to the products made by phthalic or Maleic anhydride cured resins to boost.

The examples given for the application of the dianhydrides according to the invention demonstrate their usefulness not limited. They can be used for the synthesis of carboxyl-containing polyesters. Convicted in tetra-esters they are plasticizers for some types of polymers.

The invention is illustrated by the following examples, which also contain characteristic values of the products obtained are explained in more detail.

The synthesis of the dianhydrides of aromatic acids according to the invention is described in Examples 1 to 20. Additional information on the preparation of the starting material can be found in Examples A. to Q (synthesis of bis adducts) and A 'to O' (synthesis in! ^ furan compounds).

Example I.

1.75 mmol of dianhydride of N, N'-his- (2,3-dicarboxy-1,4-oxo-5-cyclohexenylmethylene) benzidine it was dissolved in 70 ml of glacial acetic acid and a stream of dry hydrogen bromide purified from bromine was passed through it a. The reaction mixture was heated slowly to

ίο to boiling and kept at the boiling point during 4 to 5 hours, then stopped the supply of hydrogen bromide and distilled the acetic acid under vacuum away. The residue was recrystallized from glacial acetic acid and co-precipitated from 10% strength solution in KOH

lÜ'Voiger HCl, washed with water and carried out in dianhydride with heating to a temperature of 120 "C for 6 to 8 hours. The yield on Dianhydride of N, N'-bis (2,3-Dicarboxybenzylidcn) benzidine (it corresponds to the general formula Claim 1 with

R-CH N- R "N CH.

R ¹ H: R "= 4,4'-Diphenylcn) was 73%. Acid number: rounds 448, the calculated 448.% Found: C 71.8: H 3.24; N 5.71; calculated for C", l Ι ,,, Ν, ί J ₁ , in%. C 72.0; H 3.20; N 5.60.

Example 2

0.78 mmol of dianhuiride des N.N'-bis-uV.-iVarboxy-1,4-oxo-5-eyclohexylmelhylen) -toiidine! Add to a mixture of 60 ml of glacial acetic acid and 4 pints of concentrated sulfuric acid and then add it the reaction mixture for 56 hours at r eim.-temperature \ un 20 C ^r \ n glacial acetic now damplte. a, washed the residue with water and eiliu ^ after the treatment of the product according to the ν nah mi of Example 1 80% dianhydride des NN -hi-i -J-dicarboxyben / ylidcnj-toluidine (it corresponds to ^ a 'Huemeine formula according to claim 1 with

R -CH N R "N ClI:

R '11. R "3.3'-DimelhyI-4.4'-diphcnylen)

Acid number: found 427. calculated 424 found ". ·: C 72.4; H 3.83; N 5.18: K.echnet for (\, l K" N, (\ in "·": C 72.7; H 3.79; N 5.2S.

Example 3

0.76 mmol of dianhydride des N.N'-bis- (2.3-dicarboxy - 1.4 - oxo - 5 - cyclohexenylmethylene) - diammodi-

phenyloxids was dissolved in 70 ml of polyphosphoric lure (Content of phosphoric anhydride 74.8%) aiii and stirred for 60 hours at a temperature of 20 C. The reaction mixture was poured into water and the rainfall by example! treated

dell. 56% dianhydride of N.N'-bis- (2.3-dicarboxybenzylider!) diaminodiphcnylomis Ies corresponds to the general formula according to claim 1 with

R = -CH = N-R "-N Cl-I-;

R - H, R "= 4,4'-diphenylene oxide).

Acid number: found 428, calculated 434 Found%: C 70.1; H 3.27; N 5.26; Calculated for C, _O I1, ₍ , N, O ₇ in%: C 69.9; H 3.10: N 5.42.

Example 4

10 mmol of dianhydride des N, N'-bis- (2,3-dicarboxy-1,4 - oxo - 5 - cyclohexenylmethylene) - ρ - phenylenedi-

emins was added in portions to 250 ml more concentrated Sulfuric acid, cooled to a temperature of -10 "C. After the addition was complete, the mixture was stirred Han the mixture for one hour and pour the solution onto Bis. The precipitate was treated li according to Example 1 and received 82% dianhydride of K, N '- bis - (2,3 - dicarboxybcnzylidene) - ρ - phenylenediamines (It corresponds to the general formula according to claim 1 with

R CH N --R "-N CH -;

IN; R "p-phenylene).

Acid Number: found 530, calculated 528. Found %: C 67.8; H 2.99; N 6.73: calculated door C ₂₄ HpN ₂ O ₆ fei%: C67.8; H 2.83; N 6.60.

Example 5

2 mmol (1.24 g) dianhydride des N, N'-bis- (4-phenyl-2.3 - dicarboxy - 1,4 - oxo - 5 - cyclohexenylmelhylene) -0-phynylcndiamines was dissolved in 170 ml of glacial acetic acid, 21 ml of concentrated hydrochloric acid were added and the mixture was heated ♦ For 48 hours at a temperature of 100 ° C. f) the solvent was removed in vacuo and the product was recrystallized from acetonitrile. One got 72% (0.825 g) dianhydride of N, N'-bis- (4-phenyl, 3-dicarboxybenzylidene) -p-phenylcondiamine (It corresponds to the general formula according to claim 1 with

R -CH N R "N- (H ~;

R 'phenyl; R "p-PhenyicnS, does not melt at 300 ⁰ C.

Acid number 372 (calculated 389). Found%: C 74.5; H 3.56; N ^c : 2; calculated for C _J6 H, ₀ N, O _{(in%: r,} C 75 0; H 3.48; N 4.87.

Example (>

2 mmol (1.37 g) of dianhydride of N.N'-bis- (4-phenyl-2,3-dicarboxy-1,4-oxo-5-cyclohexylmethylmethylcn) -ben / idine were dissolved in 180 ml of glacial acetic acid, f Drops of concentrated sulfuric acid were added and the reaction mixture was stirred for 56 hours at a temperature of 20 ^° C. The product was poured into 0.5 l of water and the precipitate was filtered off. washed with water and recrystallized from acetonitrile. 64% (0.855 g) of dianhydride of NN -bis- (4-phenyl-2,3-dicarboxybcnzylidene) benzidine were obtained (it corresponds to the uncommon formula according to claim 1 with

CH N- R "N-CH;

Example 8

R '- = phenyl. R "4,4'-Diphenyien): does not melt up to 300 ^c C.

Acid number 342 (calculated 348). Found%: C 77.0; H 3.52; N 4.47; calculated door C ₄₂ H 1 N ₁ O ₆ in%: C 77.2; H 3.73; N 4.35.

Example 7

2 mmol (0.944 g) of dianhydride of 4.4'-di- (2.3-dicarboxy-! ^ Oxo-S-cyclohexenylJ-diphenyls were treated according to Example 4 and obtained (0.42 g) 47% p-quaterphenyl-2.2 "', 3,3 "' - tetracarboxylic dianhydride (it corresponds to the general formula according to claim 1 with fc = 4,4'-diphenylene; R '= H). Melting point> 300 ^D C. _6s

Acid number: found 492, calculated 503. Found * '/ o: C 75.0; H 3.51; Calculated for C ₂₈ H ₁₄ O ₆ in%: C 75.3; H 3.14.

2 nmoles (0.944 g) of 4,4'-di- (2,3-dicarboxy-1,4-oxo-5-cyclohexenyl) diphenyl dianhydride treated according to Example 1 and obtained 53% (0.47 g) of p-quaterphenyl-2.2 '", 3.3'" - tetracarboxylic acid dianhydride.

Example 9

ίο 2 mmol (0.944 g) dianhydride of 4,4'-di- (2,3-dicarboxy-1,4-5-oxocyclohexenyl) -diphenyl treated according to Example 2 and obtained 63% (0.696 g) of p-quaterphenyl-2,2 '", 3,3'" - tetracarboxylic acid dianhydride.

is example 10

5 mmol (2.79 g) of dianhydride of 1,4-di (4-phenyl-2,3-dicarboxy-1,4-oxo-5-cyclohexenyl) benzene was dissolved in 400 ml of glacial acetic acid and passed at a temperature of 100 ⁰ C gaseous HBr for 12 hours. The solvent was removed in vacuo and the product was recrystallized from acetylacetone. 78% (2.04 g) of 4,4 "-diphenyl-p-tert-phenyl-2,2", 3,3 "-tetracarboxylic acid dianhydride were obtained (it corresponds to the general formula according to claim 1 with R p-phenylene; R '= phenyl. Melting point> 300 "C.

Acid number 432 (calculated 429). Found% C 77.8; H 3.58; Calculated for C ₃₄ H ₁₈ O ,, in%: C 78.2; H 3.45.

Example 11

2 mmol (1,268 g) dianhydride of 4.4'-di- (4-phenyl-2,3-dicarboxy-1,4-oxo-5-cyclohexynyl) -diphynyl in 40 ml of ISd "iiiger polyphosphoric acid was stirred during 5 days at a temperature of 20''C. The solution was poured into water, the precipitate filtered off, washed with water and recrystallized from acetylacetone. 51% (0.603 g) were obtained 4.4 '"- Diphenyl - ρ - quaterphenyl - 2.2'". 3.3 '"- tetracarboxylic dianhydride (It corresponds to the general formula according to claim 1 with R 4,4'-diphenyl; R 'phenyl).

Melting point> 3tH) C. Acid number 384 (calculated 375). Found "": C 79.2: H 3.82; calculated for ^ 4oH _2; O _h in 'VCX (U; Π 3.68.

Example 12

2 mmol (0.096 g) dianhydride des 3,9-bis- (2,3-dicarboxy - 1.4 - oxo - 5 - cyclohexenyl) - 2.4.X.I0 - tctraoxaspiro 5.5 undecans in 100 ml of glacial acetic acid were treated with dry hydrogen chloride at a temperature of KX) C for 16 hours. The I.ösuni was precipitated in ether and the product from Mclh.inol iimkrisiallisicrt with activated charcoal. One received 51 ". (0.454 g) dianhydride des 3,9-bis- (2,3-dicarboxyphc

nyl) -2,4.8, lO-tctraoxaspiro / S ^ / undckans it corresponds of the general formula according to claim 1 with

OCH ₁

R = -CH

OCH,

OCH,

OCH ₇

CH

R = H; R "'= C

Melting point 284 to 286 C. Acid number 490 (calculated 495). Found%: C 61.3; H 3.51: Calculated for C ₂₃ H ₁₆ O ₁₀ in%: C 61.0; H 3.40.

Example 13

2 mmoles (1.12 g) of dianhydride des 3.1 l-bis (2.3-dicarboxy-1,4-oxo-5 -cyclohexenyl) - 2,4,10.12- letraoxadispiro / 5.1,5,3 / hcxadekans it was heated in 75 ml of 16% polyphosphoric acid for 4 days a temperature of 20 ° C. The solution was poured into water, the precipitate was washed and obtained after Recrystallization from ethanol 42% (0.438 g) dianhydride of the 3.1 l-bis (2,3-dicarboxyphenyl) -2,4,10.12-content 72% (0.7 g) dianhydride of di- (2,3-dicarboxyphenylj-terephthalate (it corresponds to the general Formula according to claim 1 with

R = —CH ₂ OOC-R ^v - COOCH ₂ -

R '= - H; R ^v = p-phenylene).

Melting point 216 to 217 ° C. Acid number 457 (calculated 460). Found%: C 64.2; H 3.18; Calculated for C _2n H ₁₄ O ₁₀ in%: C 64.1; H 2.98.

Example 16

lraoxac! äspiro / 5, l, 5,3 / hexadecar. 3
• General formula according to claim 1 with
OCH ₂ OCH,

To 2 mmol (1.04 g) of dianhydride of di- (2,3-dicarboxy-M-oxo-S-cyclohexenyl herephthalate in 130 ml of glacial acetic acid, 4 drops of concentrated sulfuric acid, equivalent to the acidic acid, were added.> Stirred for 62 hours a temperature of 20 ° C. The product was precipitated in water, washed on a filter and obtained after recrystallization from ethyl acetate 80% Ό.778 g) dianhydride of di- (2,3-dicarboxyphenyi) -terephtha-

lats. ... ,

Example 17

■ \

CJ!

C) CH,

-R *: R ^w = Hi.

25th

Melting point 261-262 ° C. Acid 430 (calculated 430). Found%: C 64.62: H 4.74; calculate! for C ₂₈ H ₂₄ O ₁₀ in%: C 64.6; H 4.63.

Example 14

To 2 mmol (1.28 g) of dianhydride of 3.9-bis- (4-phenyl-2,3-dicarboxy-1.4-oxo-5-cyclohexeny!) - 2.4. $ .10-telraoxaspiro / 5,5 / undekans in 100 ml glacial acetic acid one added 4 drops of concentrated sulfuric acid, one held for 7 days at a temperature of 20 "C, removed the solvent under vacuum and i" the product recrystallized from acetone. 71.8% (0.86 g) of dianhydride of 3.9-bis (4-phenyl-2,3 - dicarboxyphenyl) - 2,4.8,10 - tetraoxaspiro 5.5 un-

decans

it corresponds to the general formula

Claim 1 with

OCH ₂

OCH,

R = -CH

_R , "

CH

OCH,

OCH,

R = phenyl; R "= C

55

Melting point 212 ° C. Acid number 370 (calculated 372). Found%: C 69.2; H 4.13; calculated door C ₃ , H, ₄ O ₁₀ in%: C 69.6; H 3.98.

Example 15

2 mmol (1.04 g) of dianhydride of di- (2,3-dicarboxyl.4-oxo-5-cyclohexenyl) -tercphthalate in 170 ml of ice-cessig was treated with a stream of dry HO at a temperature of 100 ^° C. during ^ Hours. The solvent was removed in vacuo, the product was recrystallized from ethyl acetate and the 2 mmol (1.04 g) dianhydride of di- (2,3-dicarboxyl, 4-oxo-5-cyclohexenyl) isophthalate in 40 ml of polyphosphoric acid was stirred for 72 hours at a temperature of 30 to 40 "C. The product was precipitated in water, washed with water until a neutral reaction was achieved and recrystallized from ether acetate. 54% (0.525 g) of dianhydride of the di were obtained - (2.3-dicarboxyphcnyl) -isophthalate (it corresponds to the general formula according to claim 1 with

R-CH ₂ OOC R ^v COOCH ₂

R 'H; R ^v - = m-phenylene).

Melting point 187-189 ° C. Acid number 446 (calculated 460). Found%: C 63.84; H 3.12; Calculated for C ₂₆ H ₁₄ O ₁₀ in%: f '64.1; H 2.98.

Example 18

2 mmol (1.04 g) of dianhydride of di- (2,3-dicarboxyl, 4-oxo-5-cyclohexenyl) isophthalate were treated as in Example 4 and 76% (0.738 g) of dianhydride of di- (2,3-dicarboxyphenyl) were obtained ) isophthalate.
Example 19

1.68 mmol (1 g) of di- (2,3-dicarboxy-1,4-oxo-5-cyclohexeny 1) 4,4'-diphenyldicarboxylate was treated according to Example 2 and 68% (0.638 g) dianhydride were obtained di- (2,3-dicarboxyphenyl-4,4'-di-phenyldicarboxylate (It corresponds to the general formula according to claim 1 with

R -CH ₂ OOC R ^v COOCH ₂

R = H; R ^v = 4,4-diphenylene).

Melting point 218 to 219 ° C. Acid number 392 (calculated 399). Found%: C 68.3; H 3.40; Calculated for C ₃₂ H ₁₈ O ₁₀ in%: C 68.3; H 3.21.

Example 20

2 mmol (1,268 g) 3,3 ', 4,4'-dianhydride of 2.2'. 5.5'-Tetraphenyl-3,3 ', 4,4'-tetracarboxy-1.1'-dicyclohexene-1 was treated as in Example 1 and, after recrystallization from acetylacetone, 51% (0.603 g) 2.2' ₍ 5.5'-tetraphenyl-diphenyl -3.3'.4.4'-tetracarboxylic dianhydride (it corresponds to the general formula according to claim 1, where R is absent, R '= Ph).

Melting point 284 to 286 ° C. Acid number 362 (calculated 375). Found%: C 80.3; H 3.84; Calculated for C ₄₀ H ₁₂ O ₆ in%: C 80.3; H 3.68.

material

2 iOO

Production of the starting material

Example A 2mmol (0.572 g) 4 / _: '-bis- (a-FuryI) -dipheny!

and

10 mmol (0.98 g) maleic anhydride m 10 ir-1 tetrahydrofuran was heated for 8 hours at a temperature of 40 to 60 ^° C. The reaction mixture was poured into excess ether, the precipitate was filtered off and dried under vacuum at a temperature of 20 ^c C and crystallize from warm (40 to 6O ⁰ C) acetonitrile. 77% (0.74 g) of 4,4'-bis (2,3-dicarboxy-1,4-oxo-5-cyclohexenyl) diphenyl dianhydride were obtained. Zersetzunsspunkt -100 ⁰ C. Acid number: found 431, calculated 465. Found%: C 69.2; H 3.86: Calculated for C ₈ H ₁₈ O ₈ in%: C 69.7: H 3.74.

Example B lus of the organic layer of the reaction- -85 ° C. Found%: C 62.5; H 3.31; Calculated for C ₃₀ H ₂₀ O ₁₂ in%: C 62.9; H 3.49.

Example G

0.01 mol (2.92 g) of 3,9-bis- ( _(i -Furyi) -2,4,8,10-tetraoxaspiro / 5,5 / undckan was dissolved in 75 ml of tetrahydrofuran and then 0.04 mol (3.82 g) maleic anhydride. After 72 hours, the solution was precipitated with an excess of ether and, after filtration, 68% (4.5 g) dianhydride of 3.9-bis- (2,3-dicarboxy-1, 4 - oxo - 5 - cyclohexenyl) - 2,4, SJO-tetraoxyspiro / S ^ / undecans. Decomposition point ~ 85 ^D C. Acid number: found 462, calculated 460. Found%: C 56.4; H 4.15; calculated for C ₃ H ₂₀ O ₁₂ in%: C 56.6; H 4.10.

Example H

3 mmoles (0.875 g) 3,9-bis (α-furyl) -2,4,8,10-tetraoxaspiro / 5,5 / undecane and 6 mmol (0.568 g) maleic acid

After the decomposition of the diphenyl-4,4-bis- 20 anhydride in 50 ml of ether, the mixture was kept for 7 days

_j:: Ui; j_ / /\/\^r-*#_i._T* ■ 1 · ·. · 1 · · ..... τ ± ** r \ / ^ cu « _A fta ^ _α η Χ1ΐζ »/ ^ Ο» -_

diazonium chloride (product obtained from 0.025 mol of p-benzidinamine) in furan was treated with a solution of 2 g of maleic anhydride in 15 ml of tetrahydrofuran. After 12 hours heating was poured at 40 to 60 'C, the reaction mixture in excess of ¹ - gen ether, filtered off the precipitate dried under vacuum at a temperature of 20 C and recrystallized from warm (40 to 6O ⁰ C) of acetonitrile in order. 0.64 g of dianhydride des4,4'-bis- (2,3-dicarboxy-l ^ -oxo-S-cyclohexenyD-di-henvls.

Example C

0.01 mole (3.26 g) of terephthalic acid-bis-furfuryl, and 0.03 mol (2.96 g) of maleic anhydride was heated in 150 ml of tetrahydrofuran for 6 hours at a temperature of 8O ⁰ C. The solvent was removed under vacuum and obtained after recrystallization from warm (40 to 60'C) tetrahydrofuran dianhydride of di (2,3-dicarboxy-1,4-oxo-5-cyclohexenyl) terephthalate. Yield 67% (3.34 g). Decomposition point ~ 85 C. Acid number 432 (calculated 429). Found%: C 59.6; H 3.58; Calculated for C ₂₆ H ₁₈ O ₁₂ in%: C 59.8; H 3.45.

Example D

45 0.01 mole (3.26 g) bis-furfuryl isophthalate

and 0.03 mol (2.96 g) of maleic anhydride were treated according to Example C and 54% (2.82 g) of dianhydride of di- (2,3-dicarboxy-1,4-oxo-5-cyclohexenyl) isophthalate were obtained . Decomposition point ~ 80'C. Acid number 426 (calculated 429). Found%: C 59.8; H 3.68; Calculated for C ₂₆ H ₁₈ O ₁₂ in%: C 59.8; H \ 45.

Example E.

From 0.01 mol (4.01 g) 4,4'-diphenyldicarboxylic acid bis-furfurate and 0.03 mol (2.96 g) maleic anhydride, 69% dianhydride of di- (2,3-dicarboxy) was obtained according to Example C 1,4-oxo-5-cyclohexenyl) -4,4'-diphenylcarboxylate. Decomposition point - 75 ° C. Acid number 370 (calculated 375). Found%: C 63.9; _bo H 3.74; Calculated for C ₃₂ H ₂₂ O ₁₂ in%: C 64.2; H 3.68.

Example F

From 0.01 mol (3.76 g) 1,5-naphthalenedicarboxylic acid bis-furfuryl ester and 0.03 mol (2.96 g) maleic anhydride, 72% dianhydride of the di- (2,3-dicarboxy -1, 4 - oxo - 5 - cyclohexenyl) -1,5 - naphthalenedicarboxylate. Decomposition point at a temperature of 20 C. The precipitate was filtered off, dried in air and recrystallized from warm methanol. 74% (1.06 g) of dianhydride of 3,9-bis (2,3-dicarboxy-1,4-oxo-5-cyclohexenyl) -2,4,8,10-tetraoxaspiro / 5.5 / -undecane were obtained . Acid number: found 460, calculated 460. Found %: C 56.6: H 4.17; Calculated for C _2-1 H ₂₀ O ₁₂ in%: C 56.6; H 4.10.

Example I.

From 0.1 mol (36 g) 3.1 l-bis (a-furyl) -2,4,10,12-tetraoxaspiro / 5, l, 5.3 / hexadecane and 0.3 mol (29.4 g) Maleic anhydride was obtained according to Beispk. G 82% (45.6 g) dianhydride des 3, ll-bis- (2,3-dicarboxy-1,4-oxo-5-cyclohexenyl)-2,4,10,12-tetraoxadispiro / 5,1,5 , 3 / hexadecans. Decomposition point ~ 78 'C. Acid number 400 (calculated 402). Found%: C, 60.4; H 5.00; Calculated for C ₂₈ H ₂₈ O ₁₂ in%: C 60.4; H 5.03

Bei.riel J

From 0.01 mol (3.76 g) 3, ll-bis- (a-Fury!) - 15-oxy-2,4, 10,12-tetraoxadispiro / 5, l, 5.3 / hexadecane was obtained after Example G 74% (4.23 g) dianhydride of 3,11-bis- (2,3-dicarboxy -1,4-oxocyclohexen-5-yl) -15-oxy-2,4,10,12-tetraoxadispiro / 5, l, 5.3 / hexadecane. Decomposition point 8O ⁰ C. Acid number 393 (calculated 393). Found%: C 58.4; H 4.64; Calculated for C ₂₈ H ₂₈ O ₁₃ in%: C 58.7; H 4.89.

Example K

From 0.01 mol (3.74 g) 3,11-bis- (a-furyl 1-2,4,10,12-tctraoxadispiro / 5, l, 5,3 / hexadecan-15-one was obtained according to the example G 67% (3.82 g) 3, ll-bis- (2,3-dicarboxy-1,4 - oxo - 5 - cyclohexenyl) - 2.4,10,12 - ietraoxadi spiro / 5, l, 5.3 / -hexadecan-15-one. Decomposition point ~ 85 ° C. Acid number 380 (calculated 393). Found%: C 58.8; H 4.30; calculated for C ₂₈ H ₂₆ O ,, in%: C 58.9; H 4.54.

Example L

5 mmoles (2.46 g) N, N'-bis (5-phenylfurfurylidene) benzidine and 20 mmoles (1.96 g) maleic anhydride in 200 ml of tetrahydrofuran the mixture was stirred for 6 hours in an inert atmosphere at the boiling point of the solvent. The precipitate was filtered off and extracted with tetrahydrofuran during 48 hours (all operations in an inert atmosphere). 79% (2.72 g) of dianhydride of the N, N'-bis-

(4 - phenyl - 2,3 - dicarboxy - 1,4 - oxo - 5 - cydohexenylmethylene) benzidine. Decomposition point ~! 00 ° C. Acid number 317 (calculated 326). Found%: C 71.9; H 4.22; calculated door C ₄ , H, ₈ N, O ₈ in%: C 73.3; H 4.07; N 4.07.

Example M

SmMoI (2.08 g) N, N'-bis (5-pheny! Furfurylidene) -p-phenylenediamine and 20 mmol (1.96 g) maleic anhydride were treated according to Example L and 81% (2.48 g) were obtained Dianhydride of N.N'-bis- (4-phenyl-2,3-dicarboxy-1,4-oxo-5-cyclohexenylmethylene) -p-phenylenediamine. Decomposition point ~ 100 ^Ci C. Acid number 354 (calculated 366). Found: C 70.5: H 3.82: N 4.71; Calculated for C ₃₆ H ₂₄ N ₁ O ₈ in%: C 70.7; H 3.87; N 4.58.

Example N

2 mmol (0.724 g) 1,4-bis (5-phenyl-2-furyl) -benzene and 4 mmol (0.392 g) maleic anhydride were treated according to Example L and 62% (0.57 g) dianhydride of 1,4-di was obtained - (4-ph '* "yl-2,3-dicarboxy-1.4-ox (> 5-cyclohexenyl) -bene / ok. / Replacement point - 85 C. Acid number 392 (calculated 401). Found%: C 72.9 ; H 4.13; calculated for C ₃₄ 1., O ₈ in%: C ^- 73.16; H 3.94.

Example O

From 2 mmol (0.876 g) 4,4'-bis- (5-phenyl-2-furyl) -diphenyl and 4 mmol (0.392 g) maleic anhydride, according to Example L, 68% (0.66 g of dianhydride 3c of 4.4 '-bis- (4-phenyl ^ -dicarboxy-1 A-oxo-S-cyclo-!, exenyU-diphenyis. Decomposition point ^ 90 C. Acid number 350 (calculated 354). Found%: C 74.2; H 4.32; calculated for C ₄₀ H ₂₆ O _n in%: C 75.7; H 4.11.

B e 1 s ρ i e 1 P

2 mmol (0.888 g) of 3,9-bis- (5-I ⁵ henyl-2-furyl) -2.4, 8,10-tetraoxaspiro / 5.5 undecane and 2 mmol (0.196 g) of maleic anhydride in 100 * "! Ether it was kept at a temperature of 20 ° C. for 7 days. The precipitate was washed several times with ether and 92 "/" dianhydride of 4,4'-bis- (4-phenyl-2,3-dicarboxy-1,4-oxo-5 was obtained - cyclohexcnyl) - 3,3 ', 5,5' - tctraoxaspiro / 5.5 / -undekans. Decomposition point ~ 80C. Acid number 348 (calculated 350). Found%: C 65.6; H 4.40; calculated for C ₃₅ H ₂₈ O ₂ in% · ⁿ 65.7; H 4.38.

Example C-

From 2 mmol (0.876 g) 2,2 ', 5,3'-tetraphenyl-, i-difury! and 4 mmol (0.392 g) maleic anhydride were obtained according to Example L 78% (0.837 g) 3,3 ', 4,4'-oianhydride of 2,2', 5,5'-tetraphenyl-3,3 ', 4, 4'-tetracarboxy-1,1'-dicyclohxene-1. Decomposition point ~ 100 ° C. Acid number 350 (calculated 354). Found%: C 75.7; H 4.23; Calculated for C ₄₀ H ₂₆ O ₈ in%: C 75.7; H 4.11.

Example A '

To a solution of 0.025 mole (6.4 g) Bcnzidinhydrochlorid in 100 ml of water and 15 ml of 35% HCl, cooled with 25 g ice to a temperature of from ⁰ ° C, is added dropwise 35% aqueous solution of 0.05 Mo! Add (3.55 g) sodium nitrite. The cooled solution of diazonium salt which has been filtered off is slowly added to an intensely stirred emulsion of 200 ml of freshly distilled furan and 3 g of 5N NaOH solution. After stirring for 24 hours (after the first 5 hours at a temperature of 33 ° C.), the organic layer was separated off, the precipitate was extracted with furan (3 times 25 ml) and the solvent was removed from the combined furan fractions. Chromatography on neutral alumina in benzene gave 7.2% (0.51 e) 4,4'-bis - (. J-furyl) diphenyl. Melting point 104 to 106 ⁰ C. Found%: C 83.2; H 5.12; Calculated for C ₂₀ H ₁₄ O ₂ in%: C 83.9; H 4.89.

Example B '

To a solution of 0.05 mol (12.85 g) Benzidinhydrochlorid in 200 ml of water and 30 ml of 35% HCl, cooled with 100 g ice to a temperature before 0 ⁰ C, was added dropwise 0.1 mol (7.1 g) add sodium nitrite. 0.05 mol (14.5 g) of finely ground 2,5-naphthalenedisulfonic acid were added to the diazonium salt solution, and the precipitate was filtered off and dried in a vacuum desiccator over calcium chloride. 10.5 g of sodium acetate in 2.25 g of acetic anhydride were added dropwise to the suspension of diazonium salt in 200 ml of freshly distilled furan. After 48 to 56 hours of boiling with a reflux condenser, the organic layer was separated off, the precipitate was extracted with furan and, analogously to Example A, 12.6% (1.7 g) 4,4'-bis («- furyl) -diphenyl were obtained.

Example C "

0.1 mole (27.1 g) of 4,4-Diaminodiphenylmethanhydrochlorid Jiazotierte one and decomposed in an excess of 2-P ^K enylfvran after ^Ro ispielA '(with one exception, that in the case during the last 2 Stunder, the decomposition of the diazonium salt was carried out a temperature of 60 C ") melting point 132 16% was obtained (7.3 g) of 4,4-bis- (5-phenyl-2-furyl) diphenylmethane to 134 C. ^1% Found:.. C 88.8; H 5.68; calculated for C ₃₃ H ₂₄ O ₂ in%: C 89.5; H 5.43.

Example D '

0.1 mol (25.7 g) benzidine hydrochloride was diazotized and decomposed over stabilized bis-diazonium salt in an excess of 2-naphthylfuran (modification: during the last 2 hours the decomposition of the diazonium salt took place at a temperature of 80 to 95 C). 15% (8.07 g) of 4.4'-bis (5-Naphlhy1-2-furyl) diphenyl were obtained. Melting point 119 to 122'C. Found%: C 88.6; H 4.42; Calculated for C ₄₀ H ₂₆ O ₂ in%: C 89.1; H 4.83.

Example E '

A solution of 0.05 mole (12.84 g) benzidine hydrochloride in 170 ml of glacial acetic acid, 0.1 mol (12.1 g) of amyl nitrite was diazotized at a temperature of 10 "C. The diazonium salt was precipitated with ether and freshly distilled in 750 ml with vigorous stirring 2-phenylfuran with simultaneous addition of a solution of 7 g of anhydrous sodium acetate in 30 ml Acetic anhydride decomposes. The temperature was increased slowly to 33 ° C. After the evolution of nitrogen had ceased (about 6 to 8 hours) was distilled the excess of 2-phenylfuran under vacuum, dissolved the precipitate in benzene and obtained through Chromatography on neutral alumina 19.1% 4,4-bis- (5-phenyl-2-furyl) -diphenyl.

Example F '

0.3 mol (28.8 g) of furfural and 0.1 mol (20.4 g) of U ^ -Tetramelhylolcyclopcntan ^ -one was stirred with 0.7 g of anhydrous zinc chloride at the boiling point of furfural for 3 to 4 hours. When cooling down hardens the reaction mass. After chopping

and recrystallization from acetone gave 58% 3,11 - bis (2 - furyl) - 2,4,10,12 - tetraoxadispiro / 5,1,5,2 / pentadecan-7-one. Melting point 184 to 187 ° C. Found%: C 63.0: H 5.58; calculated door C ₁₉ H ₇₀ O ₇ in%: C 63.3; H 5.56.

Example G '

According to Example F ', from 0.1 mol of furfural, 0.03 mol of II ^ -Tetramethylolcyclohexan-S-one and 0.5 g of zinc chloride 67% 3.11 -bis- {2-Fuiyl) -2.4, l 0, 11-tetraoxadispiro / 5.1, 5.3 / hexadecan-15-one. Melting point 213-214 ° C. Found%: C 64.2: H 5.88; calculated door C ₂₀ H ₂₂ O ₇ in%: C 64.3; H 5.54.

Example H '

0.1 mol (17.5 g) 5-phenylfurfural and 0.03 Mc! (4.45 g) pentaerythritol is mixed with 0.5 g of anhydrous zinc chloride at a temperature of Ί35 ° C. for 4 hours. The precipitate was filtered off and, after recrystallization from acetone, 74% (9.8%) 3,9-bis (5-phenyl-2-furyl) -2,4,8,10-tetraoxaspiro / 5,5 / undecane were obtained . Melting point 182-183 ° C. Found%: C 73.1.5; H 5.4; Calculated for C ₂₇ H ₂₄ O ₆ in%: C 73.0; H 5.4.

Example Γ

0.1 mol (17.5 g) 5-phenylfurfurol and 0.03 mol (6.12 g) 1,1,3,3-tetramethylolcyclohexane were treated according to Example H 'and received 70% (11 g) 3.11-bis- (5 - Phenyl - 2 - furyl) - 2,4,10,12 - tetraoxaiiispiro / 5.1, 5.3 / hexadecane. Melting point 201 to 202 (.. Found%: C 73.2; H 6.24; calculated for C ₃₂ H ₃₂ O ,, in%: C 73.5; H 6.13.

Example J '

0.1 mol (22.2 g) of 5-naphthylfurfural and 0.03 mol (6.6 g)!,!, S ^ -Tetramelhylolcyclohexan-S-ol were treated according to Example H 'and received 64% (12 g) 3.11 bis - (5 - naphthyl - 2 - furyl) - 15 - oxy - 2.4, 10.12-tetraoxadispiro / 5.1.5.3. hexadec. Melting point 246 to 247 ° C. Found%: C 76.2; H 5.4; Calculated for C _4n H ₃₁₁ O ₇ in%: C 76.4; H 5.73.

Example K. '

0.1 mol (17.5 g) 5-phenylfurfurol and 0.03 mol (6.55 g)!,! ^, S-tetramethylolcyclohexane-S-nn were treated according to Example H 'and obtained 79% (12, 5 g) 3.11 - bis - (5 - phenyl - 2 - furyl) - 2,4,10,12 - tetraoxadispiro / 5,1,5,3 / liexadekan-l 5-one. Melting point 214 to 215 = C. Found%: C 73.0; H 5.74; Calculated for C ₃₂ H ₃₀ O ₇ in%: C 73.0; H 5.69.

Example L '

0.1 mol (10.8 g) of p-phenylenediamine base was mixed with 0.3 mol (51.6 g) of 5-phenylfurfuro! and immediately vacuumed the reaction vessel. In the course of the exothermic reaction at a temperature of 40 ^° C. (7 to 9 Torr), most of the water is distilled off. Then you turn on the heating. After 1 to 2 hours at a temperature of 40 to 60 ^° C., the reaction has ended. The product is extracted twice with boiling ether to remove the unreacted starting materials. After recrystallization from cyclohexane in an inert atmosphere, 61% (25.5 g) of N, N'-bis (5-phenylfurfurylidene) -p-phenylendiamine are obtained. Melting point 108 to 109 ^° C. Found%: C 80.6; H 4.73;

N 6.91; calculated for C ₂₈ H ₂₀ N ₂ O ₂ in%; C 80.7; H 4.81; N 6.73.

Example M '

From 0.1 mol (18.4 g) of benzidine base and 0.3 mol (56.6 g) of 5-phenylfurfural, 72 was obtained according to Example L 'after recrystallization from benzene in an argon atmosphere while filtering the solution through an aluminum oxide layer % (35.4 g) N, N'-bis (5-phenylfurfurylidene) benzidine. Melting point 146 to 149 ° C. Found%: C 83.0; H 4.74; N 5.63; Calculated for C ₃₄ H ₂₄ N ₂ O ₂ in%: C 83.0; H 4.88; N 5.7.

Example N '

From 0.05 mol (10 g) 4,4'-diaminodiphenyl oxide and 0.15 mol (25.8 g) 5-phenylfurfural, 42% (10.65 g) N, N'-bis- (5 -Phcnylfurfuryliden) -4,4'-diaminodiphenyloxid. Melting point 104-106 ° C. Found%: C 81.2; H 4.68; N 5.47; Calculated for C ₃₄ H ₂₄ N ₂ O ₃ in%: C 80.4; H 4.73; N 5.52.

Example O '

From 0.05 mol (9.8 g) 4,4'-diaminodiphenylmethiin and 0.15 mol (33.5 g) 5-naphthylfurfural obtained according to Example L '54% (15 g) N, N'-bis- (5-naphthylfurfurylidene) - 4,4'-diaminodiphenylmethane. Melting point 116 to 118 C. Found%: C 84.2; H 5.17; H 5.06; Calculated for C ₃₄ H ₂₈ N 1 O ₂ in%: C 84; H 5.03; N 5.03.

Claims (1)

Patent claims: 1. Aromatic tetracarboxylic acid dianhydrides. characterized by the general formula Means namely gaseous hydrogen chloride, hydrogen bromide, concentrated hydrochloric, hydrobromic or sulfuric acid or polyphosphoric acid ^{dehydrated for at least 30 minutes at a temperature of -30 to +110 0} C in glacial acetic acid, concentrated sulfuric acid or polyphosphoric acid as the solvent.