CA1049533A - Process for the manufacture of maleimides - Google Patents
Process for the manufacture of maleimidesInfo
- Publication number
- CA1049533A CA1049533A CA214,252A CA214252A CA1049533A CA 1049533 A CA1049533 A CA 1049533A CA 214252 A CA214252 A CA 214252A CA 1049533 A CA1049533 A CA 1049533A
- Authority
- CA
- Canada
- Prior art keywords
- acid
- employed
- process according
- polymaleamic
- alkaline earth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
- C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D207/44—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members
- C07D207/444—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members having two doubly-bound oxygen atoms directly attached in positions 2 and 5
- C07D207/448—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members having two doubly-bound oxygen atoms directly attached in positions 2 and 5 with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms, e.g. maleimide
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D207/00—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom
- C07D207/02—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D207/44—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members
- C07D207/444—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members having two doubly-bound oxygen atoms directly attached in positions 2 and 5
- C07D207/448—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members having two doubly-bound oxygen atoms directly attached in positions 2 and 5 with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms, e.g. maleimide
- C07D207/452—Heterocyclic compounds containing five-membered rings not condensed with other rings, with one nitrogen atom as the only ring hetero atom with only hydrogen or carbon atoms directly attached to the ring nitrogen atom having three double bonds between ring members or between ring members and non-ring members having two doubly-bound oxygen atoms directly attached in positions 2 and 5 with only hydrogen atoms or radicals containing only hydrogen and carbon atoms directly attached to other ring carbon atoms, e.g. maleimide with hydrocarbon radicals, substituted by hetero atoms, directly attached to the ring nitrogen atom
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Pyrrole Compounds (AREA)
- Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
Abstract of the Disclosure The invention relates to a process for the manufacture of maleimides by cyclic dehydration of corresponding maleamic acids in the presence of, preferably, acetic anhydride and an alkaline earth metal compound (catalyst). Compared to known catalysts, especially nickel salts, the alkaline earth metal compounds used as catalysts according to the invention have the advantage that the manufacturing process gives substantially greater kettle yields, and that the compounds are non-toxic. Prefer-ably, calcium oxide and calcium acetate are employed according to the invention. Corresponding barium compounds are also very suitable for use.
Description
, ~9L9533 In recent years, maleimides have acquired considera~le importance as starting materials for the manufacture of high polymers. They can be polymerised by themselves ~r in com-bina-tion with other suitable monomers, by warming or catalyti-cally. A polyaddition reaction of polymaleimides with organic polyamines is also known. Given this importance of the male- -,~,:: ... .
imides, it is necessary for the chemical raw materials indus-try -to develop advantageous processes for the manufacture of maleimides. -It is already known to manufacture bis-maleimides by reaction of the corresponding bis-maleamic acids with a lower ;
carboxylic acid anhydride (for example acetic anhydride) in the presence of an organic dlluent and of a soluble nickel deriva- ~ -tive. Such a process is described, and claimed, in DT-OS
imides, it is necessary for the chemical raw materials indus-try -to develop advantageous processes for the manufacture of maleimides. -It is already known to manufacture bis-maleimides by reaction of the corresponding bis-maleamic acids with a lower ;
carboxylic acid anhydride (for example acetic anhydride) in the presence of an organic dlluent and of a soluble nickel deriva- ~ -tive. Such a process is described, and claimed, in DT-OS
2,040,094. This Offenlegungsschrift refers to US Patent - -:. . :
Specifications 2,444,536, 3,018,290, 3,018,292 and 3,127,414 which relate to further known processes for the manufacture of maleimides. -. . . . . .
~ WhiIst the process according to DT-OS 2,040,094 repre-sents a technical advance compared to the known processes men-tioned in the same specification, it still suffers from con-siderable disadvantages. m usj for example, the kettle yield is very low (even in industrial installations). Kettles of capacity approximately 2,000 1 must be employed for the pro-duction of 70 kg of maleimide. Apart from the fact that the nickel salts used as catalysts are relatively expensive, their use is also very disadvantageous for ecological reasons. Since the effIuents contain 100 times as much nickel salts as is . .
,:.: ., - 2 - ~
: ' -.. . .
permitted at the present time and the removal of the~e salts from the efflu-ent is extremely costly, the process according to DT-OS 2,040,094 has found virtually no industrial acceptance.
British Patent No. 1,137,592 describes a multi-stage process for the manufacture of bis-maleimides in which a sodium salt of a carboxylic acid is used as the catalyst both for the manufacture of the bis-maleamic .. -~
acid and for the cyclising dehydration thereof to the imide. However, this .
process is disadvantageous inasmuch as the catalyst must be employed.lin .
high concentration (that is to say up to 3 mols per mol of the diamine ~: :
employed), which requires a costly washing operation of the end product to remove the catalyst. Furthermore, the yields obtained in carrying out this .
known process (82 to 88% of theory) are too low.
Accordingly, it is the object of the invention to discover a process which operates with a better space yield, which presents no problems with regard to the effluents (in respect of amount and toxicity) and which is thus overall substantially more economical in operation than the processes : according to the state of the art.
The subje~t of the Invention is a process for the manufacture of monomaleimides or polymaleimides by cyclising dehydration of monomaleamic '. :` .
20 : : acids or polymaleamic acids~selected from a) phenyl maleamic acid, b) a , ~.
.,.,~
polymaleamic acid of the general formula CH COOH HOOC CH `.
~! NH - R -NH !l CH CO CO CH ~ -in whlch R denotes a braliched or unbranched aliphatic radical with a total ~. .
of 10 C-atoms, a cycloaliphatic radlcal on aromatic radical or an araliphatic .~- ~
radical, c) a polymaleamic acid of the formula ` .; ;
: HO-CO-CH=CH-CO-NH NH_CO_CH=CH_CO_OH
HO-CO-CH=CH-CO-NI ~ ~I-CO-CH=CH-CO-OH
and d) a polymaleamic acid of the formula i`
~ - 3 - :
1~ - , ~
.
. ~ 5", ' ', " '", ' l~9S33 ~
HO~CO-CH=CH-CO-NH NH-CO-CH=CH-CO-OH
~ ~Vl) in the presence of lower, dehydrating, car~oxylic acid anhydrides, catalysts and tertiary amines and in the presence or absence of organic solvents, : :
:, :,- .
characterised in that the catalyst employed iS an alkaline earth metal com- :.
pound in a concentration of 0.005 to 0.2 mol per mol of the monomaleamic acid . .
or polymaleamic acid.
"'.''..-'',~
' `":'-' ' :
',':'. ' :., ':.
. ~ ..... .
. .: .
~, :, ~ ,''" '' ~: ; ~.. ~ . . ' !,., ' ', ,'; :, ,' .
~;
i~ .~,.,'' f. ' ':' .
.` ' ~:, ,~
. ~ " ' ,' ~', ' ~: ' .',"' ' ~ ,.
'`' ' ~' "'., ' - 3a - ~ . ~
,,~,~ ` '.' ,' ' ' ' r ~ ~0~S~3 The preferred range of catalyst concentration is 0.01 to 0.1 mol per mol of the maleamide!-carboxylic acid.
Particularly suitable catalysts according to the inven-, ,: . .
tlon are alkaline earth metal oxides and alkaline earth metalacetates. Calcium compounds and barium compounds are employed preferentially. The following substances should be mentioned as examples of the catalysts: calcium acetate, calcium oxide, barium acetate, barium oxide and strontium oxide. Alkaline earth metal alcoholates or corresponding complex compounds are also suitable.
- .
The dehydrating carboxylic acid anhydride used according to the invention is preferably acetic anhydride. Preferably, -2 to 3 mols of acetic anhydride should be used per mol of male- ~-amic acid.
According to the invention it is possible to employ, for ; ~ example, trialkylamines and N,N-dialkylbenzylamines with 1 to 12 C atoms as tertiary amines. Triethylamine is employed prefer-.. . .
entially. me preferred concentration of the tertiary amines is between 0.3 and 1 mol per mol of maleamic acid.
me cyclising dehydration i9 carried out at temperatures ~
between 40C and 100C, preferably at atmospheric pressure. ~ ;
Preferably, it is carried out at temperatures between 40 and , ~0C and in the presence of organic solvents.
Amongst the ~olvents ~hich can be used there may be men--tioned solvents of elevated polarity, such as, for example, dimethylformamide, dimethylacetamide, dimethylsulphoxide, N- ;-methylpyrrolidone and N-methylcaprolactam. It is also possible to use cyclic ethers, such as, for example, tetrahydrofurane _ ~j . ~ .
0~95~33 . ~ -,, :
and dioxane. The dialkyl ketone~" such as, for example, acetone and methyl ethyl ke-tone, can be used with particular advantage. Amounts by weight of solvents equivalent to between 1.5 and 2.5 times the weight of the maleamic acid : . . . .
employed are in general very suitable.
In addition to monomaleimides and polymaleimides with more than 2 imide groups (especially 3 and 4 imide groups) in the molecule, bis-maleimides can be manufactured particularly advantageously by the process according to the invention. ~-Starting products for the synthesis of these bis_maleimides are, in particular, bis-maleamic acids of the general form~la , ~ . ..... . .. . ...
CH - COOH HOOC ~ CH ;
N~ R - NH ll (I) !. ' ' CH - CO CO - CH - -, in which R denotes a branched or unbranched aliphatic radical with a total of 10 C atoms, a cycloaliphatic radical, an aro~
, B matLc radical, _ or an araliphatic radical.
Very suitable starting products are those bis-maleamic - ::
acids of the formula (I) in which R denotes a radical of the i .. . . ..
general formula : .
~ ~ _ R1 ~ (II) ~ ~
. .
CH3 ~,'. ~,, wherein Rl represents one of the radicals -CH2, -~- , -SO2-, CH~
:
-SO-, -S-, -CO- and -O-. -~ , ' ::
:, :
, ' -': '" ~' . ''" ' ' ' :'' '' '' '." ' ' ' ' `, ~ ' ,'' .' " "' ' ' ' "'' " ' '' 4~3~S~3 N,N'-4,4'-Diphenylmethane-bis-maleamlc acid and N,N'-4,4'-diphenylsulphone-bis-maleamic acid are particularly pre-ferred for use. In addition it is in principle also possible to employ all the bis-maleamic acids which are listed in DT-OS
2,04Q,094.
Furthermore, a polymaleamic acid of the formula ,`,~. ,, HO CO CH=CH CO ~l - NH.CO-CH=CH.CO OH ~
~ - - (IV) ~ ;
.. . , . .,, , ., . . ; , is also very suitable for use according to the invention. ~ ;
An example of starting products for the manufacture of tetramaleimides accord m g to the invention is the polymaleamic acid of the formula . .,, . . ..... . . . . . .. ., . . , . .. , .. . . _ . .. . . _ _ . . . . . . _ . ..
- ~
HO CO~CH=CH CO-NH NH CO CH=CH CO OH
HO CO~CH=CH CO NH ~ NH.CO CH=CH CO-OH
.. ........ _ _ . _ ., _ ,, _ __ ' .,, . . .. . .. . - - ._ .. ... . . _ . __ _ _ r , ' ~:, ;~ :
~ Phenylmaleamic acid can be used, for example~ for the ... .
manufacture of a monomaleimide. It is produced by reaction of aniline with maleic anhydride. ~
The monomaleamic acids and polymaleamic aclds used ~;
as starting materials for the process according to the invention can be manufactured according to known processes which are des-cribed in detail in the abovementioned patent specifications, -, ~ , which quote the relevant literature, Particularly suitable starting materials for the process -: :, ~ ,, ;~ .
~0~533 :: :
according to the inVention are~ however, monomaleamic acids or polymaleamic acids which have been manufactured by reaction of -maleic anhydride with primary monoamines or polyamines in the presence of organic solven~s and in the presence of 0.005 to 0.2 mol of an alkaline earth metal compound per mol of the mono-amine or polyamine.
In manufacturing these preferred starting materials, maleic anhydride is reacted with the particular monoamine or polyamine in a ratio such that 0.8 to 1.2, preferably 0.95 to -l.1, mols of maleic anhydride are present per equivalent of amlne. , ,, If the process according to the invention is carried out in 2 stages in the manner described, yet a further advantage surprisingly results. This is that~the maleamic acid produced .. .. .. .
in the 1st stage proves to be stable to heat and to polymerisa- ~ -tion. The consequence of this is that ~he organic solvent .
present from the 1st stage can be removed wholly or partially, , preferably by distillation, prior to the cyclising dehydration, ithout;producing sign1ficant amounts of by-products result1ng -~
2Q from degradation or polymerisation. This stabilising effect is particularly marked and the success of the two-stage process is opt~imal if, after carrying out the 1st stage of the process, the organic sol~ent is removed except for 50 to 75~ by weight;
in this remark, the reactants are not to be understood as solvents.
The maleimldes which can be~manufactured by the process -`according to~the inventlon are in general obtained in the form of a suspension in the particular organic solvent, and a part . -`, ' ' ~,::
', ', . :':
';'': :
-7- ~
~' .:' ` ':
~ 10~9~i33 of the particular maleimide can also be present in solution.
Complete precipitation of the desired end p~oduct is then -achieved by adding non-solvents such as, for example, water.
. . .
In most cases, -thorough washing (preferably with water) of the maleimide obtained after filtration suffices to give an ade-quately pure, industrlally usable product.
The technical advance achieved by the process according to the invention can be summarised as follows. The kettle yield is, surprisingly, substantially greater than with the pro-cess according to DT-OS 2,040,09L~, kettles of appr~ximate .
capacity 1,000 1 suffice for the production of 70 kg of male-imide. The alkaline earth metal compounds used as the catalyst a priori eliminate ~e ecological problems. As compared to the .
use of alkali metal compounds as catalysts according to known processes, the use of the alkaline earth metal compounds accord- `~
ing to the invention gives the ~ollowing advantages. Costly washing operations are not necessary since the concentration , ~ . . .
required according to the invention is much lower. It is sur-prising that higher yields (preferably 95 - 97% of theory) are achieved.
The maleimides manufactured ln accordance with the pro-cess of the invention are, surprisingly, substantially more active with regard to thermal polymerisation than the products manufactured according to known processes. This behaviourls~s~c~
WlYdesirable inasmuch as fillers and additives can be added to ~~
the reaction mixtures to be polymerised~ in order to improve the materials to be manu~actured and cheapen them, without thereby making the reactivity too low. This unexpected . , -~ . : ' ' ::' . . : ''.: ~",' ' ' : ' '' '' ~' .:
~1(~4953~3 . .
behaviour of the maleimides manufactured by the process accord~ing to the invention, though they have the same analytical data as maleimides manufactured according to known processes, particularly underlines the inventive level of the process claimed.
' ' ,',, 30.9 g of maleic anhydride (0.315 mol) and 118.0 g of acetone are initially introduced into a flask equipped with a reflux condenser and the mixture is stirred at 25C until com-plete solution is achieved.
002 g of calcium oxide (0.00356 mol) -is added to this solution and stirring is continued for 15 minutes. The mixture is warmed to 60C and a solution of 29.7 g of 4,4'-diaminodi-phenylmethane (0.149 mol) in 59.2 g of acetone is added dropwise at this temperature over the course of approx. 1 hour. -~ -87 g of acetone are distilled from the reaction mixture at a bath temperature of 60C, whilst stirring and under vacuum (approx. 40 - 100 mm Hg). A yellow crystal mass results.
2.0 g of glacial acetic acid, 48.6~ g of acetic anhydride (0.476 mol) and 5.25 g of triethylamine (0.057 mol) are added to this crystal mass. The reaction mixture is warmed to 60C and stirre~ for 2 hours at this temperature. A brown solution results. This solution is filtered warm (60C) through a fil-ter covered with silica powder and the latter is rinsed with 6.0 g of acetone. me solution is cooled to 25C. 450 ml -of water are addeu dropwise at this temperature over the course ;
! . . .
of 2 - 3 hours. A crystal suspension results. This crystal ~-suspension is cooled to 10C and stirred at this temperature ;: ~ . ' 9 ~ . -.:, . .. ~ :, .
.. ~ .
: . ' ~ ' ":' ' ., ' '-," , `:,:, ~ ' ' ' ' . ' ' ., , . ' ,.' ' . , ' , ' ' ;; , ': :~', ,""
for 1 hour. It is then filtered and the crystalline residue is rinsed with 150 ml of cold (10C) water in portions. The crystals are dried in a vacuum drying cabinet in vacuo at 80C
- Yield: 48.2 g of N,N'-4,4'-diphenylmethane-bis-male-imide, corresponding to 90.0% of theory relative to 4,4'-diamino_ -diphenylmethane (theory = 53.5 g), mel-ting point: 1~2 - 157~. -Example 2 me procedure followed is exactly as in Example 1 except that instead of 0.2 g of calcium oxide 0.3 g of calcium acetate . . .
(0.0019 mol) is employed. The result of this experiment vir-tually corresponds to the result of Example 1.
Example 3 -The procedure followed is exactly as in Example 1 except .
that instead of 0.2 g of calcium oxide 0.2 g of barium oxide (0.00118 mol) is employed. The result corresponds to that of -:
Example 1.
- Example 4 ' ,' me procedure followed is exactly as in Example 1, except - that instead of 0.2 g of calcium oxide 0.3 g of barium acetate (0.00118 mol) is employed. The result corresponds to that of Example 1.
Example 48.6 g of acetic anhydride, 5.25 g of triethylamine and 3.0 g of calcium acetate (0.019 mol) are initially intro- ;
duced into a flask equipped with a reflux condenser.
The mixture is warmed to 60C whilst stirring. A solu-tion, warmed to 60C, of 59.1 g of N,N'-4,4'-diphenylmethane-bis-maleamic acid (0.15 mol) and 144.0 g of dimethylformamide ~ . .
` ~:, . ':
-~ 109L~ii3;3~ -is added dropwise to the above mixture over the course of 1 hour at 60C. The mixture is st,rred for a fur-ther 2 hour at ~-60C. A viscous solution results.
This solution is allowed to cool to 30C and is run -, :, ~: . .
over the course of 1 hour into a mixture of 225 g of ice and 225 g of water (maximum temperature during the addition: +10C). -After completion of the addi-tion, the crystals are fil- ~
tered off and rinsed with 200 g of cold (10C) water. me -crystals are dried in vaGuo at 80C in a vacuum drying cabinet.
Yield: 51.0 g of N,N'-4,4'-diphenylmethane-bis-male-imide, corresponding to 95.4% of theory, relative to N,N'-4,4'-diphenylmethane-bis-maleamic acid. (Theory = 53.5 g).
Melting point: 156 - 159C.
Example 6 ;
28.42 g of maleic anhydride (0.29 mol) and 73 g of -:
dimethylformamide are initially introduced into a flask equipped with a reflux condenser, the mixture is warmed to 60C (~hich produces a solution) and a solution, warmed to 60C, of 29.7 g s ~
of 4,4'-diaminodiphenylmethane (0.15 mol) in 73 g of dimethyl- ;
formamide is added dropwise to the above solution over the course of 1 hour at 60C. 5.25 g of triethylamine are added to the reaction mixture. The mixture is then stirred at 60C
until a solution is produced. The latter is allowed to cool to 4bc and is added dropwise over the course of 1 hour to a mixture of 48.6 g of acetic anhydride and 3.0 g of calcium acetate (0.019 mol) at 60C.
The reaction mixture is kept for 1 hour at 50C, whilst ~;
-, stirring. A viscous solution results. This solution is , ~'' .
.
i; ~049533 allowed to cool to 30C and is added dropwise over the course of approx. 1 hour to a mixture of 225 g of ice and 225 g of water (with the temperature not exceeding 10C during the addition). :!: - :
After completion of the ad~ition, the crystals are fil~
tered off and rinsed with 200 g of water at 10C. The crystals are dried ln vacuo at 80C in a vacuum drying cabinet.
Yield: 50.6 g of N,N'-4,4'-diphenylmethane-bis-male- J
, .
imide, corresponding to 94.6% of theory, relative to 4,4'-di-aminodiphenylmethane. ( méory = 53.5 g). Melting point:
I59 - 162C. ~ '~
, Example 7 ~ , :
29.7 g of 4,4'-diaminodiphenylmethane (0.15 mol), 59.0 g of acetone and 23.7 g of benzyldimethylamine are initially introduced into a flask equipped with a reflux conden-ser. The mixture is stirred at 25C until a solution results.
, ThlS solution is cooled to 10 - 15C. A solution of 28.42 g ' of maleic anhydride (0.29 mol) in 119 g of acetone is added ~ ~' dropwise to the above~solution over the course of 1 hour at 10 - 15C.~ Thereafter, the resulting solution is added drop~
wise to a mixture of 48.6 g of acetic anhydride and 3.0 g of calcium acetate (0.019 mol)' over the course of 1 hour at 60C.
me reaction mixture is warmed to 65 - 70C. 45 g of acetone are then distilled off under normal pressure. - ;~
The viscous solution which remains is allowed to cool to , ~ , 30 - 35C and is run, over the course of 1 hour, into a mixture '~
of 225 g of ice &nd 225 g of water. After completion of the ~' addition, the crystals are filtered oPf and rinsed with 200 g `~
of water at 10 C. ' The crystals are dried in vacuo at 80C
. " ' ~, ~, '., ,',;..'. ,"' ';.' '''' '" """ '`"'"'' `' "''' "'":"' "' ' 4~S33 in a vacuum drying cabinet.
Yield: 52.0 g o~ N,N'-4,4'-diphenylmethane-bis-male-imide, corresponding to 97.2% of theory, relat~ve to 4,4'- -diaminodiphenylmethane. (Theory = 53.5 g). Melting point: !' 158 - 160C.
Example 8 ;
25.0 g of 3,3'-4,4'-biphenyltetramine (0.116 mol) and 72.0 g of dimethylformamide are initially introduced into a flask equipped with a reflux condenser. The mixture is stirred at 25C until a solution results. This solution is warmed to 60C and a solution of 48.05 g of maleic anhydride (0.49 mol) in 72.0 g of dimethylformamlde is added dropwise to the above solu~ --tion over the course of 1 hour at 60 - 65C. The reaction mix--. . .
ture is kept at 60 - 65C for 1 hour, whilst stirring. The mixture is cooled to 25C and 71.6 g of acetic anhydride ~....
(0.701 mol), 2.3 g of calcium acetate (anhydrous; 0.0145 mol) and 5.9 g of triethylamine (0.058 mol) are added in succession.
e reaction mixture is warmed to 60 - 65C and is kept at this ;
temperature for 2 hours, whilst stirring. A solution of medium viscosity results. This is allowed to cool to 30 - 35C and~9~Ogof distill~d water are run in over the course of one hour. mere-after, the resulting crystal/liquid mixture is cooled to .
0 - 5C and is kept at this temperature for one hour, whilst ~ -stirring. It is then filtered and the cryst~ls are rinsed ~-with 300 g of distilled water at 10C. The crystals are i dried in vacuo at 80C in a vacuum drying cabinet.
Yield: 48.8 g of 3,3'-4,4'-biphenyltetramaleimide, -.
corresponding to 78.2% of theory, based on 3,3'-4,4'-biphenyl-~ ~, - 13 - ;
.,~ , , . : .
: , , 11~4~9533 tetramine (theory = 62.35 g). Melting point: not character_ istic, product does not melt below 250C. N content (Kjehldal method): 88.95% of the theoretical content free amine (by ti-.
tration with sodium nitrite):~ 0 3%.
- Example 9 45.0 g of aniline (0.483 mol) and 100.0 g of dimethyl-,: , formamide are introduced into a flask equipped with a reflux condenser. The mixture is stirred at 25C until a solution results. This solution is warmed to 60C. A solution of 49.7 g of maleic anhydride (0.506 mol) in 74.0 g of dimethyl-formamide is added dropwise to the above solution over the course of 1 hour at 60 - 65C. me reaction mixture is kept ~t 60 - 65C for 1 hour, whilst stirring. It is then cooled to 25C and 7~.9 g of acetic anhydride (0.723 mol), 9.5 g of calcium acetate (anhydrous; o.o60 mol) and 14. 6 g of triethyl-amine (0.144 mol) are added in succession. me reaction mix- --ture is warmed to 60 - 65C and kept at this temperature for ~ -2 hours, whllst stirring. A solution of medium viscosity results, which is cooled to 30 - 35C. 1,000.0 g of distilled water are allowed to run in over the course of 1 hour. The ~ -mixture containing the crystals is then cooled to 0 - 5C and stirred at this temperature for 1 hour. It is then filtered and the crystals are rinsed with 400 g of distilled water at 10C. The crystals are dried in vacuo at 50C in a vacuum drying cabinet.
Yield: 73.0 g of phenylmaleimide, corresponding to 88.2% of theory, relative to aniline (theory = 83.67 g). Melt- ;
ing point: 76 - 78C. N content (Kjehldal method): 94.1~%.
: , .'.. ' '' . ~
~4953~
Free amine: ~ 0.2%.
Example 10 - -45.0 g of 4,4'-dia~inodiphenylsulphone (0.1812 mol) and 100.0 g of dimethylformamide are introduced into a flask eq~ipped -with a reflux condenser. The mixture is stirred at Z5C until a solution results. This solution is warmed to 60C. A
solution of 37.1 g of maleic anhydride (0.378 mol) in 68.0 g of dimethylformamide is added dropwise to the above solution over the course of 1 hour at 60 - 65C. The reaction mixture is -stirred for 1 hour~ at 60 - 65C. It is then cooled to 25C
and 55.8 g of acetic anhydride (0.5465 mol), 3.57 g of calcium acetate (anhydrcus; 0.0225 mol) and 5.49 g of triethylamine (0.0543 mol) are added in succession. The reaction mixture is warmed to 60 - 65C and kept at this temperature for 2 hours, ;
whilst stirring. A solution of medium viscosity results, which is allowed to cool to 30 - 35C. 1,000 g of distilled water ;
are run in over the course of one hour. The mixture is then cooled to 0 - 5C and stirred at this temperature for 1 hour.
It is then filtered~and the crystals are rinsed with 300 g of ;
distilled water at 10C. The crystals are dried in vacuo at 100C in a vacuum drying cabinet.
Yield: 71.6 g of N,N'-4,4'-diphenylsulphone-bis-maleimide,corresponding to 96,7% of theory, relative to 4,4'-- , .
diaminodiphenylsulphone (theory = 74.01 g). Melting poin-c: `
154 - 148C. N content (Kjehldahl method): 84.25%. Free amine (by titration with sodium nltrite) ~ 0.3%. S content ~determined gravimetrically via Ba504): 92.0% of the theoretL- `
cal content.
-~' ::
.,,-.
, . ' ' ' ', . . ' Example 11 35.0 g of 3,6-diaminodiphenylene oxide (0.1765 mol) and 200.0 g of dimethylformamide are initially introduced into a flask equipped with a reflux condenser. me mix-ture is warmed to 60C and the product is dissolved at this temperature.
Thereafter a solution of 36.3 g of maleic anhydride (0.370 mol) in 70.0 g of dimethyl~ormamide is added dropwise to this solu- ;
tion over the course of 1 hour at 60 - 65C. The reaction mixture is stirred for 1 hour at 60 - 65C and then cooled to -25C. 54.1 g of acetic anhydride (0.5299 mol), 3.62 g of calcium acetate (anhydrous; 0.0228 mol) and 5.35 g of triethyl-amlne (0.0529 mol) are introduced in succession. The reaction ; ;
mixture is warmed to 60 - 65C and kept at this temperature for 2 hours, whilst stirring. A solution of medium viscosity `
results, which is allowed to cool to 30 - 35C. 1,300 g of distilled water are run in over the course of one hour. The mixture is then cooled to 0 - 5C and kept at this tempera-ture for 1 hour whilst stirring. The resulting crystals are `
then filtered off and rinsed with 300 g of distilled water at 10C. The crystals are dried in vacuo at 100C in a vacuum drying cabinet.
Yield: 59.53 g o~ N,N-3,6-dimaleimide-diphenylene oxide, corresponding to 93.60/o of theory, relative to 3,6-diaminodi-phenylene oxide (theory = 63.61 g). Melting point: 179 -181C. N content (Kjehldal method): 92.76%. Free amine . .
(by tLtration with sodium nitrite): < 0.3%.
. ;. :
:` . '~'.', : ,: .
Specifications 2,444,536, 3,018,290, 3,018,292 and 3,127,414 which relate to further known processes for the manufacture of maleimides. -. . . . . .
~ WhiIst the process according to DT-OS 2,040,094 repre-sents a technical advance compared to the known processes men-tioned in the same specification, it still suffers from con-siderable disadvantages. m usj for example, the kettle yield is very low (even in industrial installations). Kettles of capacity approximately 2,000 1 must be employed for the pro-duction of 70 kg of maleimide. Apart from the fact that the nickel salts used as catalysts are relatively expensive, their use is also very disadvantageous for ecological reasons. Since the effIuents contain 100 times as much nickel salts as is . .
,:.: ., - 2 - ~
: ' -.. . .
permitted at the present time and the removal of the~e salts from the efflu-ent is extremely costly, the process according to DT-OS 2,040,094 has found virtually no industrial acceptance.
British Patent No. 1,137,592 describes a multi-stage process for the manufacture of bis-maleimides in which a sodium salt of a carboxylic acid is used as the catalyst both for the manufacture of the bis-maleamic .. -~
acid and for the cyclising dehydration thereof to the imide. However, this .
process is disadvantageous inasmuch as the catalyst must be employed.lin .
high concentration (that is to say up to 3 mols per mol of the diamine ~: :
employed), which requires a costly washing operation of the end product to remove the catalyst. Furthermore, the yields obtained in carrying out this .
known process (82 to 88% of theory) are too low.
Accordingly, it is the object of the invention to discover a process which operates with a better space yield, which presents no problems with regard to the effluents (in respect of amount and toxicity) and which is thus overall substantially more economical in operation than the processes : according to the state of the art.
The subje~t of the Invention is a process for the manufacture of monomaleimides or polymaleimides by cyclising dehydration of monomaleamic '. :` .
20 : : acids or polymaleamic acids~selected from a) phenyl maleamic acid, b) a , ~.
.,.,~
polymaleamic acid of the general formula CH COOH HOOC CH `.
~! NH - R -NH !l CH CO CO CH ~ -in whlch R denotes a braliched or unbranched aliphatic radical with a total ~. .
of 10 C-atoms, a cycloaliphatic radlcal on aromatic radical or an araliphatic .~- ~
radical, c) a polymaleamic acid of the formula ` .; ;
: HO-CO-CH=CH-CO-NH NH_CO_CH=CH_CO_OH
HO-CO-CH=CH-CO-NI ~ ~I-CO-CH=CH-CO-OH
and d) a polymaleamic acid of the formula i`
~ - 3 - :
1~ - , ~
.
. ~ 5", ' ', " '", ' l~9S33 ~
HO~CO-CH=CH-CO-NH NH-CO-CH=CH-CO-OH
~ ~Vl) in the presence of lower, dehydrating, car~oxylic acid anhydrides, catalysts and tertiary amines and in the presence or absence of organic solvents, : :
:, :,- .
characterised in that the catalyst employed iS an alkaline earth metal com- :.
pound in a concentration of 0.005 to 0.2 mol per mol of the monomaleamic acid . .
or polymaleamic acid.
"'.''..-'',~
' `":'-' ' :
',':'. ' :., ':.
. ~ ..... .
. .: .
~, :, ~ ,''" '' ~: ; ~.. ~ . . ' !,., ' ', ,'; :, ,' .
~;
i~ .~,.,'' f. ' ':' .
.` ' ~:, ,~
. ~ " ' ,' ~', ' ~: ' .',"' ' ~ ,.
'`' ' ~' "'., ' - 3a - ~ . ~
,,~,~ ` '.' ,' ' ' ' r ~ ~0~S~3 The preferred range of catalyst concentration is 0.01 to 0.1 mol per mol of the maleamide!-carboxylic acid.
Particularly suitable catalysts according to the inven-, ,: . .
tlon are alkaline earth metal oxides and alkaline earth metalacetates. Calcium compounds and barium compounds are employed preferentially. The following substances should be mentioned as examples of the catalysts: calcium acetate, calcium oxide, barium acetate, barium oxide and strontium oxide. Alkaline earth metal alcoholates or corresponding complex compounds are also suitable.
- .
The dehydrating carboxylic acid anhydride used according to the invention is preferably acetic anhydride. Preferably, -2 to 3 mols of acetic anhydride should be used per mol of male- ~-amic acid.
According to the invention it is possible to employ, for ; ~ example, trialkylamines and N,N-dialkylbenzylamines with 1 to 12 C atoms as tertiary amines. Triethylamine is employed prefer-.. . .
entially. me preferred concentration of the tertiary amines is between 0.3 and 1 mol per mol of maleamic acid.
me cyclising dehydration i9 carried out at temperatures ~
between 40C and 100C, preferably at atmospheric pressure. ~ ;
Preferably, it is carried out at temperatures between 40 and , ~0C and in the presence of organic solvents.
Amongst the ~olvents ~hich can be used there may be men--tioned solvents of elevated polarity, such as, for example, dimethylformamide, dimethylacetamide, dimethylsulphoxide, N- ;-methylpyrrolidone and N-methylcaprolactam. It is also possible to use cyclic ethers, such as, for example, tetrahydrofurane _ ~j . ~ .
0~95~33 . ~ -,, :
and dioxane. The dialkyl ketone~" such as, for example, acetone and methyl ethyl ke-tone, can be used with particular advantage. Amounts by weight of solvents equivalent to between 1.5 and 2.5 times the weight of the maleamic acid : . . . .
employed are in general very suitable.
In addition to monomaleimides and polymaleimides with more than 2 imide groups (especially 3 and 4 imide groups) in the molecule, bis-maleimides can be manufactured particularly advantageously by the process according to the invention. ~-Starting products for the synthesis of these bis_maleimides are, in particular, bis-maleamic acids of the general form~la , ~ . ..... . .. . ...
CH - COOH HOOC ~ CH ;
N~ R - NH ll (I) !. ' ' CH - CO CO - CH - -, in which R denotes a branched or unbranched aliphatic radical with a total of 10 C atoms, a cycloaliphatic radical, an aro~
, B matLc radical, _ or an araliphatic radical.
Very suitable starting products are those bis-maleamic - ::
acids of the formula (I) in which R denotes a radical of the i .. . . ..
general formula : .
~ ~ _ R1 ~ (II) ~ ~
. .
CH3 ~,'. ~,, wherein Rl represents one of the radicals -CH2, -~- , -SO2-, CH~
:
-SO-, -S-, -CO- and -O-. -~ , ' ::
:, :
, ' -': '" ~' . ''" ' ' ' :'' '' '' '." ' ' ' ' `, ~ ' ,'' .' " "' ' ' ' "'' " ' '' 4~3~S~3 N,N'-4,4'-Diphenylmethane-bis-maleamlc acid and N,N'-4,4'-diphenylsulphone-bis-maleamic acid are particularly pre-ferred for use. In addition it is in principle also possible to employ all the bis-maleamic acids which are listed in DT-OS
2,04Q,094.
Furthermore, a polymaleamic acid of the formula ,`,~. ,, HO CO CH=CH CO ~l - NH.CO-CH=CH.CO OH ~
~ - - (IV) ~ ;
.. . , . .,, , ., . . ; , is also very suitable for use according to the invention. ~ ;
An example of starting products for the manufacture of tetramaleimides accord m g to the invention is the polymaleamic acid of the formula . .,, . . ..... . . . . . .. ., . . , . .. , .. . . _ . .. . . _ _ . . . . . . _ . ..
- ~
HO CO~CH=CH CO-NH NH CO CH=CH CO OH
HO CO~CH=CH CO NH ~ NH.CO CH=CH CO-OH
.. ........ _ _ . _ ., _ ,, _ __ ' .,, . . .. . .. . - - ._ .. ... . . _ . __ _ _ r , ' ~:, ;~ :
~ Phenylmaleamic acid can be used, for example~ for the ... .
manufacture of a monomaleimide. It is produced by reaction of aniline with maleic anhydride. ~
The monomaleamic acids and polymaleamic aclds used ~;
as starting materials for the process according to the invention can be manufactured according to known processes which are des-cribed in detail in the abovementioned patent specifications, -, ~ , which quote the relevant literature, Particularly suitable starting materials for the process -: :, ~ ,, ;~ .
~0~533 :: :
according to the inVention are~ however, monomaleamic acids or polymaleamic acids which have been manufactured by reaction of -maleic anhydride with primary monoamines or polyamines in the presence of organic solven~s and in the presence of 0.005 to 0.2 mol of an alkaline earth metal compound per mol of the mono-amine or polyamine.
In manufacturing these preferred starting materials, maleic anhydride is reacted with the particular monoamine or polyamine in a ratio such that 0.8 to 1.2, preferably 0.95 to -l.1, mols of maleic anhydride are present per equivalent of amlne. , ,, If the process according to the invention is carried out in 2 stages in the manner described, yet a further advantage surprisingly results. This is that~the maleamic acid produced .. .. .. .
in the 1st stage proves to be stable to heat and to polymerisa- ~ -tion. The consequence of this is that ~he organic solvent .
present from the 1st stage can be removed wholly or partially, , preferably by distillation, prior to the cyclising dehydration, ithout;producing sign1ficant amounts of by-products result1ng -~
2Q from degradation or polymerisation. This stabilising effect is particularly marked and the success of the two-stage process is opt~imal if, after carrying out the 1st stage of the process, the organic sol~ent is removed except for 50 to 75~ by weight;
in this remark, the reactants are not to be understood as solvents.
The maleimldes which can be~manufactured by the process -`according to~the inventlon are in general obtained in the form of a suspension in the particular organic solvent, and a part . -`, ' ' ~,::
', ', . :':
';'': :
-7- ~
~' .:' ` ':
~ 10~9~i33 of the particular maleimide can also be present in solution.
Complete precipitation of the desired end p~oduct is then -achieved by adding non-solvents such as, for example, water.
. . .
In most cases, -thorough washing (preferably with water) of the maleimide obtained after filtration suffices to give an ade-quately pure, industrlally usable product.
The technical advance achieved by the process according to the invention can be summarised as follows. The kettle yield is, surprisingly, substantially greater than with the pro-cess according to DT-OS 2,040,09L~, kettles of appr~ximate .
capacity 1,000 1 suffice for the production of 70 kg of male-imide. The alkaline earth metal compounds used as the catalyst a priori eliminate ~e ecological problems. As compared to the .
use of alkali metal compounds as catalysts according to known processes, the use of the alkaline earth metal compounds accord- `~
ing to the invention gives the ~ollowing advantages. Costly washing operations are not necessary since the concentration , ~ . . .
required according to the invention is much lower. It is sur-prising that higher yields (preferably 95 - 97% of theory) are achieved.
The maleimides manufactured ln accordance with the pro-cess of the invention are, surprisingly, substantially more active with regard to thermal polymerisation than the products manufactured according to known processes. This behaviourls~s~c~
WlYdesirable inasmuch as fillers and additives can be added to ~~
the reaction mixtures to be polymerised~ in order to improve the materials to be manu~actured and cheapen them, without thereby making the reactivity too low. This unexpected . , -~ . : ' ' ::' . . : ''.: ~",' ' ' : ' '' '' ~' .:
~1(~4953~3 . .
behaviour of the maleimides manufactured by the process accord~ing to the invention, though they have the same analytical data as maleimides manufactured according to known processes, particularly underlines the inventive level of the process claimed.
' ' ,',, 30.9 g of maleic anhydride (0.315 mol) and 118.0 g of acetone are initially introduced into a flask equipped with a reflux condenser and the mixture is stirred at 25C until com-plete solution is achieved.
002 g of calcium oxide (0.00356 mol) -is added to this solution and stirring is continued for 15 minutes. The mixture is warmed to 60C and a solution of 29.7 g of 4,4'-diaminodi-phenylmethane (0.149 mol) in 59.2 g of acetone is added dropwise at this temperature over the course of approx. 1 hour. -~ -87 g of acetone are distilled from the reaction mixture at a bath temperature of 60C, whilst stirring and under vacuum (approx. 40 - 100 mm Hg). A yellow crystal mass results.
2.0 g of glacial acetic acid, 48.6~ g of acetic anhydride (0.476 mol) and 5.25 g of triethylamine (0.057 mol) are added to this crystal mass. The reaction mixture is warmed to 60C and stirre~ for 2 hours at this temperature. A brown solution results. This solution is filtered warm (60C) through a fil-ter covered with silica powder and the latter is rinsed with 6.0 g of acetone. me solution is cooled to 25C. 450 ml -of water are addeu dropwise at this temperature over the course ;
! . . .
of 2 - 3 hours. A crystal suspension results. This crystal ~-suspension is cooled to 10C and stirred at this temperature ;: ~ . ' 9 ~ . -.:, . .. ~ :, .
.. ~ .
: . ' ~ ' ":' ' ., ' '-," , `:,:, ~ ' ' ' ' . ' ' ., , . ' ,.' ' . , ' , ' ' ;; , ': :~', ,""
for 1 hour. It is then filtered and the crystalline residue is rinsed with 150 ml of cold (10C) water in portions. The crystals are dried in a vacuum drying cabinet in vacuo at 80C
- Yield: 48.2 g of N,N'-4,4'-diphenylmethane-bis-male-imide, corresponding to 90.0% of theory relative to 4,4'-diamino_ -diphenylmethane (theory = 53.5 g), mel-ting point: 1~2 - 157~. -Example 2 me procedure followed is exactly as in Example 1 except that instead of 0.2 g of calcium oxide 0.3 g of calcium acetate . . .
(0.0019 mol) is employed. The result of this experiment vir-tually corresponds to the result of Example 1.
Example 3 -The procedure followed is exactly as in Example 1 except .
that instead of 0.2 g of calcium oxide 0.2 g of barium oxide (0.00118 mol) is employed. The result corresponds to that of -:
Example 1.
- Example 4 ' ,' me procedure followed is exactly as in Example 1, except - that instead of 0.2 g of calcium oxide 0.3 g of barium acetate (0.00118 mol) is employed. The result corresponds to that of Example 1.
Example 48.6 g of acetic anhydride, 5.25 g of triethylamine and 3.0 g of calcium acetate (0.019 mol) are initially intro- ;
duced into a flask equipped with a reflux condenser.
The mixture is warmed to 60C whilst stirring. A solu-tion, warmed to 60C, of 59.1 g of N,N'-4,4'-diphenylmethane-bis-maleamic acid (0.15 mol) and 144.0 g of dimethylformamide ~ . .
` ~:, . ':
-~ 109L~ii3;3~ -is added dropwise to the above mixture over the course of 1 hour at 60C. The mixture is st,rred for a fur-ther 2 hour at ~-60C. A viscous solution results.
This solution is allowed to cool to 30C and is run -, :, ~: . .
over the course of 1 hour into a mixture of 225 g of ice and 225 g of water (maximum temperature during the addition: +10C). -After completion of the addi-tion, the crystals are fil- ~
tered off and rinsed with 200 g of cold (10C) water. me -crystals are dried in vaGuo at 80C in a vacuum drying cabinet.
Yield: 51.0 g of N,N'-4,4'-diphenylmethane-bis-male-imide, corresponding to 95.4% of theory, relative to N,N'-4,4'-diphenylmethane-bis-maleamic acid. (Theory = 53.5 g).
Melting point: 156 - 159C.
Example 6 ;
28.42 g of maleic anhydride (0.29 mol) and 73 g of -:
dimethylformamide are initially introduced into a flask equipped with a reflux condenser, the mixture is warmed to 60C (~hich produces a solution) and a solution, warmed to 60C, of 29.7 g s ~
of 4,4'-diaminodiphenylmethane (0.15 mol) in 73 g of dimethyl- ;
formamide is added dropwise to the above solution over the course of 1 hour at 60C. 5.25 g of triethylamine are added to the reaction mixture. The mixture is then stirred at 60C
until a solution is produced. The latter is allowed to cool to 4bc and is added dropwise over the course of 1 hour to a mixture of 48.6 g of acetic anhydride and 3.0 g of calcium acetate (0.019 mol) at 60C.
The reaction mixture is kept for 1 hour at 50C, whilst ~;
-, stirring. A viscous solution results. This solution is , ~'' .
.
i; ~049533 allowed to cool to 30C and is added dropwise over the course of approx. 1 hour to a mixture of 225 g of ice and 225 g of water (with the temperature not exceeding 10C during the addition). :!: - :
After completion of the ad~ition, the crystals are fil~
tered off and rinsed with 200 g of water at 10C. The crystals are dried ln vacuo at 80C in a vacuum drying cabinet.
Yield: 50.6 g of N,N'-4,4'-diphenylmethane-bis-male- J
, .
imide, corresponding to 94.6% of theory, relative to 4,4'-di-aminodiphenylmethane. ( méory = 53.5 g). Melting point:
I59 - 162C. ~ '~
, Example 7 ~ , :
29.7 g of 4,4'-diaminodiphenylmethane (0.15 mol), 59.0 g of acetone and 23.7 g of benzyldimethylamine are initially introduced into a flask equipped with a reflux conden-ser. The mixture is stirred at 25C until a solution results.
, ThlS solution is cooled to 10 - 15C. A solution of 28.42 g ' of maleic anhydride (0.29 mol) in 119 g of acetone is added ~ ~' dropwise to the above~solution over the course of 1 hour at 10 - 15C.~ Thereafter, the resulting solution is added drop~
wise to a mixture of 48.6 g of acetic anhydride and 3.0 g of calcium acetate (0.019 mol)' over the course of 1 hour at 60C.
me reaction mixture is warmed to 65 - 70C. 45 g of acetone are then distilled off under normal pressure. - ;~
The viscous solution which remains is allowed to cool to , ~ , 30 - 35C and is run, over the course of 1 hour, into a mixture '~
of 225 g of ice &nd 225 g of water. After completion of the ~' addition, the crystals are filtered oPf and rinsed with 200 g `~
of water at 10 C. ' The crystals are dried in vacuo at 80C
. " ' ~, ~, '., ,',;..'. ,"' ';.' '''' '" """ '`"'"'' `' "''' "'":"' "' ' 4~S33 in a vacuum drying cabinet.
Yield: 52.0 g o~ N,N'-4,4'-diphenylmethane-bis-male-imide, corresponding to 97.2% of theory, relat~ve to 4,4'- -diaminodiphenylmethane. (Theory = 53.5 g). Melting point: !' 158 - 160C.
Example 8 ;
25.0 g of 3,3'-4,4'-biphenyltetramine (0.116 mol) and 72.0 g of dimethylformamide are initially introduced into a flask equipped with a reflux condenser. The mixture is stirred at 25C until a solution results. This solution is warmed to 60C and a solution of 48.05 g of maleic anhydride (0.49 mol) in 72.0 g of dimethylformamlde is added dropwise to the above solu~ --tion over the course of 1 hour at 60 - 65C. The reaction mix--. . .
ture is kept at 60 - 65C for 1 hour, whilst stirring. The mixture is cooled to 25C and 71.6 g of acetic anhydride ~....
(0.701 mol), 2.3 g of calcium acetate (anhydrous; 0.0145 mol) and 5.9 g of triethylamine (0.058 mol) are added in succession.
e reaction mixture is warmed to 60 - 65C and is kept at this ;
temperature for 2 hours, whilst stirring. A solution of medium viscosity results. This is allowed to cool to 30 - 35C and~9~Ogof distill~d water are run in over the course of one hour. mere-after, the resulting crystal/liquid mixture is cooled to .
0 - 5C and is kept at this temperature for one hour, whilst ~ -stirring. It is then filtered and the cryst~ls are rinsed ~-with 300 g of distilled water at 10C. The crystals are i dried in vacuo at 80C in a vacuum drying cabinet.
Yield: 48.8 g of 3,3'-4,4'-biphenyltetramaleimide, -.
corresponding to 78.2% of theory, based on 3,3'-4,4'-biphenyl-~ ~, - 13 - ;
.,~ , , . : .
: , , 11~4~9533 tetramine (theory = 62.35 g). Melting point: not character_ istic, product does not melt below 250C. N content (Kjehldal method): 88.95% of the theoretical content free amine (by ti-.
tration with sodium nitrite):~ 0 3%.
- Example 9 45.0 g of aniline (0.483 mol) and 100.0 g of dimethyl-,: , formamide are introduced into a flask equipped with a reflux condenser. The mixture is stirred at 25C until a solution results. This solution is warmed to 60C. A solution of 49.7 g of maleic anhydride (0.506 mol) in 74.0 g of dimethyl-formamide is added dropwise to the above solution over the course of 1 hour at 60 - 65C. me reaction mixture is kept ~t 60 - 65C for 1 hour, whilst stirring. It is then cooled to 25C and 7~.9 g of acetic anhydride (0.723 mol), 9.5 g of calcium acetate (anhydrous; o.o60 mol) and 14. 6 g of triethyl-amine (0.144 mol) are added in succession. me reaction mix- --ture is warmed to 60 - 65C and kept at this temperature for ~ -2 hours, whllst stirring. A solution of medium viscosity results, which is cooled to 30 - 35C. 1,000.0 g of distilled water are allowed to run in over the course of 1 hour. The ~ -mixture containing the crystals is then cooled to 0 - 5C and stirred at this temperature for 1 hour. It is then filtered and the crystals are rinsed with 400 g of distilled water at 10C. The crystals are dried in vacuo at 50C in a vacuum drying cabinet.
Yield: 73.0 g of phenylmaleimide, corresponding to 88.2% of theory, relative to aniline (theory = 83.67 g). Melt- ;
ing point: 76 - 78C. N content (Kjehldal method): 94.1~%.
: , .'.. ' '' . ~
~4953~
Free amine: ~ 0.2%.
Example 10 - -45.0 g of 4,4'-dia~inodiphenylsulphone (0.1812 mol) and 100.0 g of dimethylformamide are introduced into a flask eq~ipped -with a reflux condenser. The mixture is stirred at Z5C until a solution results. This solution is warmed to 60C. A
solution of 37.1 g of maleic anhydride (0.378 mol) in 68.0 g of dimethylformamide is added dropwise to the above solution over the course of 1 hour at 60 - 65C. The reaction mixture is -stirred for 1 hour~ at 60 - 65C. It is then cooled to 25C
and 55.8 g of acetic anhydride (0.5465 mol), 3.57 g of calcium acetate (anhydrcus; 0.0225 mol) and 5.49 g of triethylamine (0.0543 mol) are added in succession. The reaction mixture is warmed to 60 - 65C and kept at this temperature for 2 hours, ;
whilst stirring. A solution of medium viscosity results, which is allowed to cool to 30 - 35C. 1,000 g of distilled water ;
are run in over the course of one hour. The mixture is then cooled to 0 - 5C and stirred at this temperature for 1 hour.
It is then filtered~and the crystals are rinsed with 300 g of ;
distilled water at 10C. The crystals are dried in vacuo at 100C in a vacuum drying cabinet.
Yield: 71.6 g of N,N'-4,4'-diphenylsulphone-bis-maleimide,corresponding to 96,7% of theory, relative to 4,4'-- , .
diaminodiphenylsulphone (theory = 74.01 g). Melting poin-c: `
154 - 148C. N content (Kjehldahl method): 84.25%. Free amine (by titration with sodium nltrite) ~ 0.3%. S content ~determined gravimetrically via Ba504): 92.0% of the theoretL- `
cal content.
-~' ::
.,,-.
, . ' ' ' ', . . ' Example 11 35.0 g of 3,6-diaminodiphenylene oxide (0.1765 mol) and 200.0 g of dimethylformamide are initially introduced into a flask equipped with a reflux condenser. me mix-ture is warmed to 60C and the product is dissolved at this temperature.
Thereafter a solution of 36.3 g of maleic anhydride (0.370 mol) in 70.0 g of dimethyl~ormamide is added dropwise to this solu- ;
tion over the course of 1 hour at 60 - 65C. The reaction mixture is stirred for 1 hour at 60 - 65C and then cooled to -25C. 54.1 g of acetic anhydride (0.5299 mol), 3.62 g of calcium acetate (anhydrous; 0.0228 mol) and 5.35 g of triethyl-amlne (0.0529 mol) are introduced in succession. The reaction ; ;
mixture is warmed to 60 - 65C and kept at this temperature for 2 hours, whilst stirring. A solution of medium viscosity `
results, which is allowed to cool to 30 - 35C. 1,300 g of distilled water are run in over the course of one hour. The mixture is then cooled to 0 - 5C and kept at this tempera-ture for 1 hour whilst stirring. The resulting crystals are `
then filtered off and rinsed with 300 g of distilled water at 10C. The crystals are dried in vacuo at 100C in a vacuum drying cabinet.
Yield: 59.53 g o~ N,N-3,6-dimaleimide-diphenylene oxide, corresponding to 93.60/o of theory, relative to 3,6-diaminodi-phenylene oxide (theory = 63.61 g). Melting point: 179 -181C. N content (Kjehldal method): 92.76%. Free amine . .
(by tLtration with sodium nitrite): < 0.3%.
. ;. :
:` . '~'.', : ,: .
Claims (14)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for the manufacture of monomaleimides or polymaleimides by cyclising dehydration of monomaleamic acids or polymaleamic acids selected from a) phenyl maleamic acid, b) a polymaleamic acid of the general formula (I) in which R denotes a branched or unbranched aliphatic radical with a total of 10 C-atoms, a cycloaliphatic radical on aromatic radical or an araliphatic radical, c) a polymaleamic acid of the formula (II) I I ) and d) a polymaleamic acid of the formula (VI) (VI) in the presence of lower, dehydrating, carboxylic acid anhydrides, catalysts and tertiary amines and in the presence or absence of organic solvents, characterised in that the catalyst employed is an alkaline earth metal com-pound in a concentration of 0.005 to 0.2 mol per mol of the monomaleamic or polymaleamic acid.
2. Process according to claim 1, characterised in that the alkaline earth metal compound is employed in a concentration of 0.01 to 0.1 mol per mol of the monomaleamic acid or polymaleamic acid.
3. Process according to claim 1, characterised in that an alkaline earth metal oxide is employed as the alkaline earth metal compound.
4. Process according to claim 1, characterised in that an alkaline earth metal acetate is employed as the alkaline earth metal compound.
5. Process according to claim 1, characterised in that a calcium compound or barium compound is employed as the alkaline earth metal compound.
6. Process according to claim 1, characterised in that a polymaleamic acid of the formula (I) in which R denotes a radical of the formula (II) wherein R1 represents one of the radicals -CH2-, , -SO2-, -SO-, -S-, -CO-and -O-, is employed.
7. Process according to claim 6, characterised in that N,N'-4,4'-diphenylmethane-bis-maleamic acid or N,N'-4,4'-diphenylsulphone-bis-maleamic acid is employed as the polymaleamic acid of the formula (I).
8. Process according to claim l, characterised in that the cyclising dehydration is carried out at temperatures between 40 and 60°C.
9. Process according to claim 1, characterised in that monomaleamic or polymaleamic acids are employed which have been manufactured by reaction of maleic anhydride with primary monoamines or polyamines in the presence of organic solvents and in the presence of 0.005 to 0.2 mol of an alkaline earth compound per mol of the monoamine or polyamine.
10. Process according to claim 9, characterised in that monomaleamic acids or polymaleamic acids are employed which have been manufactured by reaction of maleic anhydride and the particular monoamine or polyamine in a ratio such that there are 0.8 to 1.2 mols of maleic anhydride per equivalent of amine.
11. Process according to claim 10, characterised in that monomale-amic acids or polymaleamic acids are employed which have been manufactured by reaction of maleic anhydride and the particular monoamine or polyamine in a ratio such that there are 0.95 to 1.1 mols of maleic anhydride per equivalent of amine.
12. Process according to claim 1, characterised in that a polymale-amic acid of the formula (III) is employed.
13. Process according to claim 1, characterised in that phenyl-maleamic acid is employed as the monomaleamic acid.
14. Process according to claim 1, characterised in that a poly-maleamic acid of the formula (IV) is employed.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH1647173A CH581105A5 (en) | 1973-11-22 | 1973-11-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1049533A true CA1049533A (en) | 1979-02-27 |
Family
ID=4417672
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA214,252A Expired CA1049533A (en) | 1973-11-22 | 1974-11-20 | Process for the manufacture of maleimides |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS587620B2 (en) |
| CA (1) | CA1049533A (en) |
| CH (1) | CH581105A5 (en) |
| DD (1) | DD114073A5 (en) |
| DE (1) | DE2454856C2 (en) |
| FR (1) | FR2252338B1 (en) |
| GB (1) | GB1473379A (en) |
| SU (1) | SU546278A3 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH597184A5 (en) * | 1976-04-09 | 1978-03-31 | Ciba Geigy Ag | |
| US4154737A (en) | 1976-05-05 | 1979-05-15 | E. I. Du Pont De Nemours And Company | Preparation of maleimides and dimaleimides |
| CA1111997A (en) * | 1977-10-17 | 1981-11-03 | John M. Corbett | Imide-crosslinked ethylenic polymer resin foams |
| CH634558A5 (en) * | 1978-04-06 | 1983-02-15 | Ciba Geigy Ag | METHOD FOR PRODUCING ALIPHATIC N-SUBSTITUTED MALEINIMIDES. |
| JPS6019746B2 (en) * | 1978-07-17 | 1985-05-17 | 三井東圧化学株式会社 | Polyimide manufacturing method |
| JPS6019902B2 (en) * | 1979-03-28 | 1985-05-18 | 三井東圧化学株式会社 | Dimer of isopropenylphenylmaleimide derivative |
| JPS59204171A (en) * | 1983-04-28 | 1984-11-19 | Dainippon Pharmaceut Co Ltd | Maleimide derivative |
| JPH0695036B2 (en) * | 1985-04-09 | 1994-11-24 | 株式会社ブリヂストン | Weight measuring device |
-
1973
- 1973-11-22 CH CH1647173A patent/CH581105A5/xx not_active IP Right Cessation
-
1974
- 1974-10-30 SU SU2073417A patent/SU546278A3/en active
- 1974-11-19 DE DE19742454856 patent/DE2454856C2/en not_active Expired
- 1974-11-20 DD DD18247474A patent/DD114073A5/xx unknown
- 1974-11-20 CA CA214,252A patent/CA1049533A/en not_active Expired
- 1974-11-21 FR FR7438265A patent/FR2252338B1/fr not_active Expired
- 1974-11-22 GB GB5076174A patent/GB1473379A/en not_active Expired
- 1974-11-22 JP JP13504374A patent/JPS587620B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5083368A (en) | 1975-07-05 |
| GB1473379A (en) | 1977-05-11 |
| CH581105A5 (en) | 1976-10-29 |
| JPS587620B2 (en) | 1983-02-10 |
| DE2454856C2 (en) | 1982-12-23 |
| SU546278A3 (en) | 1977-02-05 |
| FR2252338A1 (en) | 1975-06-20 |
| DE2454856A1 (en) | 1975-05-28 |
| DD114073A5 (en) | 1975-07-12 |
| FR2252338B1 (en) | 1976-10-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3018290A (en) | Preparation of maleimides | |
| US4667012A (en) | Imidazolinone-containing polymer and copolymer | |
| CA1049533A (en) | Process for the manufacture of maleimides | |
| US4777237A (en) | Polymer from (1) bis-imide, (2) allyloxy-phenyl maleimide and (3) diamine | |
| US3763211A (en) | Aminophenoxy benzonitriles | |
| US6066743A (en) | Solventless preparation of phthalimides | |
| SU604502A3 (en) | Method of preparing polymers containing triazine rings | |
| US3525718A (en) | Process for the production of polyamide resin and product | |
| US4138406A (en) | Manufacture of maleimides via cyclizing dehydration | |
| US5041527A (en) | Dimer for synthesis of high performance polymer matrix composites | |
| Kurita et al. | Polyaddition of bisketenimines. I. Synthesis of polyamidines from bisketenimines and diamines | |
| CN111647153B (en) | Preparation method of complex color-developing polyamide | |
| US4145524A (en) | Preparation of heterocyclic block copolymer from perfluoroalkylene oxide α, ω-diamidoximes | |
| JP2597863B2 (en) | Method for producing imide group-containing polymer produced from hindered diamine | |
| US4138392A (en) | Imide nitrogen dibenzofurans polymers | |
| JP3171635B2 (en) | Synthetic method of citraconic imide | |
| US5247057A (en) | Insitu molecular composites based on rigid-rod polyimides | |
| Ueda et al. | Synthesis of polyamide‐pyrazolones from 2, 2′‐disubstituted bis (4‐ethoxymethylene‐5‐oxazolone) and aromatic dihydrazines | |
| EP0617025B1 (en) | Triazole compounds, their intermediates, and method for production of the same | |
| Ueda et al. | Synthesis of polyphthalamides by ring‐opening polyaddition reaction of N, N′‐disubstituted bisphthalisoimides with diamines | |
| SU857162A1 (en) | Oligo-(diphenylene)-sulfides for synthesis of thermosetting polymers and their preparation method | |
| JPS62252763A (en) | Production of alkyl-substituted bismaleimide | |
| Chau et al. | Synthesis of polyamide‐quinazolinediones from 2, 2′‐disubstituted bis (1, 3, 4‐oxadiazolin‐5‐ones) and aromatic bis‐o‐amino esters | |
| SU1340584A3 (en) | Method of producing n-/4-/2-(5-methylpyrazinyl-2-carboxamido)-ethyl/-benzosulfonyl/-n-cyclohexyl-urea | |
| JP3849147B2 (en) | Process for producing benzo [1,2-d: 5,4-d '] bis-2 (3H) -oxazolone derivative |