CA1300635C - N-substituted arylcyclobutenyl-unsaturated cyclic imides - Google Patents

Abstract

ABSTRACT
The invention is a compound which comprises an un-saturated cyclic imide moiety, such as maleimide, and an aryl cyclobutene moiety, such as a benzocyclobutenyl moiety, wherein the cyclobutene moiety is fused to the aryl radical, and wherein the imide nitrogen is connected to the aryl radical by a direct bond or a bridging member. Such compounds may have the structural formula

Description

~30(~35 N-SUBSTITUTED ARYLCYCL0 .
BUTENYL-UNSATURATED CYCLIC IMIDES

This invention relates to N-substituted aryl-cyclobuteno-unsaturated cyclic imides, and to novel polyimides prepared from such compounds.
In recent years the search for high perfor-mance materials, especially high temperature-reslstant polymers, has gained momentum. In order for a material to have stability at high temperatures, it must fulfill several requirements including a high melting or softening temperature, a high modulus or rigidity, a resistance to solvent and chemical degradation, and tou~hness. The intrinsic thermal and oxidative stability of aromatic structures has long been recognized, and a variety of polymers have been made in which benzene rings are linked together by various connecting groups. Among the more stable aroma.tic polymers that fulfill the requirements of high temperature resistance are the polybenzimidazoles, the polybenzoxazoles and the polyimides. Of these polymers, the polyimides have had the most interest.

2~
,~

28,913C-F -1-~ 3~ i3S

The major difficulty encountered in the commercial development o~ these materials is that they are usually obtained in the form of a powder which cannot be readily fabricated into useful objects.
The polyimides prepared from aliphatic diamines and aromatic carboxylic acids are generally soluble and thermoplastic. Aliphatic polyimides have been prepared from bis(dienophiles) and a diene such as cyclopentadiene. Such reactions often involve gas evo-lution.
Aromatic polyimides, such as polypyromellit-imides, have a spectrum of superior properties. Those polyimides may be prepared by the reaction of an aromatic dianhydride with an aromatic diamine to give a soluble polyamic acid, which on cyclodehydration gives the insoluble desired product.
High performance plastics reduce the weight of mechanical components, and not just by virtue of their densitieQ. Their high perPormance properties allow greater design stresses, and often elements can be downsized accordingly. In recent years, aromatic polyimides have become widely accepted as premillm, high performance engineering plastics~ These resins are well-known for having excellent properties at elevated temperatures (i.e., chemical resistance) but are also costly. Historically, polyimide resins are difficult to fabricate into objects other than fibers and films.
The most common methods of manufacturing parts having the highest strength and temperature properties are hot compression-molding, machining from hot-compression molded or extruded rod, and direct forming (a process similar to the powder-metallurgy processes). Given the 28,913C-F -2-~30~)63~
_ 3 _ 64693-4007 synthetic and fabrication d~ficultie~, a new route to polyimides is desirable.
A further problem with the preparatlon of certain polyimide~ is the need for the use of catalysts, initiators or curing agents. The presence of such ~ompounds often results in the preparation of impure polymertc composition~. Further, the presen~Q of ~uch compounds often results in undesirable properties in such polymerlc compo~lt~ons. What are needed are monomers which prepare polyimlde~ whereln the polymer~ can be easily proces~ed, for exa~ple, fabr~cated into ugeful objects. What are further needed are monomers which can be polymerlzed in a manner such that no ga3 1~ evolved. What are further needed are monomers which can be poly~er~zed wlthout t~e need or catalysts, curing agents or initlators.
The inventlon 1~ a compound whlch comprlses an un-satuxated cyclic lmide moiety and an aryl cyclobute:ne moiety, wherein the cyclobutene moiety i~ fused to the aryl radlc~l, and wherein the lmide nltrogen is connected to the aryl radical by a brldglng m0~bar or a dlreGt bond.
Accordlng ~o one a~pect of the pre~ent lnven~ion there i8 pro~lded a compou~d whlch corregpond8 to the formula o ( R 1 ) ~
~(R2)2 wherein ~0~)~;35 - 3a - 64693-4007 Rl is separately in each o~curr~cea hydrocarbyl, hydrocarbylthio, hydrocarbyloxy, electron-withdrawing or electron-donating group;
R is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, hydro-carbyl, hydrocarbyloxy or hydrocarbylthio;
Y is a direct bond or a divalent organic radical; and b is an integer of from 0 to 3, inclusive; with the proviso that at least two of R are hydrogen and the further proviso that the moieties Rl, R2 and R3 do not interfere with polymerization of the compound.
According to a further aspect of the present inven-tion there is provided a compound which corresponds to the formula ~ ~ _ y - Ar (C(R )2)2 wherein Ar is a carbocyclic aromatic radical;
R is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R is separately in each occurrence hydrogen, cyano, halo, or electron-donating group;

R3 is separately in each occurrence hydrogen, a hydro-carbyl, hydrocarbyloxy or hydrocarbylthio group;

,, .
- 3a ()0635 - 3b - 64693-4007 Y is a direct bond or a divalent organic radical; and a is an integer of from 0 to 3;
with the proviso that the two carbon atoms of the (C(R2)2)2 moiety which are bound to Ar are bound to adjacent carbon atoms; the same aromatic ring of Ar; with the further proviso that at least two of R2 are hydrogen; and the further proviso that the moieties Rl, R2 and R3 do not interfere with polymerization of the compound.
According to another aspect of the present invention there is provided a monomer which corresponds to the formula ~ ~ )2 wherein Rl is separately in each occurrence an electron-with-drawing or electron-donating group;
R2 is separately in each occurrence hydrogen, a cy-: ano, an alkoxy, a halo, or an alkyl group;
R3 is separately in each occurrence hydrogen, hydro-carbyl, hydrocarbyloxy or hydrocarbylthio;
Y is a direct bond; and b is an integer of from 0 to 3, inclusive with the proviso that at least two of R2 are hydrogen with the further proviso that Rl, R2 and R3 do not interfere with polymerization : of the monomer.
Another aspect of this invention is a polyimide polymeric composition which results from the polymerization of 3b 1300~35 - 3c - 64693-4007 one or more of the above-described compounds.
The novel compounds of this invention are easily processable into useful articles. The polymerization of such compounds does not result in the evolution of gaseous or volatile by-products which can create problems in the eventual product prepared.

- 3c ,, .

~30~3~

Furthermore, in order to prepare the polymers of these monomers, there is no need for catalysts, initiators or curing agents.
In general, the compounds of this invention comprise unsaturated cyclic imides which are N-substi-tuted with arylcyclobutene moieties. In such arylcyclobutene moieties the cyclobutene ring is ~used to the aromatic radical. The nitrogen atom of the cyclic imide is connected to the aryl radical of the arylcyclobutene moiety by a bridging member or a direct bond. The cyclic imide can be substituted with hydrocarbyl, hydrocarbyloxy or hydrocarbylthio substituents. The aryl radical on the arylcyclobutene moiety can be substituted with electron-withdrawing groups, electron-donating groups, hydrocarbyl groups, hydrocarbyloxy groups or hydrocarbylthio groups. The cyclobutene ring may be sub~tituted with electron-~ithdrawing groups or electron donating groups.
The cyclic imide can be any cyclic imide moietywhich contains olefinic unsaturation, and which may be substituted in the manner described hereinbefore.
It is pre~erable that the olefinic unsaturation be adjacent to one of the carbonyl moieties of the imide functionality. In one preferred embodiment, the cyclic imide is a 5-membered heterocycle, in particular, a maleimide. Preferably, the substituents which may be on the carbon atoms of the imide ring are C1-20 alkyl~
C1 20 alkoxy, C1_20 alkylthio, C6_20 aryl, C6_20 aryloxy~ C6-20 arylthio, C7_20 alkaryl, C7 20 alkaryloxy, C7_20 alkarylthio, C7_20 aralkyl, C7_20 aralkoxy or C7_20 aralkylthio. More preferred 28,913C-F -4-~3~0~i35 substituents include Cl_20 alkyl, with C1_3 alkyl being most preferred.
~he arylcyclobutene moiety can be any aro-matic radical which has a cyclobutene ring fused to one of the aromatic rings. The term "aryl" refers herein to any aromatic radical. Aromatic as used herein refers to carbocyclic or heterocyclic rings in which 4n + 2 delocalized n elections are contained in an orbital ring. This property is also known as resonance stablization or delocalization. Preferred carbocyclic aromatic radicals include benzene, naphthalene, phenan-threne, anthracene 7 a biaryl radical, or two or more aromatic radica]s bridged by alkylene or cycloalkylene moieties. More preferred carbocyclic aromatic radicals include benzene, naphthalene, biphenyl, binaphthyl or a diphenylalkylene or a diphenylcycloalkylene compound.
The most preferred carbocyclic aromatic radical is benzene. Examples of preferred heterocyclic aromatic compounds included pyrrole, furan, thiophene, imidazole, oxazole, thiazole, pyrazole, pyridine, and pyrimidine. More preferred heterocyclic aromatic compounds are pyridine, furan, and thiophene, with pyridine being most preferred. The carbocyclic aromatic ring~ are pre~erred over the heterocyclic aromatic rings.
The aryl radical can be substituted with electron-withdrawing groups, electron-donating groups, hydrocarbyloxy groups, hydrocarbyl groups or hydrocarbylthio groups. Electron-withdrawing groups re~er herein to cyano, carboxylate, hydrocarbyl-carbonyloxy, nitro, halo9 hydrocarbylsulfinyl or hydrocarbylsulfonyl groups. Electron-donating groups refer herein to amino groups, hydroxy groups or alkyl 28,913C-F -5-13~)0~35 groups. Preferred substituents on the aryl radical include C1_20 alkyl, C1_20 alkoxy, C1_20 alkylthio, C6_ 20 aryl, C6_20 aryloxy, C6_20 arylthio, C7_20 alkaryl, C7_20 alkaryloxy, C7_20 alkarylthio, C7_20 aralkyl, C7_ 20 aralkoxy, C7_20 aralkylthio, cyano, carboxylate, hydrocar~ylcarbonyloxy, nitro, halo, hydrocarbyl-sulfinyl, amino or hydrocarbylsulfonyl. More preferred substituents on the aryl radical include C1_20 alkyl, halo, nitro or cyano. The most pre~erred substituents on the aryl moiety include Cl_3 alkyl, halo, nitro or cyano.
The cyclobutene ring may be substituted with electron-withdrawing groups or electron donating groups, wherein electron-withdrawing groups and electron-donating groups are described hereinbefore.
Preferred substituents on the cyclobutene ring are cyano, carboxylate, hydrocarbylcarbonyloxy, nitro, halo, hydrocarbylsulfonyl or hydrocarbylsulfinyl. More preferred substituents include halo, nitro or cyano groups; with cyano groups being most preferred.
The bridging member can be a divalent organic radical which is bonded to the nitrogen of the cyclic imide and the aryl radical o~ the arylcyclobutene moiety. The divalent organic radical use~ul as a bridging member is any divalent organic radical which i9 capable of being bonded to both the nitrogen of a cyclic imide and an aryl radical. The divalent organic radical i5 preferably a hydrocarbylene, hydrocarbylene-amido, hydrocarbylenecarbonyloxy, hydrocarbyleneoxy, hydrocarbylenethio, hydrocarbylenesulfinyl or hydrocar-bylenesulfonyl radical. More preferred divalent organic radicals are alkylene, arylene 9 alkylene-bridged polyarylene, cycloalkylene-bridged polyarylene, 28,913C-F -6-` ~0~635 alkyleneamido, aryleneamido, alkylene-bridged polyaryleneamido, cycloalkylene-bridged polyaryleneamido, alkylenecarbonyloxy, arylenecarbonyloxy, alkylene-bridged polyarylene-carbonyloxy, cycloalkylene-bridged polyarylene-carbonyloxy, alkyleneoxy, aryleneo~y, alkylene-bridged polyaryleneoxy, cycloalkylene bridged polyaryleneoxy, alkylenethio, arylenethio, alkylene-bridged polyarylenethio, cycloalkylene-bridged polyarylenethio, alkylenesulfinyl, arylenesulfinyl, alkylenebridged polyarylenesulfinyl, cycloalkylene-bridged polyarylenesulfinyl, alkylenesulfonyl, arylenesulfonyl, alkylene-bridged polyarylenesulfonyl or cycloalkylene-bridged polyarylenesulfonyl. Even more preferreddivalent organic radicals include alkylene, arylene, alkylenecarbonyloxy, arylenecarbonyloxy, alkyleneamido, aryleneamido, alkyleneoxy, aryleneoxy, alkylenethio or arylenethio. Most preferred divalent organic radicals include alkylene and aryiene radicals.
Preferably, the aryl moiety and cyclic imide are connected by a direot bond or a bridging member which compriqes an alkylene, arylene, alkylene-bridged polyarylene or cycloalkylene-bridged polyarylene; and more preferably a direct bond or a bridging me!mber which comprises an alkylene or arylene moiety. Most pre~erably the cyclic imide nitro~en and the aryl radical are connected by a direct bond.
3o Preferred N-substituted arylcyclobutenyl cyclic imideq correspond to the ~ormula 28,913C-F -7-" ~OO~i35 ~G~

X ~I~Y-Ar/ ~ C(R2)2)2 \C/ (Rl)a wherein Ar is an aromatic radical;
Rl is separately in each occurrence a hydro-carbyl, hydrocarbyloxy, hydrocarbylthio, electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen or an electron-withdrawing group;
X is an alkenylene moiety which can be sub-stituted with one or more hydrocarbyl, hydrocarbyloxy or hydrocarbylthio groups;
Y is a direct bond or divalent organic moi-ety; and a is an integer of between 0 and 3.
More preferred N-substituted arylcyclobu tenyl-unsaturated cyclic imides include those which correspond to the formula 28,913C-F -8-g R3 ~

N-Y-Ar (C(R2)2)2 wherein Ar is an aromatic radical;
R1 is separately in each occurrence a hydro-carbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately. in each occurrence hydrogen or an electron-withdrawing group;
R3 is separately in each occurrence hydrogen, a hydrocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and a is an integer of between 0 and 3.
In an even more preferred embodiment, the N-substituted arylcyclobutenyl-unsaturated cyclic imide corresponds to the formula 28,913C-F -9-~3~ 3S
--1 o--9 ~ )2 wherein R1 is separately in each occurrence a hydro-carbyl, hydrocarbylthio, hydrocarbyloxy9 electron-withclrawing or electron-donating group;
R2 i9 separately in each occurrence hydrogen or an electron-withdrawing group;
R3 is separately in each occurrence hydrogen, hydrocarbyl, hydrocarbyloxy or hydrocarbylthio;
Y is a direct bond or a divalent organic radical; and b is an integer of between 0 and 3, inclu~ive.
In the above formulas, R1 i9 preferably C1~2~
alkyl, C1_20 alkoxy, C1_20 alkylthio, C6_20 aryl, C6_20 aryloxy~ C6-20 arylthio, C7_20 alkaryl, C7 20 alkaryloxy, C7_20 alkarylthio, C7_20 aralkyl, C7_20 3 aralkoxy, C7_20 aralkylthio, cyano, carboxylate, hydrocarbylcarbonyloxy, nitro, halo, hydrocarbylsul-finyl, hydrocarbylsulfonyl or amino. R1 is more pref-erably C1_20 alkyl, halo, nitro or cyano. Most prefer-ably R1 is C1-3 alkyl, halo, nitro or cyano.

287913C-F -lQo ~ 306~5 "

R2 is preferably hydrogen, cyano, carboxylate, hydrocarbylcarbonyloxy, nitro, halo, hydrocarbyl-sul~onyl hydrocarbylsulfinyl, alkyl, amido, hydrocarbyloxy. R2 is more preferably hydrogen, halo, nitro or cyano. R2 is even more preferably hydrogen or cyano and most preferably hydrogen.
R3 is preferably hydrogen, C1_20 alkyl7 C1_20 alkoxy, C1-20 alkylthio, C6_20 aryl, C6_20 aryl-oxy, C6 20 arylthio, C7_20 alkaryl~ C7_20 alkaryloXY~ C7-20 alkarylthio, C7_20 aralkyl~ ~7-20 aralkoxy or 7-20 aralkylthio. R3 is more preferably hydrogen or C1_20 alkyl. R3 is even more preferably hydrogen or C1_3 alkyl and most preferably hydrogen.
In the above formulas, Y is preferably a direct bond, a hydrocarbylene, hydrocarbyleneamido, hydrocarbylenecarbonyloxy, hydrocarbyleneoxy, hydro-carbyleneamino, hydrocarbylenecarbonyl, hydrocarbyl-enethio, hydrocarbylenepolythio, hydrocarbylenesul-finyl or hydrocarbylenesulfonyl. Y is more prefer-ably a direct bond, alkylene, arylene, alkylene-bridged polyarylene, cycloalkylene-bridged polyarylene, alkyleneamido, aryleneamido, alkylenecarbonyloxy, arylenecarbonyloxy, arylenecarbonyl, alkylenecarbonyl, aryleneoxy, alkyleneoxy, aryleneamino, alkyleneamino, alkylenethio, alkylenepolythio, arylenethio, arylenepolythio, arylenesulfinyl, alkylenesulfinyl, arylenesulfonyl or alkylenesulfonyl. Y is most preferably a direct bond, alkylene or arylene.
In the formulas described hereinbefore, Ar is preferably a benzene, naphthalene, phenanthrene, anthracene or biaryl radical, or two or more aromatic radicals bridged by alkylene moieties. Ar is more 28,913C-F -11-preferably benzene, naphthalene, biphenyl, binaphthyl or a diphenylalkylene. Ar is more preferably a benzene radical.
Hydrocarbyl means herein an organic radical containing carbon and hydrogen a~oms. The term hydro-carbyl includes the following organic radicals:
alkyl,alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aliphatic and cycloaliphatic aralkyl and alkaryl. Ali-phatic re~ers herein to straight- and branched-, and saturated and unsaturated, hydrocarbon chains, that is, alkyl, alkenyl or alkynyl. Cycloaliphatic refers herein to saturated and unsaturated cyclic hydrocarbons, that is, cycloalkenyl and cycloalkyl.
The term aryl re~ers herein to biaryl, biphenylyl, phenyl, naphthyl, phenanthranyl, anthranyl and two aryl groups bridged by an alkylene group. Alkaryl refers herein to an alkyl-, alkenyl- or alkynyl-substituted aryl substituent wherein aryl i9 as de~ined hereinbeYore. Aralkyl means herein an alkyl, alkenyl or alkynyl group substituted with an aryl group, wherein aryl is as defined hereinbefore. Cl_20 alkyl includes straight- and branchad-chain methyl, ethyl, propyl, butyl, pen~yl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, perltadecyl, hexadecyl, heptadecyl, octadecyl,-nonadecyl ancl eicosyl groups. Cl_5 alkyl includes methyl, ethyl, propyl, butyl and pentyl.
3o Cycloalkyl re~ers to alkyl groups containing one, two, three or more cyclic rings. Cycloalkenyl re~'ers to mono-, di- and polycyclic groups containing one or more double bonds. Cycloalkenyl also refers to 28,913C-F -12--cycloalkenyl groups wherein two or more double bonds are present.
Hydrocarbylene herein refers to a divalent hydrocarbon radical and is analogous to the hydrocarbyl radicals described hereinbefore with the single differ-ence that the hydrocarbylene radical is divalent.
Hydrocarbyleneamido refers herein to a divalent radical wherein a hydrocarbylene radical is bonded to an amido group, and corresponds to the for-mula o wherein R4 is a hydrocarbylene radical and R5 is hydro-gen or a hydrocarbyl radical.
Hydrocarbyleneoxy refers herein to a divalent radical in which a hydrocarbylene radical is bonded to a divalent oxygen atom and corresponds to the formula -R4-o~ wherein R4 i9 as defined hereinbefore.
Hydrocarbylenecarbonyloxy refers to a hydro-carbylene moiety which is bonded to a carbonyl moiety which is further bonded to a divalent oxygen atom and corresponds to the formula R4-Co~

wherein R4 is as defined hereinbeforeO

28,913C-F -13-0~3S

Hydrocarbylenethio refers herein to a radical in which a hydrocarbylene radical is further bonded to one or more sulfur moieties and corresponds to the formula -R4-(S)p- wherein R4 is as hereinbefore defined, and wherein p is between 1 and 3.
Hydrocarbyleneamino refers herein to a hydrocarbylene radical bonded to an amino moiety and generally corresponds to the formula wherein R4 and R5 are as defined hereinbefore.
Hydrocarbylenesulfinyl refers herein to a hydrocarbylene moiety bo~ded to a sulfinyl moiety and generally corresonds to the formula wherein R4 is as hereinbefore defined.
Hydrocarbylenesulfonyl ~enerally corresponds to a radical in which a hydrocarbylene radical is bonded to a sul~onyl radical and corresponds to the formula 2~,913C-F -14-~30()~i3S

o wherein R4 i~ as hereinbefore defined.
Wherein the bridging member is a hydrocarbyl-eneamido, hydrocarbyleneoxy7 hydrocarbyleneamino, hydrocarbylene~hio, hydrocarbylenecarbonyloxy moiety, the amido, amino, oxy, thio, sul~inyl or sulfonyl moiety is preferably bonded to the aryl portion of the arylcyclobutene.
Examples of preferred N-substituted benzocy-clobutenyl maleimides include N-benzocyclobutenyl male-imide, N-benzocyclobutenylmethyl maleimide, N-benzocy-clobutenylethyl maleimide, N-benzocyclobutenylpropyl maleimide, N-benzocyclobutenylbutyl maleimide, N-ben-zocyclobutenylpentyl maleimide, N-benzocyclobutenyl-hexyl maleimide, N-benzocyclobutenylphenyl maleimide, N-benzocyclobutenylbiphenyl maleimide, N-benzocyclobu-tenylamidomethyl maleimide, N-benzocyclobutenylamido-ethyl ma.leimide, N-benzocyclobutenylamidopropyl male-imide, N-benzocyclobutenylamidobutyl maleimide, N-ben-zocyclobutenylamidopentyl maleimide, N-benzocyclobuten-ylamidohexyl maleimide, N-benzocyclobutenylamidophenyl maleimide, N-benzocyclobutenylamidobiphenyl maleimide, : N-benzocyclobutenyloxycarbonylmethyl maleimide, N-benzocyclobutenyloxycarbonylethyl maleimide 9 N-benzocyclobutenyloxycarbonylpropyl maleimide, N-benzocyclobutenyloxycarbonylbutyl maleimide, N-; 35 benzocyclobutenyloxycarbonylpentyl maleimide, N-benzocyclobutenyloxycarbonylhexyl maleimide, N-28,913C-F -15-~3~)~)635 .--16--benzocyclobutenyloxycarbonylphenyl maleimide, N-benzocyclobutenyloxycarbonylbiphenyl maleimide, N-ben-zocyclobutenylthiomethyl maleimide, N-benzo-cyclobutenylthioethyl maleimide, N-benzocyclo-butenylthiopropyl male-imide, N-benzocyclo-butenylthiobutyl maleimide, N-benzocyclo-butenylthiopentyl maleimide, N-benzocyclo-butenylthiohexyl maleimide, N-benzocyclo-butenylthiophenyl maleimide, N-benzocyclo-butenylthiobiphenyl maleimide, N-benzocyclo butenyloxymethyl maleimide, N-benzocyclobutenyloxyethyl maleimide, N-benzocyclobutenyloxypropyl maleimide, N-benzocyclobutenyloxybutyl maleimide, N-benzocyclo-butenyloxypentyl maleimide, N-benzocyclobutenyloxyhexyl maleimide, N-benzocyclobutenyloxyphenyl maleimide, N-benzocyclobutenyloxybiphenyl maleimide.
The arylcyclobutene moieties can be prepared by several synthesis schemes.
In one synthesis scheme, an alkyl-substituted aromatic compound which is further substituted with an aryl deactivating substituent is chloroalkylated in a position ortho to the alkyl group. In the preferred embodiment wherein the aromatic compound is benzene, the starting material corresponds to the following for-mula ~3o 28,913C-F -16-, 3 ~ ~ 6 3 .

(R2)2 lH

(R1 wherein R1 and R2 are defined hereinbefore; R9 is any aryl deactivating substituent; and c is an integer of o, 1, 2, or 3. The alkyl N-substituted aromatic compound is chloroalkylated by contacting the alkyl aromatic compound with a chloroalkylating agent and thionyl chloride in the presence of an iron chloride cataly~t so a~:to result in a product which contains a chloroalkyl group ortho to the alkyl substituent. In the embodiment wherein the aromatic compound is a benzene ring, the product corresponds to the formula (R2)2 CH

(R~ C(R2)2-Cl .

wherein R9 i9 a hydrocarbyloxycarbonyl, carboxamide, hydrocarbylcarbonyl, carboxylate, halocarbonyl, 28,913C F -17-3C~0635 nitrile, nitro, sulfone or sulfoxide group. R9 is more preferably a halo or hydrocarbyloxycarbonyl group, with hydrocarbyloxycarbonyl being the most preferred group.
Preferably c i9 0 or 1, most pre~erably 0.

In this process the chloroalkylating agent is preferably chloromethyl methyl ether, although other chloroalkylating agents such as bis(chloromethyl) ether could be used. At least a 2:1 molar excess of the chloroalkylating agent to the alkyl-substituted aromatic compound is needed. It is preferable to use between a 6:1 and 3:1 ratio of chloroalkylating agen~
to alkyl aromatic compound. The catalyst is ferric chloride (FeCl3) while the cocatalyst is thionyl chloride. The catalyst can be present in between 0.1 and 1.0 mole per mole of alkyl aromatic. More preferably between 0.2 and 0.4 mole of catalyst are present for each mole of alkyl aromatic compound.
Preferably between 0.1 and 1.0 mole of thionyl chloride per mole of alkyl aromatic is used, more preferably between 0.2 and 0.4 mole per mole of alkyl aromatic.
This process can be performed at a tempera-ture of between 40C and 80C, preferably 40C and 60C.
Below 40C, the reaction rate is low. The boiling point of some of the components of the reaction mixture starts at 80C.
3~ This process can be done by contacting the alkyl aromatic compound with the chloromethylating agent, catalyst and cocatalyst in a suitable solvent.
Suitable solvents include chlorinated hydrocarbon solvents. Thereafter the reaction mixture is heated to the appropriate temperature.

28,913C F -18-0 6~ 5 The product can be recovered by quenching the reaction mixture with alcohols or water to inactivate the chloroalkylating agents remaining, stripping off the volatiles and washing out the catalyst with water.
The product thereafter is recovered by distillation.
..
The ortho chloroalkylated alkyl aromatic compounds can be converted to aromatic compounds with cyclobutene rings ~used thereto, by pyrolysis. This is achieved by contacting the ortho chloroalkylated alkyl aromatic compound with at least 2 times its weight of a suitable diluent, and thereafter passing the mixture through a reactor at a temperature of 550C or greater and a pressure of between about atmospheric and 25 mm of mercury. Suitable diluents are generally substituted aromatic compounds which are inert to the chloromethylated alkyl aromatic compound and are stable at pyrolysis temperatures. Examples of suitable diluents are benzene, toluene, xylenes, chlorobenzenes, nitrobenzenes, methylbenzoates, phenyl acetate or diphenyl acetate. Preferred diluents are the xylenes.
Preferable temperatures are between 700C and 750C.
Preferable pressures are between 35 and 25 mm o~
mercury. In a preferred embodiment, the reaction mixture i9 pa~sed through a hot tube packed with an inert material 5 for example, quartz chips or stainless steel helices. The product can be recovered by distillation. The product wherein the aromatic 3 compound is benzene corresponds to the formula 28,913C-F -19-;35 .~ .

~ R2 ) 2 wherein R1, R2, R9 and c are as hereinbefore defined.

In the preferred embodiment wherein R9 is a hydrocarbyloxy carbonyl moiety, the hydrocarbyloxy carbonyl moiety can be converted to a carboxylate moi-ety by contacting the substituted (arylcyclobutene) compound with at least a molar equivalent o~ alkali metal hydroxide in an alkanol-water solvent system. In the embodiment wherein the aromatic radical is benzene, the product corresponds to the formula ~ ~2)2 HOC
o Thereafter the carboxylate-substituted (aryl-cyclobutene) compound can be converted to an acid chlo-ride by contacting the carboxylate-substituted (arylcy-28,913C-F -20-,..

) i35 clobutene) compound with thionyl chloride and refluxing at 70C to 80C. The acid halide-substituted (arylcyclobutene) so formed can be used to prepare the novel monomers of this invention, as described hereinafter. In the embodiment wherein the aryl radical is a benzene ring, the product ~orresponds to the formula (R1 )~R2)2 ClC
o In an alternative synthesis, an aryl compound with ortho dibromomethyl groups can be converted to a 1,2-diiodoarylcyclobutene, by contacting the aryl com-pound substituted with ortho dibromomethyl moieties with an alkali metal iodide in an alkanol solvent at reflux ~o a~ to form the diiodoarylcyclobutenes. The product can be recovered by filtering, evaporating the filtrate and recrystallizing the product. In the embodiment wherein the aryl radical is a benzene radical, the starting material corresponds to the formula 28,913C-F -21-1~ 35 (R1)G ~ HBr2 ~ CHBr2 and the iodobenzocyclobutene corresponds to the formula ( R 1 ) G ~ I

The 1,2-diiodoarylcyclobutenes can be converted to arylcyclobutenes by dissolving the 1,2-diiodo-arylcyclobutenes in an alcohol solvent, preferably methanol or ethanol and contacting the solution with an alkali metal hydroxide in the presence of a palladium-on-carbon catalyst and H2 gas at a temperature of 20C
3 to 30C. In general, at least between about 2 and 4 moles of alkali metal hydroxide per mole of 1,2-diiodoarylcyclobutene is used. Preferably, between 50 and 200 psi (344.7 kPa and 1379 kPa) of hydrogen gas is u~ed. The arylcyclobutenes prepared in this manner can be recovered by distillation. In the embodiment 28,913C-F -22-~L30~3~3~i wherein the aryl radical is a benzene radical, the product corresponds to the formula (R1 )~ )Ll The arylcyclobutene is thereafter brominated.
In this process, the arylcyclobutene is dissolved in acetic acid and contacted with a brominating agent of pyridinium hydrobromide perbromide in the presence of mercuric salts, for example, mercuric acetate, at a temperature of between 20C and 50C. The brominated product can be recovered by extraction and distillation. In the embodiment wherein aryl radical is benzene, the product corresponds to the formula (R1) Br The brominated arylcyclobutene can there~after be carbonylated to prepare a hydrocarbyloxy carbonyl-substituted arylcyclobutene. This carbonylation is achieved by dissolving the brominated arylcyclobutene in an alkanol solvent~ and thereafter contacting the solution with carbon monoxide under pressure in the presence of a palladium catalyst, wherein the palladium is in the zero valence state, in the further presence of an acid acceptor under conditions such that the 28,913C-F -23-:

` ~0~)~;35 brominated arylcyclobutene compound undergoes car-bonylation. Preferred catalysts are palladium acetate with a cocatalyst of triphenyl phosphine, palladium triphenyl phosphine tetrakis, andbis(triphenyl phosphine) palladium chloride complex. The acid acceptor is generally a tertiary amine. In general, the reaction vessel is pressurized with carbon monoxide to a pressure of between atmospheric and 3000 psi (20,684 kPa), preferred pressures are between 600 and 1000 psi (4136 and 6895 kPa).
This process is preferably run at a tempera-ture of between 100C and 140C, most preferably between 120C and 130C. The hydrocarbyloxycarbonyl arylcyclobutene can be recovered by filtering off the catalyst, washing away the acid scavenger with a 10 percent strong acid solution, stripping off the solvent and distilling the product to puri~y it. To prepare a carboxamide-substituted arylcyclobutene, a primary or secondary amine is substituted for the alcohol solvent.
In the embodiment wherein the aryl radical is a benzene radical, the process corresponds to the following equation:

(R1)C--~ +R100H + N(R6)3~R1)C~

wherein R1 and c are as hereinbe~ore de~ined and R6 and R10 are hydrocarbyl moieties. The hydrocarbyloxy-carbonyl-substituted or carboxamide-substituted arylcyclobutenes can thereaYter be acidified and 28,913C-F -24-converted to acid chlorides by the process described hereinbefore.
In another preparation of an arylcyclobutene, the reaction may ~ollow that reported by Skorcz and Kaminski, Or~. Syn., 48, pages 53-56 (1968). In a typical preparation, an alkyl cyanoacetate is added to - a solution o~ sodium metal in ethanol followed by the addition of an ortho-halomethylaryl halide. The alkyl 2-(o-halomethylaryl)cyanoacetate is isolated and treated with aqueous sodium hydroxide. Subsequent acidi~ication results in the cyanoacetic acid derivative. That derivative is placed into N,N-dimethylformamide and is refluxed to form the 3-(o- -halomethylaryl)propionitrile derivative which is isolated and added to a suspension of sodamide in liquid ammonia. ~fter an appropriate reaction time, ammonium nitrate is added and the ammonia allowed to evaporate. The cyanoarylcyclobutene is isolated by ether extraction and purified by ~ractional distilla-tion under reduced pressure.
Substituted arylcyclobutenes can be prepared by the same technique by using the appropriately substi-tuted reactants, such as an alkyl or alkoxybenzyl halide. Also substituents can result ~rom using an alkyl haloacetate or a dialkylmalonate.
In another preparation based on the paper by Matsura et al., Bull. ChemO Soc. Jap., 39, 1342 (1966), o-a~inoaryl carboxylic acid is dissolved in ethanol and hydrochloric acid added. Isoamylnitrite is slowly added to the cold stirred solution and diethyl ether is then added. The product, aryldiazonium-2-carboxylate hydrochloride, is filtered. That product is placed in 28,913C-F -25-3~;

a solvent, preferably ethylene dichloride, and acrylonitrile and propylene oxide is added to the stirred mixture which is then heated under nitrogen until the reaction is complete. After cool-ing, the mixture is filtered and the product, l-cyanoarylcyclo-butene, is isolated by fractionally distilling the filtrate under reduced pressure.
Amounts of reactants, reaction parameters and other details can be found in the cited article, the examples of this application, or can be easily deduced therefrom.

In the next sequence of reactions, the cyanoarylcyclo-butene or substituted derivative is nuclear substituted. In one preparation, the cyanoarylcyclobutene is added slowly to a cold solution of sodium nitrate in concentrated sulfuric acid to form 5-nitro-1-cyanoarylcyclobutene. That nitro compound is isolated, dissolved in ethanol and reduced by hydrogenation over a palladium on carbon catalyst. The isolated product is 5-amino-1-cyanoaryl-cyclobutene. In the preferred embodiment where the aryl radical is benzene, the product corresponds to the formula N 2 ~\ ~ CN

(R )c ~ (R2)2 Cyclobutapyridines are prepared by the pyrolysis of 4-pyridyl propargyl ether at 550C. See J.M. Riemann et al.
Tetrahedron Letters, No. 22, pp. 1867-1870 (1977).

~ ;

0~ 5 Alternatively, a pyridine-4-carbonitrile with an alkyl substituent on the carbon atom adjacent to the nitrile iq reacted with sodium azide and ammonium chloride in N,N-dimethylformamide to prepare a 5(alkyl-4-pyridyl)-tetrazole. The 5(alkyl-4-pyridyl)tetrazole i9 pyrolyzed at about 600C to prepare a cyclobutapyridine.
See. W. D. Crow et al. Australian Journal of Chemistry 1741 et seq. (1975).
Amino cyclobutapyridines are prepared by reacting a cyclobutapyridine with sodamide (NaNH2) in N,N-dimethylaniline solvent at 110C. A hydroxycyclo-butapyridine is prepared by reacting one mole of an aminocyclobutapyridine with one mole of sodium nitrite and two moles of sulfuric acid in water at 0C for a period of time and thereafter warming to 50C. Halo-substituted cyclobutapyridine i9 prepared by reacting a hydroxypyridine in thionyl at reflux either neat or in solution, for example, thionyl chloride or thionyl bromide, in N,N-dimethylformamide solvent.
The N-substituted arylcyclobutenyl-unsaturated cyclic imides of this invention wherein the bridging member is a direct bond can be prepared by the fol-lowing method. An unsaturated cyclic anhydride is contacted ~ith an amine-substituted arylcyclobutene under conditions qo as to form an N-arylcyclo-butenylamido alkenoic acid. Such acid can thereafter be dehydrated to cyclize ~he amido alkenoic acid into a cyclic imide ring and form the N-sub-stituted arylcyclobutenyl-unsaturated cyclic imide.
The formation of the arylcyclobutenyl amido alkenoic acid is achieved by reacting an unsaturated cyclic anhydride with an amine-substituted arylcyclo-28,913C-F -27-;35 butene. This reaction is exemplified in one preferred embodiment wherein the anhydride is maleic anhydride and the arylcyclobutene is 5-aminobenzocyclobutene, and is illustrated by the following equation:

NH ~

O O

lC
The cyclic anhydride and amino~substituted arylcyclobutene are contacted in a suitable solvent at a temperature of between -40C and 100C. Suitable solvents include aliphatic hydrocarbons, aromatic hydrocarbons, ethers and halogenated hydrocarbons. It is preferred to run the process under an inert atmosphere. It is also preferred to use freshly sublimed anhydride as any impurities in the anhydride can result in very poor yields. It is also preferred to use at least`a 5 percent excess of anhydride so as to drive the reaction to completion with respect to the amino-substituted arylcyclobutene compound.
Preferred temperatures are between 0C and 50C
with between 20C and 25C being most preferred.
The N-arylcyclobutenylamido alkenoic acid can thereafter be dehydrated by one of two methods. In the preferred embodiment, the N-arylcyclobutenylamido alkenoic acid is contacted with a dehydrating agent in 28,913C-F -28-j35 an aprotic reaction medium in the presence of a nickel II salt catalyst. In general, the reaction medium is an aprotic solvent and can include ketones, ethers, amides or aliphatic halogenated hydrocarbons.
Preferred reaction media include the ketones, with acetone being most preferred. The dehydrating agents include anhydrides, carbodiimides and isocyanates; with the anhydrides being preferred and acetic anhydride being most preferred.
The catalyst is any nickel II salt with nickel II acetate being most preferred. In general, between 1 and 5 percent of the catalyst is useful. It is preferable to run this process in the presence of an aprotic base such as a carbonate or tertiary amine, preferably a tertiary amine. In general, between 20 and 200 mole percent of a tertiary amine is used, with between 100 and 150 mole percent being preferred, wherein mole percentages are based on the starting N-arylcyclobutenylamido alkenoic acid. The mole ratio of the dehydrating agent to the N-arylcyclobutenylamido alkanoic acid is between 4:1 and 1:1, preferably between 1.5:1 and 1:1.
It is preferred to run this process under an inert atmosphere. Temperatures which are useful are those at which the dehydration takes place. Preferable temperatures are between -20C and 100C, with between 15C and 25C being most preferred.
In this reaction, the N-arylcyclobutenylamido alkenoic acid is not ~oluble in the reaction medium but the cyclic imide product is solubleO The reactant is slurried in the reaction media and exposed to the reaction conditions described. The completion of the 28,913C-F -29-S

reaction is noted by dissolution of the reactants indicating formation of products.
In an alternative procedure, the N-arylcyclo-butenyl amido alkenoic acid can be dehydrated bydispersing the compound in a glacial acetic acid reaction media in the presence of an alkali or alkaline earth metal acetate salt, and heating the reaction mixture to a temperature at which the dehydration takes place to form the cyclic imide rings. Generally, a sufficient amount of alkali or alkaline earth metal acetate salt to cause complete dehydration is suitable.
Preferably, at least an equimolar amount of alkali or alkaline earth metal acetate salt is used, most preferably an excess of 5 mole percent. The process can be run at any temperature at which the dehydration takes place, preferable temperatures are between 50C
and 140C, with between 100C and 120C being most preferred. Completion of the reaction is indicated by dissolution of the product.
In both instances, the product can be reco~-ered by washing with water and thereafter an aqueous solution o~ an inorganic baqe.
To prepare an N-substituted arylcyclobu- tenyl cyclic imide with a hydrocarbylene amido, hydro-carbyleneoxy or hydrocarbyleneoxycarbonyl bridge, an unsaturated cyclic anhydride is reacted with a hydro-carbon substituted with amino and carboxyl moieties, for the hydrocarbylene amido-bridged species, or a hydrocarbon substituted with amino and hydroxyl moi-eties, for the hydrocarbyleneoxy and hydrocarbylene-28,913C-F -30-~3~6~5 oxycarbonyl-bridged species, to prepare an amido alka-noic acid wherein the amido nitrogen is substituted with a carboxy-substituted hydrocarbyl or hydroxy-sub-stituted hydrocarbyl moiety. This reaction can be per-formed at a temperature of between -40C and 100C in a suitable solvent. Suitable solvents include aliphatichydrocarbons, aromatic hydrocarbons, ethers and halogenated hydrocarbons. It is preferred to run the process under an inert atmosphere. It is preferred to use freshly sublimed anhydride as any impurities can result in very poor yields. It is preferred to use at least a 5 percent excess of anhydride so as to drive the reaction to completion.
In the embodiment wherein the anhydride is maleic anhydride, these reactions are exemplified by the following equations 28,913C-F -31-L3~ 5 O O ' ' R3 ~ R3 ~

O + NH2-R4-CoH~ ¦ NH2-R4-CoH
R3 ~ R3 ~ C /

O O

and O O
R3 ~ R3 ~
\ I \~H-R4-oH
O + NH2-R4-oH D- l 1 R3 ~ R3 ~ C-OH
O

wherein R3 i9 as hereinbefore defined and R4 is a hydrocarbylene radical.
The amido alkenoic acid can be dehydrated using one of the two dehydration methods described hereinbefore so as to prepare a N-substituted cyclic imide wherein the substituent is a N-hydrocarbylcar-bonyloxycarbonyl cyclic imide, or a N-hydrocarbylcar-bonyloxy cyclic imide. In the embodiment wherein the N-substituted amido alkenoic acid was derived ~rom 28,913C-F -32-~L3t~6~5 maleic anhydride, this reaction is exempli~ied by the ~ollowing equations O O
R3 ~ R3 ~ , ' \ 0 00 ` / 00 \ ~- " " _Q~t ~ " ,.
~ NH-R4-coH ~ R5CoCR5 t-amine , ~j-R4-cocR5 o and ,, +H20 ~ R5-CoH

O O

R3 ~ ~
" " cat _ ,-NH-R4-oH + R5CoCR5 t-amine N-R4-oCR5 , \ , \
R3 C-OH R3 ~ .

.
o +H20 + R5-CoH

wherein R3 and R4 are as hereinbefore defined and R5 is a hydrocarbyl moiety.

28,913C-F -33-- 130~)635 .

The N-hydrocarbylcarbonyloxycarbonyl cyclic imide is converted to a hydrocarbylene amido-bridged N-substituted arylcyclobutenyl cyclic imide by reacting the N-hydrocarbylcarbonyloxycarbonyl cyclic imide with an amino-substituted arylcyclobutene in the presence of a tertiary amine. ThiS process can be accomplished~by contacting the starting reactants in a chlorinated ali-phatic hydrocarbon solvent at 0C with agitation under an inert atmosphere. This process iS exemplified by the following equation ~ N-~4-CoCRS + ~ ~ (R6)3-N~

lt 1' R3. ~
~ N-R4-CN/ ~ ~ ~ +R5CoH-N-(R6)3 2( 0 wherein R4 and R5 are as herelnbefore defined, and R6 is a hydrocarbyl radicalO

28,913C-F -34-- 13~06~S

To prepare a hydrocarbyleneoxy or hydrocar-byleneoxycarbonyl-bridged N-substituted arylcyclo-butenyl cyclic imide, the N-hydrocarbylcarbonyl-oxyhydrocarbyl cyclic imide is hydrolyzed to prepare a N-hydroxyhydrocarbyl cyclic imidec The hydrolysis is usually run in an aqueous/alkanol solvent system in the presence of an acid or base catalyst at between room temperature and reflux of the solvent mixture (20C to 60C). This reaction is exemplified by the following equation ~ W-R~-oC~5 +~2 ~ N-R4-o~ + ~5CoH

wherein R3, R4 and R5 are as hereinbefore defined.
To prepare the hydrocarbyleneoxycarbonyl-bridged N-substituted arylcyclobutenyl cyclic imides, the N~hydroxyhydrocarbyl cyclic imide is reacted with a chlorocarbonyl-substituted arylcyclobutene. In prac-tice, the N-hydroxyhydrocarbyl cyclic imide is dis-solved in a chlorinated aliphatic hydrocarbon solvent to which is added a tertiary amine, which functions as an acid acceptor, and thereafter the chlorocarbonyl-substituted arylcyclobutene in a chlorinated aliphatic hydrocarbon is added slowly to the mixture. This is 2~ preferably done at 0C in an inert atmosphere. It is 28,913C-F -35-~00~35 preferred to stir the reaction mixture for a period of time at 0C after the addition is complete. This reaction is exemplified by the following equation R3 ~ 0 \~ N-R4 OH + ClC~

R3 ~ ~ ¦ I (R6)3-N- -R3 ~

~ N-R4-oC - ~ + (R6)3-N HCl 1( 0 wherein R3, R4 and R6 are as hereinbefore defined.

The hydrocarbyleneoxy-bridged N-substituted arylcyclobutenyl cyclic imides can be prepared from th-e N-hydroxyhydrocarbyl cyclic imide in the following man-ner. The N-hydroxyhydrocarbyl cyclic imide is reacted with p-toluene sulfonyl chloride and pyridine to pre-pare a cyclic imido hydrocarbyl p-toluene sulfonate.
Either excess pyridine or methylene chloride are used as the solvent. The reactants are contacted in equi-molar amounts, unless pyridine is the solvent, at a temperature of between 0C and 25C. This reaction is exemplified by the following equation 28,913C-F -36-` ~3()0~5 ~ N-~4-oH + CH3 ~ 502Cl + ~ N ~

o o ~ N-R4-o-so2 ~ CH3 + ~ N-HCl O

wherein R3 and ~ are as hereinbefore defined.
The ayclic imido hydrocarbyl p-toluene sul-fonate is contacted with a hydroxy-substituted arylcy-clobutene in the presence of a four to five molarexcess of an alkali metal carbonate (~uch as potassium carbonate) based on the sulfonate, in a N,N-dimethyl formamide solvent, to prepare a hydrocarbyloxy-bridged N-substituted arylcyclobutenyl cyclic imide. This reaction takes place at temperatures of between 20C and 140C. This process is exemplified by the ~ollowing equation 28,913C-F -37-1:~00~35 N-R4-0-502 ~ H0 ~ ¦ + 4-5 E2C03 o o ~ ~W-F~4-o~=1 0 s +H2 wherein R3 and R4 are as hereinbefore defined.
The hydrocarbylene amino-bridged N-substi-tuted arylcyclobutenyl cyclic imides can be prepared by the ~ollowing procedure. An amino-substituted aryl-cyclobutene is reacted with about an equimolar amount of a hydrocarbon substituted with aldehyde and nitro moieties; in the presence o~ between about 0.3 to 1.5 moles of sodium cyanoborohydride in a methanolic sol-vent at 20C to 25C. The product is nitrohydrocarbyl amino-substituted arylcyclobutene. The process can be exemplified by the following equation 28,913C-F -38-No2-R4-CH + NHR7 ~ NaBH3CN
.

No2-R4-CH2NR7 ~

wherein R4 15 as hereinbefore defined and R7 is hydro-gen or a hydrocarbyl moiety. The nitro moiety on the nitrohydrocarbyl amino-substituted arylcyclobutene is reduced to an amine moiety by contacting with an excess of metallic zinc in a concentrated hydrochloric acid solution at between 20C and reflux. The product corresponds to the formula wherein R4 is as hereinbefore defined. The aminohy-drocarbyl amino-substituted arylcyclobutene is there-after reacted with an unsaturated cyclic anhydride to prepare a hydrocarbylene amino-bridged N-arylcyclo-28,913C-F -39-~30~
, butenyl amido alkenoic acid. The conditions for this reaction are as described hereinbefore for the reaction of an amino-substituted arylcyclobutene and a cyclic anhydride. This reaction i~ exemplified by the following equation ~ "0 + NH2-R4-CH2NR' ~ ~NH-R4-;H2NR7 "
o The hydrocarbylene amino-bridged N-aryl cyclobutenyl amido alkenoic acid is thereafter dehy-drated by one of the methods described hereinbefore to prepare the hydrocarbylene amino~bridged N-substi-tuted arylcyclobutenyl cyclic imide. This product corresponds to the formula 28,913C-F -40 6~5 "

~ N-~4-CH2N~7 ~ O ~

wherein R4 and R7 are as hereinbefore defined.
A hydrocarbylene-bridged N-substituted aryl-cyclobutenyl cyclic imide can be prepared by the following procedure. A carboxy-substituted or carboxyhydrocarbyl-substituted arylcyclobutene is reduced to a hydroxyhydrocarbyl-substituted arylcyclobutene by reacting the starting material with about a 3:1 molar excess of diborane in an ether or cyclic ether solvent at between 0C to 20C. This process is exemplified by the following equation HOCR8 ~ ¦ + B2H6 ~ HOCH2R8 ~ 1 wherein R8 is a direct bond or a hydrocarbylene moi-ety. The hydroxyhydrocarbyl-substituted arylcyclobu-tene is reacted with a slight excess of thionyl chlo-ride to prepare a chlorohydrocarbyl~substituted aryl-28,913C-F -41-6:~$

cyclobutene. The reactants are usually contacted neat or in a methylene chloride solvent at 2 temperature of between 0C and 50C. An example of the product corresponds to the formula Cl-CH2-R8 ~1 .

The chlorohydrocarbyl-substituted arylcyclobutene is thereafter reacted with about an equimolar amount of potassium phthalamide to prepare an N-arylcyclobutenyl-hydrocarbyl phthalamide. The reactants are generally contacted neat at temperatures of between 100C and 200C. This reaction is exemplified by the following equation ClCH2-R8~ ~= ~

________~ ~ ~ CH2-N~ ~ ~ KCl 28,913C-F -42-~oo~s wherein R8 is as hereinbefore defined. The N-aryl-cyclobutenylhydrocarbyl phthalamide is reacted with about one equivalent of hydrazine hydrate to prepare an aminohydrocarbyl-substituted benzocyclobutene. The reactants are contacted in an alkanol solvent at the reflux of the solvent. The product corresponds to .the formula NH2-CH2-~1 wherein R8 is as hereinbefore defined. The aminohy-drocarbyl-substituted benzocyclobutene is thereafter reacted with an unsaturated cyclic anhydride to prepare an N-hydrocarbylarylcyclobutenyl amido alkenoic acid under the conditions described hereinbefore. This process is exemplified b~ the following equation ~ O + N112CH2R8~ ~ NHR~

wherein R3 and R8 are as hereinbefore defined. The N-hydrocarbylarylcyclobutenyl amido alkenoic acid is then dehydrated to form a cyclic imide ring thus preparing an N-hydrocarbylarylcyclobutenyl cyclic imide. This process i~ performed using one of the two dehydration processes described hereinbefore.

28,913C-F -43-3 0 ~ ~ ~ 5 To prepare a mercaptoarylcyclobutene, an arylcyclobutene sulfonic acid and equimolar.amounts of sodium hydroxide are contacted in aqueous solution at 20C-25C to prepare sodium arylcyclobutene sulfonate.
The sodium arylcyclobutene sulfonate is dried at 100C, and thereafter contacted in neat Porm with 0.48 ~ole of phosphorous pentachloride at 170C to 180C to prepare an arylcyclobutene sulfonyl chloride. The arylcyclo-butene sulfonyl chloride is reduced with zinc, 4.9 moles, in the presence of 6.8 moles of concentrated sulfuric acid at 0C to prepare the mercaptoarylcyclobutene.
To prepare the alkylenethio-bridged N-sub-stituted arylcyclobutenyl-unsaturated cyclic imide, equimolar amounts of a mercapto arylcyclobutene, sodium hydroxide and a dihaloalkane are contacted in an alka-nol solvent at between 0C and 50C. The product is a haloalkyl-substituted arylcyclobutenyl sulfide. This reaction is exemplified by the following equation HS - ~ + NaOH + R4X2 ~X-R4-S - ~ + HX

wherein X is halogen and R4 is a divalent alkane radi-cal. Two moles of the haloalkyl-substituted arylcyclo-butenyl sulfide is contacted with 0.8 moles of potassium phthalimide and 0.4 mole of potassium carbonate. The reactants are contacted neat at a tem-perature of 190C to prepare an n-phthalimidoalkyl 28,913C-F -44-~ 3 0 ~

arylcyclobutenyl sulfide. This process is exem-plified in one preferred embodimen~ by the following equation X-R4-S - ~ + ~ N-K + K2C3 `~
o O

N-R4-S ~ ~ ~ K2C03 + KX

O
The phthalimidoalkyl arylcyclobutenyl sulfide i9 contacted with a hydrazine hydrate in a mole ratio of 1 to 1.25, respectively, in an alkanol solvent at re~lux to prepare an aminoalkyl arylcyclobutenyl sulfide. In one preferred embodiment, the product corresponds to the formula H2N-R4-S~ +

.

28,913C-F -45-The aminoalkylarylcyclobutenyl sulfide is then reacted with an unsaturated cyclic anhydride to prepare a thioalkylene-bridged N-aryl cyclobutenyl minoalkenoic acid. This is achieved under conditions described hereinbefore. Thereafter, the alkylenethio N-arylcyclobutenyl amidoalkenoic acid can be dehydrated by one of the methods described hereinbefore to prepare an alkylenethiobridged N-substituted arylcyclobutenyl cyclic imide.
To prepare arylenethio-bridged N-arylcyclo-butenyl cyclic imide, equimolar amounts of a mercapto arylcyclobutene, sodium hydroxide and a halonitro-sub-stituted aromatic compound are contacted in an alkanol solvent under reflux to prepare a nitroaryl arylcyclo-butenyl sulfide. The nitro group on the nitroarylarylcyclobutenyl sulfide is reduced by contacting one mole of such compound with about two moles of tin and about six moles of concentrated hydrochloric acid to prepare an aminoaryl arylcyclobutenyl sulfide.
Theaminoaryl arylcyclobutenyl sulfide is thereafter contacted with a an unsaturated cyclic anhydride in equimolar amounts in methylene chloride at a temperature of 0C to 25C to prepare an arylenethio-bridged N-arylcyclobutenyl amidoalkenoic acid. The arylenethio-bridged N-arylcyclobutenyl amidoalkenoic acid is dehydrated using procedures described hereinbefore to prepare an arylenethio-bridged N-arylcyclobutenyl cyclic imide.
The hydrocarbylenethio-bridged N-arylcy-clobutenyl cyclic imides can be contacted with equi-molar amounts of peracetic acid in an ethyl acetate solvent at between 0C to 20C to prepare a hydrocarbylenesulfinyl-bridged N-arylcyclobutenyl 28,913C-F -46-3 ~ S

cyclic imide. The hydrocarbylenethio-bridged N-aryl-cyclobutenyl cyclic imide can be contacted with 2 moles of peracetic acid for each mole of the bridged cyclic imide in ethyl acetate solvent at 0C to 20C to prepare a hydrocarbylenesulfonyl-bridged N-arylcyclobutenyl cyclic imide.
To prepare the various bridged N-arylcyclo-butenyl cyclic imides wherein the aryl moiety is a heterocycle, the appropriately substituted hetero-cyclic N-arylcyclobutenyl cyclic imide is reacted in the manner described herein to get the appropriately desired compound.
The compounds of this invention are unique in several respects. They have intramolecular diene and dienophile functionality. They are thermally stable for long periods at elevated temperatures, up to 100C.
They are readily polymerizable. The compounds of this invention are useful in the preparation of polyimides by polymerization of one or more of the compounds of this invention. It is believed that the polymerization takes place by a Diel~-Alder reaction wherein the unsaturation on the cyclic imide acts as a dienophile while the cyclobutene ring forms a diene which reacts wlth the dienophile to form the polymeric compositions.
The polymers of this invention are prepared by heating the compounds described hereinbefore to a tem-perature o~ 170C or greater. Preferable temperatures for polymerization are 200C or greater. In general 7 it is preferable to run the polymerization at a temperature of between 170C and 300C, with between 200C and 300C being most preferred.

28,913C-F -47-:~30~i35 Wherein the N-substituted arylcyclobutenyl cyclic imides correspond to the formula \ (R ~
, ¦ N-Y-A~,C(R2)2)2 R3 ~

wherein Ar, p~1, R2, R3, Y and a are as described here-inbefore; it is believed that the polymeric composition contains units which correspond to the formula (R2)2 (R1)a ¦ R3 \ / ~ C \
Ar~ N-Y-\C /~C'/

~
(R2)2 It is further believed that in one preferred embodiment the polymers derived from monomers of such a 28,913C-F -48-3 ~ ~ 6~ 5 formula result in the preparation of polymers which correspond generally to the ~ormula (R2)2 _y ~ N-Y - - Ar ~ C(~2)2~2 R3 n ¦ 0 c O \ (R2)2 wherein Ar, R1, R2, R3, Y and a are as described here-inbefore and c is a real number of 2 or greater, and most preferably 20 or greater.
In another preferred embodiment, the poly~
meric composition is the polymer of one or more com-pounds which corresponds to the formula Q

ll (R1)b R ¦
O
wherein R1, R2, R3, Y and b are as hereinbefore de~ined. In this embodiment, lt is believed that the 28,913C-F -49-.

r 1300~;~35 polymer prepared contains units which correspond to the formula \-Y

(R )2 wherein Rl, R2, R3 J Y and b are as hereinbefore defined.
In one preferred embodiment wherein the com-pound or compounds polymerized corresponds to said formula, it is believed that the polymer prepared corresponds to the formula ~ O
R3 R ,, d (R2)2 o : wherein Rl, R2, R3, Y and b are as hereinbefore defined, and d is a real number of 2 or greater. d is preferably 20 or greater.

28,913C-F -50-~C16~S

The novel N-substituted arylcyclobutenyl-unsaturated cyclic imide compounds of this invention are useful in the preparation of polymeric compositions. In general, these polymeric compositions are prepared by contacting these N-substituted arylcyclobutenyl-unsaturated cyclic imide compounds and heating them to the polymerization temperature of the particular monomer used. The polymerization is an addition polymerization wherein no volatiles are generated. Furthermore, no cataIyst initiator or curing agents are necessary for the polymerization to take place. It is believed that the polymerization takes place when the cyclobutene ring undergoes transformation to prepare an aryl radical with two olefinic unsaturated moieties ortho to one another wherein the olefinic unsaturated moieties thereafter undergo reaction with the unsaturated cyclic imide moieties. It is to be noted that the temperature at which polymerization is initiated is dependent upon the nature of sub~tituents on the cyclobutene ring. In general, wherein the cyclobutene ring is unsubstituted, the polymerization is initiated at 200C. Wherein the cyclobutene ring is substituted with an electron-donating substituent, the polymerization temperature is generally lowered, the higher the ability of the substituent to donate electrons, the lower the polymerization initiation temperature is.
The method of polymerization of the N-sub-stituted arylcyclobutenyl unsaturated cyclic imide monomers has a significant effect on the nature and properties of the polymeric composition prepared. In one embodiment, the N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers of this invention can 28,913C-F -51-o~s be melt polymerized. The melt polymerization of N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers allows their use in the preparation of solid parts, as coatings, in composites, as adhesives and as fibers.
In one embodiment of the melt polymerization, the monomers are heated to the temperature at which it melts, preferably this is a temperature of between 80C
and 100C, and thereafter poured or injected into a mold. Thereafter, pressure may be applied on the melted monomer in the mold. &enerally, pressures of between atmospheric and 2000 psi (13,789 kPa) are suitable. Thereafter, the monomer is heated to a temperature at which the monomers undergo polymerization. This is preferably a temperature of between 200C and 300C, more preferably between 200C
and 250C for between 10 minutes and 3 hours. Upon cooling, the polymerized composition can be removed ~rom the mold.
Polymers prepared in this manner can subse-quently be thermally treated at temperatures above 200C
to raise the modulus and lower the coefficient of expansion of such polymeric compositions.
In general, the polymers prepared by this method are insoluble in that they swell but do not dis-solve, are thermally stable at 200C, have a good modu-lus, a low water pickup and are reasonably hard.
In another embodiment, the N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers of this invention can be used to prepare coatings and films. In such embodiments, the monomers are dissolved 28,913C-F -52-0t)~i35 in a suitable solvent and coated onto the substrate of - choice, and thereafter the coated substrate is exposed to temperatures at which the monomers undergo polymeri-zation over a period of time sufficient for the polymerization to go to completion. Under preferable conditions, temperatures of above 200C for between 1 and 5 hours are used. Suitable solvents are those which volatilize away at temperatures below the polymerization temperature. Preferred solvents are cyclic and aliphatic ethers, lower alkanols, amides, and chlorinated hydrocarbon solvents. It is preferable to saturate the solvent with the monomer, a 20 to 30 weight percenk concentration of monomer in the solvent is preferred.
The N-substituted arylcyclobutenyl-unsatu-rated cyclic imide monomers may be combined with the powder-form or fibrous fillers or reinforcing materials either before or after heat treatment. For example, it is possible to impregnate powder-form or fibrous fillers or reinforcing materials such as quartz sand or glass cloths, with the N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers, optionally in ~olution.
Suitable fillers and reinforcing materials are, generally, in any powder form and/or fibrous prod-ucts, for example, of the type commonly used in the production of moldings based on unsaturated polyester resins or epoxide resins. Examples o~ products such as these are, primarily, granular fillers such as quart~
powder,ground shale, asbestos powder, powdered corundum, chalk, iron powder, aluminum powder, sand, gravel and other fillers of this kind, also inorganic or organic fibers, more especially glass fibers in the 28,913C-F -53-~ ~0~;35 , --usual textile forms of fibers, filaments ro~Jings, yarns, nonwovens, mats and cloths, etc. In this connection, amino silane-based finishes have proven to be particularly effective. It is also possible to use corresponding textile structures of organic, preferably synthetic fibers (polyamides, polyesters) or on the basis of quartz, carbon, metals, etc., as well as monocrystals (whiskers).
The end products combined with fillers or reinforcing materials may be used in particular in ves-sel and pipe construction by the winding technique, in electrical engineering, in mold construction and tool making and also in the construction of heavily stressed components, in the lightweight construction of vehicles in aeronautical and astronautical engineering.
In another embodiment, the N-substituted aryl-cyclobutenyl-unsaturated cyclic imide monomers can be used as adhesives. In such embodiment, one of the sub-strates to be joined is contacted with some form of themonomers, for example, the monomer in a powdered form.
Thereafter, the second substrate to be adhesivated is contacted with the substrate previously contacted with the monomer where the monomer was contacted with the first substrate. Thereafter, pressure of at least 1 psi is applied and the monomers and substrates are raised to a temperature at which the monomer undergoes polymerization.
In one embodiment, the N-substituted aryl-cyclobutenyl-unsaturated cyclic imide monomers can be formed into a prepolymer which thereafter can be polymerized. To form the prepolymer, the N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers are 28,913C-F -54-~L~0~63S

contacted in an inert atmosphere or under vacuum and heated to a stage at which the polymerization mixture is sufficiently viscous enough to be moldable in conventional molding equipment. In general, the monomers can be contacted at a temperature of 190C to 220C for between about 1 and 10 minutes. Thereafter, the prepolymer can be used in various techniques to prepare the polymeric compositions of this invention.
In one preferred embodiment, the prepolymer is cooled to form a powder which can be used to form compression molded articles, as an adhesive, and in many other uses. In another embodiment, a prepolymer of the N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers can be prepared by precipitation polymerization. In particular, the technique involves heating such ~onomers in a solvent to prepare a low molecular weight prepolymer that contains unreacted arylcyclobutene rings. A solvent is used which dissolves the monomer but not the prepolymer. As the prepolymer forms, it precipitates and is removed. The prepolymer can be fabricated in a hot compression mold which reacts out the remaining arylcyclobutene rings to give a thermoset polymer. The product is a fine white powder.
Preferable solvents are nonpolar solvents, such as aromatic hydrocarbons, aliphatic hydrocarbons, 28,913C-F -55-aliphatic chlorinated hydrocarbons, aromatic chlori-nated hydrocarbon solvents, biphenols, naphthalenes or polychlorinated biphenols. The polymerization can take place at temperatures generally of between 200C and 240C for period~ of between 1 and 5 hours. In general, the monomer can be dissolved up to saturation in the solvent used. A 20 to 30 percent by weight solution of the monomer in the solvent is preferred.
In another embodiment, the N-substituted arylcyclobutenyl-unsaturated cyclic imide monomers can be polymerized by solution polymerization techniques.
In this embodiment, the monomers are dissolved in dipolar aprotic solvents with boiling points above the polymerization temperature of the monomers. It is preferable that the solvents have a boiling point of above 200C and more preferable that the solvents have a boiling point of above 250C. Examples of preferred dipolar aprotic solvents include amides and sulfones.
It is necessary to add to the solution lithium salts which solubilize the monomer in the solvents, preferably between 5 and 20 weight percent based on the monomer. A preferred lithium salt is lithium chloride.
The polymerization takes place by heating the polymerization solution to a temperature at which the monomer undergoes polymerization, preferably above 200C. The polymerization time is generally between about 1 and 10 hours. The polymer can be recovered by 3 adding water to precipitate the polymer from the reaction solution and thereafter stripping off the sol-vent. The polymers prepared with this method can be used in compression moldings or to prepare coatings.
It is often desirable to process these polymers under elevated temperatures.

28,913C-F -56-?0~3S

In another embodiment, t-he monomers of this invention which undergo polymerization at a temperature which is below the melting point of the monomer can be polymerized in a solid state polymerization. In this method, the monomers are heated to a temperature at which polymerization takes place. Polymers prepared in this method can be useful in the preparation of bearings, seals and other parts by powder metallurgy techniques.
The following examples are included to illus-trate the invention, and do not limit the scope of the invention or the claims. Unless otherwise specified, all parts and percentages are by weight.
Example 1 (a) Preparation of ~thyl 2-(o-Chlorobenz~l) Cyanoacetate Into a 3-liter, three-necked flask equipped with a mechanical stirrer, reflux condenser, addition funnel and nitrogen inlet was placed a solution of 35.64 g (1.55 moles) of sodium metal in 1050 mm of absolute 2B ethanol. The solution was stirred under nitrogen and cooled to 0C in an ice bath and 763.56 g (6.75 moles) of ethyl cyanoacetate was added dropwise over a period of 15 minutes. To this white suspension was added 241.56 g (1.5 moles) of o-chlorobenzyl chloride dropwise over 1 hour. After the addition was complete, the ice bath was removed and the mixture was slowly heated under nitrogen to reflux and held there ~or 3 hours. The resulting pink-colored mixture was allowed to cool under nitrogen overnight at room temperature. About 1 liter of ethanol was distilled from the reaction mixture and 1.5 liters of water were 28,913C-F -57-0~;35 added. The organic layer was taken up in three 400-ml portions of methylene chloride, and the solutions were combined and washed once with 150 ml of water. The methylene chloride solution was dried over anhydrous 5 magnesium sulfate, ~iltered and evaporated on a rotary evaporator~ The residual liquid was distilled under reduced pressure through an insulated 12-inch (30.5 cm) Vigreux column. A forerun of ethyl cyanoacetate (boiling point 55C-60C/-0.3 mm Hg) comes over first 10 followed by pure ethyl 2-(o-chlorobenzyl) cyanoacetate.
The infrared, 'H and 13C nuclear magnetic resonance were used to establish the structure. The yield was 68 percent of product having a boiling point of 130C-135C/0.3 mm Hg.
(b) Preparation of 2-(o-Chloro-benz~,rl)C~anoacetic Acid In a 2-liter, three-necked flask equipped with 20 a mechanical stirrer, addition funnel and nitrogen inlet was placed 243 g (1.02 moles) of ethyl 2-(o-chlorobenzyl)cyanoacetate. A solution of 54.52 g (1.363 moles) of qodium hydroxide pellets and 545 ml of water was added over a period of 15 minutes while 25 stirring under nitrogen. Initially, the solution turned cloudy and then became clear. The resulting mixture was stirred for 5 hours at room temperature under nitrogen. Water (445 ml) was added and the mixture was cooled in an ice bath. Acidifying to pH 1 3 with 4 N hydrochloric acid gave a fine white precipitate that was filtered and washed with water until neutral to litmus. The product was dried in a vacuum oven at 60C overnight to yield 20 g (97 percent) 35 of white powder. This material was recrystallized from toluene to give pure white crystals of 2-(o-chloro-28,913C-F -58-o~s benzyl)cyanoacetic acid identified by infrared, 'H and 13C nuclear magnetic resonance. The yield was 94 percent of product having a melting point of 132C-(c) Preparation of 3-(0-chlorophenYl) propionitrile Into a 1-liter, three-necked flask equipped with a mechanical stirrer, reflux condenser and nitrogen inlet was placed 138.5 g (0.66 mole) of 2-(o-chlorobenzyl)cyanoacetic acid and Z20 ml of dry N,N-dimethylformamide. The mixture was stirred and slowly heated under nitrogen to reflux and held there for 6 15 hours. The resulting yellow mixture was allowed to cool under nitrogen overnight at room temperature. A
precipitate (approximately 0.5 g) that formed was filtered off and the filtrate was poured into 1 liter of water. The organic layer was taken up in three 330-ml portions of ethyl ether/hexane (1:1 ~/v), and thesolutions were combined and washed once with 150 ml of water. The ethyl ether/hexane solution was dried over anhydrous magnesium sulfate, filtared and evaporated on a rotary evaporator. The residual liquid was distilled under reduced pressure through an insulated 12-inch (30.5 cm) Vigreux column with the product being collected at 82C-85C/0.3 mm Hg as a colorless liquid identified by infrared, 'H and 13C nuclear magnetic resonance. Th~ yield was 94.7 percent.
(d) Preparation of 1-C~anobenzoc~obutene A 3-liter, three-necked flask equipped with a dry ice condenser, mechanical stirrer and Claisen adapter fitted with an ammonia gas inlet and nitrogen 28,913C-F -59-~L~30~35 inlet was rinsed with acetone, dried in an oven at 125C, and heated with an air gun while flushing with nitrogen. The apparatus was cooled in a dry ice-acetone bath and the condenser was filled with a dry ice-acetone mixture. Ammonia gas flow was initiated and 600 ml was condensed out. The ammonia inlet tube was replaced by a stopper, and 0.4 g of powdered iron (III) nitrate was added. Sodium metal, 51.52 g (2.24 moles) was added in small portions over 1 hour. After all the sodium was added, the dry ice bath was removed and cooling was left to the dry ice condenser.
Complete conversion of the sodium/ammonia solution to sodamide was indicated by a color change from deep blue to gray. Next, 92.82 g (0.56 mole) of 3-(o-chloro-phenyl)propionitrile was added over a period of 10 minutes. The last traces of the nitrile were washed into the flask with small amounts of anhydrous ethyl ether. The dark green reaction mixture was stirred vigorously for 3 hours and then was treated with 134.4 g (1.68 moles) of solid ammonium nitrate. The ammonia was allowed to evaporate overnight at room temperature. Water (420 ml) was cautiously added to the residue. The organic layer was taken up in two 224-ml portions of chloroform, and the solutions were combined and washed twice with 140 ml of aqueous 5 percent hydrochloric acid and once with 140 ml of water. The chloro~orm solution was dried over anhydrous magnesium sulfate, filtered, and evaporated on a rotary evaporator. The residual liquid was distilled under reduced pressure through an insulated 12-inch (30.5 cm) Vigreux column. The product was collected at 59C-~9C/0.2 mm Hg. The infrared, 'H and 28,913C-F -~0--6 1- ~3~0635 13C nuclear magnetic resonance were run to identify the product. The yield was 50 percent.
(e) Preparation of 5-nitro--1-c~anobenzoc~clobutene Into a 500-ml, three-necked flask equipped with an addition funnel, thermometer and nitrogen inlet was placed 14.1 g (0.17 mole) of sodium nitrate and 135 ml of concentrated sulfuric acid. The mixture was stirred under nitrogen while cooling to -5C (calcium chloride/ice) and 19.5 g (0.16 mole) of 1-cyano-benzocyclobutene was added dropwise at such a rate as to keep the reaction temperature below 2C. The reaction mixture was then stirred under nitrogen at 0C-5C for 0.5 hour, poured onto 1050 g of ice, andextracted with four 300-ml portions of methylene chloride. The methylene chloride solutions were combined, washed with four 150-ml portions of 10 percent sodium bicarbonate, once with 300 ml of water, and dried over anhydrous magnesium sulfate. The methylene chloride solution was filtered and evaporated on a rotary evaporator to give 26.9 g of residue which was recrystallized from absolute 2B ethanol to give pure 5-nitro-1-cyanobenzocyclobutene identified by infrared~ 'H and 13C nuclear magnetic resonance. The melting point is 110C-112C and the yield was 64.1 percent.
(f) Preparation of 5-Amino--1`Cyanobenzoc~clobutene Into a 1-liter, three-necked flask equipped with a gas dipersion tube, reflux condenser~ rubber septum and nitrogen inlet was placed 7 g (0.04 mole) of 5-nitro-1-cyanobenzocyclobutene and 400 ml of absolute 2B ethanol. The mixture was stirred under nitrogen and 28,913C-F -61-heat was applied to dissolve the solid. After adding 2.4 ml of glacial acetic acid and 1.6 g of 5 percent palladium on carbon, hydrogen flow was initiated and the mixture was hydrogenated at atmospheric pressure and ambient temperature. The hydrogenation was followed by thin-layer chromatography (silica gel; 70 percent toluene, 25 percent ethyl acetate, 5 percent triethylamine as eluent) and this showed the reaction was essentially complete in 1 hour. After 3 hours, the hydrogen flow was stopped and the system was purged with nitrogen for l5 minutes to remove excess hydrogen gas. The catalyst was removed by filtration using Celite and quickly quenched in water. The filtrate was evaporated to dryness on a rotary evaporator and the residue was treated with aqueous 10 percent sodium hydroxide. The aqueous solution was extracted with three lO0-ml portions of ethyl ether, and the solutions were combined and washed once with lO0 ml of water.
The ethyl ether solution was dried over anhydrous potasqium carbonate, filtered and evaporated on a rotary evaporator to give an amber-colored oil that solidified on standing. The product was pumped under vacuum overnight to remove the last traces of ethyl ether and stored under nitrogen. The infrared, 'H and 13C nuclear magnetic resonance were run. The yield was 86.4 percent.
(g) Preparation of N-[5-(1-Cyano-benzocyclobutenyl)]maleamic Acid Into a 250-ml, three-necked flask equipped with a mechanical stirrer, addition funnel, reflux con-denser, thermometer and nitrogen inlet was placed 4.9 g (0.05 mole) of freshly sublimed maleic anhydride and 50 ml of dry chloroform. The mixkure was stirred under 28,913C-F -62-63 ~00635 nitrogen while cooling to 15C in an ice bath and a solution of 7 g (0.05 mole) of 5-amino-1-cyanobenzocy-clobutene in 50 ml of dry chloroform was added dropwise at such a ~ate as to keep the reaction mixture below 20C. The reaction was maintained below 20C and stirred under nitrogen for.1 hour after addition was complete. The solid N-[5-~1-cyanobenzocyclo-butenyl)]maleamic acid was filtered off, washed with cold chloroform, then with hot ethyl acetate/2B ethanol (absolute; 1:1 v/v), and dried overnight in a vacuum oven at 60C~ The infrared, 'H and 13C nuclear magnetic resonance, and carbon, hydrogen, nitrogen analyses were run.

~nal~sis Calculated Found carbon 64.46 63.80 hydrogen 4.16 4.L~4 nitro~en 11.57 11.36 The yield was 11.32 g equal to 94.25 percent and the melting point is 190C-192C.
(h) Preparation oE N-[5~ Cyano-benzocyclobuten~l)]maleimide Into a 250-ml, three-necked flask equipped with a mechanical stirrer, reflux condenser, thermometer and nitrogen inlet was placed 11 g (0.045 mole) of N-[5- (1-cyanobenzocyclobutenyl)]maleamic acid, 2.4 g (0.03 mole) of anhydrous sodium acetate, and 45.94 g (0.765 mole) of fresh glacial acetic acid. The mixture was stirred and slowly heated under nitrogen until a clear yellow solution results (117C-118C). ~fter 5 minutes 28,913C-F -63-64 ~ ~ ~

the heat was removed and the reaction mixture was allowed to cool under nitrogen overnight at room temperature. It was then slowly poured into a vigorously stirred slurry of ice and water (120 g total), and the resulting yellow precipitate filtered, washed with water until neutral to litmus, and transferred to a 500-ml beaker containing 150 ml of aqueous saturated sodium bicarbonate. This mixture was stirred for 10 minutes, then 150 ml of chloroform was added and stirred for an additional 10 minutes. The organic layer was taken up in three 50-ml portions of chloroform, and the solutions were combined and washed once with 150 ml of water. The chloroform solution was dried over anhydrous magnesium sulfate, filtered and evaporated on a rotary evaporator to give a viscous yellow oil. The product was pumped under vacuum over-night to give a yellow solid that was purified by col-umn chromatography on silica gel using 70 percent tol-uene/30 percent ethyl acetate as the eluent. Theinfrared, 'H and 13C nuclear magnetic resonance, and carbon, hydrogen, nitrogen analyses were run.

AnalYsisCalculated Found carbon 69.60 69.30 hydrogen3.60 3.70 nitrogen12.50 12.34 The yield was 5.7 g equal to 56.5 percent. The melting point is 55C-60C.

28,913C-F -64-1~0(~63S

Example 2 In a one-liter, one-necked, flask dispersed with nitrogen was placed 10 g (0.413 mole) of maleamic acid, 8.57 g (.0840 mole) of acetic anhydride, 0.2314 g (0.0013 mole) of nickel (II) acetate, 429 ml of acetone and 8.6 ml (6.24 g) of triethylamine. This solution was stirred under nitrogen ~or 64 hours. Stirring was stopped and the solution was poured into 300 ml of water saturated with sodium carbonate. Chloroform (150 ml) was added to extract the organic layer. The sodium carbonate came out of solution, collecting in the bottom of the separatory funnel. Extra water was added to the contents in the funnel to redissolve the sodium carbonate. The organic layer was then extracted and two 150-ml chloroform extractions were performed. The three chloroform extractions were combined and washed with 300 ml of water, dried over magnesium sulfate, filtered and rotovaped. ~ yellowish-brown oil was obtained and dried under vacuum for 16 hours to remove remaining chloroform. Using a column packed with silica gel and a solvent of 70 percent toluene, 30 percent ethylacetate, the product was chromatographed.
The combined ~amples containing the product (found by TLC) were rotovaped and pumped under vacuum for 16 hours. Yield was 8.97 g oY product.
Example 3 - Preparation of Poly-N-[5-(1-cyano-benzocyclobutenyl)]maleimide Into a 25-ml, two-necked flask equipped with a reflux condenser, nitrogen inlet and magnetic stir bar was placed 0~5 g (2.2 mmole) of N-[5-(1-cyanobenzocyclo-butenyl)]maleimide and 15 ml of mesitylene. The mi~ture was purged with nitrogen and heated with stirring.
Initially, all of the maleimide derivative dissolved to 28,913C-F -65--66- ~ 635 give a clear yellow solution. Upon reaching reflux, the soluti~n became cloudy and a beige powder precipitated. After 2 hours o~ reflux, the reaction was cooled and the precipitated polymer was filtered off and washed free of residual mesitylene with chloroform and dried. The yield was quantitative.
Example 4 Into a 25-ml, one-necked, round-bottomed flask equipped with a nitrogen inlet was placed 0.1 g (0.446 mmole) of N-[5~ cyanobenzocyclobutenyl)]maleimide.
The flask was purged with nitrogen and immersed in an oil bath. The bath temperature was raised to 200C over 1 hour. After heating at 200C for 20 minutes, the melted monomer solidified to a pale yellow transparent solid. The flask was cooled and the polymer removed by breaking it up with a spatula. The yield was quantitative.
- Preparation of 4-Nitrophenyl -4-Benzocyclobutenyl Ketone Into a lO0 ml roundbottom one neck flask equipped with a magnetic stirring bar, a reflux condensor and a nitrogen inlet was placed benzocyclobutene lOg(96.15 mmol) and 4-nitrobenzoyl chloride ll.9g(64.2mmol). To the flask was added Fe203 (0.65mmol, lmol %). The flask was heated to l50C under 3 a nitrogen atmosphere with vigorous stirring overnight.
The mixture was cooled to room temperature, mixed with chloroform (120 ml) and transferred to a separatory funnel. The dark brown solution was washed with 10 percent aqueous sodium bicarbonate (50 ml) twice, water (50 ml) and brine (50 ml) each once. The solution was 28,913C-F -66--67- ~3(:1~)G3S

dried over magnesium sulfate overnight and filtered through celite. The volatiles were removed on a rotovap to give a deep red-black viscous liquid. The liquid was contacted with 100 ml of n-hexane and heated to boiling. The hot n-hexane was decanted away from the undissolved brown liquid. The hexane treatment was-repeated three more times. The resultant yellow n-hexane layers were combined and slowly cooled to room temperature. An off-white solid (rosettes) precipitated out of solution. The solid was isolated by suction filtration. The filtrate was concentrated to one half of its volume and allowed to stand. The solid recovered had a weight of 4.8 grams (a 30 percent yield). NMR and IR spectra were taken of the solid and the spectra agreed with the structure of 4-nitrophenyl-4-benzocyclobutenyl ketone.
Example 6 - Preparation of 4-Aminophenyl-4-Benzocyclo-buten~l Ketone Into a 250 ml three neck round bottom flask equippe~ with a magnetic stirring bar, a reflux condensor with a nitrogen inlet and a thermometer and an equilibrating addition funnel was charged loO g t3.95 mmol) of 4-nitrophenyl-4-benzocyclobutenyl ketone, 4.46 g (19.75 mmol) of (SnCl2-2H20) and 100 ml of ethanol. Under a nitrogen atmosphere, the mixture was heated to 60C. To the mixture, in a slow dropwise manner was added sodium borohydride, 75 mg (1.975 mmol) in 20 ml of ethanol, over a period o~ 20 minutes.
After the addition, the temperature of the mixture was maintained at 60C for 30 minutes. The mixture was cooled to 10C and 80ml of water previously chilled was added. Concentrated sodium hydroxide was added until the pH was 7 (4 M, NaOH, 6 ml). The mixture was 28,913C-F -67-1~0063S

trans~erred to a 500 ml round-bottom flask and the ethanol was removed on a rotovap. Thereafter, 100 ml of water was added to the off-while slurry and the aqueous phase was extracted with diethyl ether four times with 100 ml aliquots. The ether extracts were dried over sodium sulfate overnight. The sodium sulfa~e was filtered from the diethyl ether extracts and the diethyl ether was removed on a rotovap. A
bright orange solid (0.87g) was obtained. The solid was recrystallized using carbon tetrachloride (200 ml) and decolorizing charcoal. The first crop of crystals was a pale yellow solid 0.54 g (61.3%). The carbon tetrachloride was concentrated to 50 ml and left standing overnight. NMR and IR indicate the product was 4-aminophenyl-4-benzocyclobutenyl ketone.
Example 7 - The Preparation of 0 "

1~--C ~ / C c`~

o Into a 100 ml round bottom flask equipped with a magnetic stirring bar and a nitrogbn inlet was placed l.Og(4.482 mmol) of 4-aminophenyl-4-benzocyclobutenyl ketone and 20 ml of acetone. To the solution was added 4.40g(4.482 mmol) of maleic anhydride in several portions over two minutes, with stirring. The solution was stirred at room temperature ~or two days. A white solid precipitated. The white solid was belleved to be 28,913C F -68-69~ 63S

o o ~ ~

The white solid and the solution described above are stirred with 4.9mg(8.955 mmol, 0.85ml) of acetic anhydride, 35 mg(0.142 mmol) of h~drated sodium acetate (four waters of hydration~ and 19 drops of triethyl amine. As the triethyl amine was added, the solution turned yellow. Stirring at room temperature was continued overnight. The reaction mixture was an orange hazy mixture (fine solid was present). The reaction mixture was poured into 80 ml of vigorously stirred aqueou~ sodium bicarbonate. An orange solid precipitated from the solution. To the solution was added 100 ml of chloroform, and the solution was transferred to a separatory funnel. The layers were separated and the aqueous phase was extracted with 100 ml of chloroform. The chloroform extracts were combined and washed with 50 ml of water, and then 50 ml of brine. The solution was dried over magnesium sulfate and the suction filtered through celite. The solvent was removed by a vacuum to give 1.20g of an orange viscous syrup. The product was recrystalized using ethanol and decolorizing charcoal. The mixture 3 was gravity filtered to give a pale yellow solution.
The solution was concentrated to one-half its volume and placed in ice. A white solid precipitated. The solution was allowed to stand overnight. The solid was isolated and dried in air for 1 hour. The weight of the product was 0.49g and has a melting point of 138-139C. Another 0.39g of product was further isolated to 28,913C-F -69-_70_ ~ S

give a total yield of 0.88g. The product was examined by IR and NMR and shows agreement with the following structure, 1 0 \~
o The DSC of the product indicated a melting point of 147C and an exotherm was observed at 260.4C. The energy of the exotherm was 347 J/g. A rescan of the DSC showed no melting point or exotherm but did exhibit a T2 at 260.4C.
Example 8 - Polymerization of 4-(N-maleimido)phenyl--4-Benzoc~clobuten~l Ketone Into a tube was placed 146 mg of 4-(N-maleimido)-phenyl-4-benzocyclobutenyl ketone and ni~rogen. The tube was placed into a Wood's Metal bath at 150C. The temperature was controlled and monitored with a heater and a thermocouple. The following sequence of times and temperatures were applied ~o the tube:

28,913C-F -70-~ -71- ~300~3S

150C 30 min.
180C 30 min.
210C 30 min.
235C 1 hour 260C 1 hour 270C 1 hour At the end of the sequence, the heating was stopped and the tube and thermocouple were removed from the heating bath. The tube was allowed to cool overnight.
Thepolymer was an amber color with small voids trapped in the matrix. The polymer was physically broken into small pieces. A TGA was run on one of the pieces, 0.05 wt % loss occured at 327.78C and 5~ weight loss at 464.39C.

3o 28,913C-F -71-

Claims (22)

1. A compound which corresponds to the formula wherein R1 is separately in each occurrence a hydrocarbyl, hydrocarbylthio, hydrocarbyloxy, electron-withdrawing or electron-donating group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, hydro-carbyl, hydxocarbyloxy or hydrocarbylthio;
Y is a direct bond or a divalent organic radial; and b is an integer of from 0 to 3, inclusive; with the proviso that at least two of R2 are hydrogen and the further proviso that the moieties R1, R2 and R3 do not interfere with polymerization of the compound.

2. The compound of Claim 1 wherein R1 is C1-20 alkyl, C1-20 alkoxy, C1-20 alkylthio, C6-20 aryl, C6-20 aryloxy, C6-20 arylthio, C7-20 alkaryl, C7-20 alkaryloxy, C7-20 alkarylthio, C7-20 aralkyl, C7-20 aralkoxy, C7-20 aralkylthio, cyano, carboxylate, hydrocarbylcarbonyloxy, nitro, halo, hydrocarbylsulfinyl.
hydrocarbylsulfonyl or amino;

R2 is hydrogen, cyano, halo, alkyl or alkoxy;
R3 is hydrogen, C20 alkyl, C1-20 alkozy, C1-20 alkyl-thio, C6-20 aryl, C6-20 alkoxy, C6-20 arylthio, C7-20 alkaryl, C7-20 alkaryloxy, C7-20 alkarylthio, C7-20 aralkyl, C7-20 aralkoxy or C7-20 aralkylthio; and b is an integer of 0, 1, 2 or 3.

3. The compound of claim 2 wherein R1 is C1-20 alkyl, halo, nitro or cyano; R2 is hydrogen, halo or cyano; and R3 is hydrogen or C1-20 alkyl.

4. The compound of claim 3 wherein R1 is C1-3 alkyl, halo, nitro or cyano; R2 is hydrogen or cyaslo; and R3 is hydrogen or C1-3 alkyl.

5. The compound of claim 4 wherein R2 is hydrogen; R3 is hydrogen; and b is 0.

6. The compound of claim 5 wherein Y is a direct bond, a hydrocarbylene, hydrocarbyleneamido, hydrocarbylenecarbonyloxy, hydrocarbyleneoxy, hydrocarbyleneamino, hydrocarbylenethio, hydro-carbylenesulfinyl or hydrocarbylenesulfonyl.

7. The compound of claim 6 wherein Y is a direct bond, alkylene, arylene, alkylene-bridged polyarylene, cycloalkylene-bridged polyarylene, alkyleneamido, aryleneamido, alkylenecar-bonyloxy, arylenecarbonyloxy, aryleneoxy, alkyleneoxy, arylene-amino, alkyleneamino, alkylenethio, arylenethio, arylenesulfinyl, alkylenesulfinyl, arylenesulfonyl or alkylenesulfonyl.

8. The compound of claim 7 wherein Y is alkylene or arylene.

9. A compound which corresponds to the formula wherein Ar is a carbocyclic aromatic radical;
R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo, or electron-donating group;
R3 is separately in each occurrence hydrogen, a hy-drocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and a is an integer of from 0 to 3;
with the proviso that the two carbon atoms of the (C(R2)2)2 moiety which are bound to Ar are bound to adjacent carbon atoms, the same aromatic ring of Ar; with the further proviso that at least two of R2 are hydrogen; and the further proviso that the moieties R1, R2 and R3 do not interfere with polymerization of the compound.

10. A monomer which corresponds to the formula wherein R1 is separately in each occurrence an electron-withdrawing or electron-donating group;
R2 is separately in each occurrence hydrogen, a cy-ano, an alkoxy, a halo, or an alkyl group;
R3 is separately in each occurrence hydrogen, hydro-carbyl, hydrocarbyloxy or hydrocarbylthio;
Y is a direct bond; and b is an integer of from 0 to 3, inclusive with the proviso that at least two of R2 are hydrogen with the further pro-viso that R1, R2 and R3 do not interfere with polymerization of the monomer.

11. The compound of claim 10 wherein R2 is separately in each occurrence hydrogen or cyano.

12. The compound of claim 10 which corresponds to the formula

13. The compound of Claim 1 which corresponds to the formula

14. A polymeric composition which comprises a polymer of one or more compounds which correspond to the formula wherein Ar is a carbocyclic aromatic radical R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydxocarbyl, hydrocarbyloxy or hydrocarbylthio groups Y is a direct bond or a divalent organic radicals and a is an integer of from 0 to 3; with the proviso that the two carbon atoms of the (C(R2)2)2 moiety which are bound to Ar are bound to adjacent carbon atoms on the same aromatic ring of Ar; with the further proviso that the moieties R1, R2 and R3 do not interfere with the polymerization of the compound.

15. The polymeric composition of claim 14 which contains a moiety corresponding to the formula wherein Ar is a carbocyclic aromatic radical;
R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydro-carbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and a is an integer of from 0 to 3; with the proviso that the C atoms of the C(R2)2 moleties which are bound to Ar are bound to adjacent carbon atoms on the same aromatic ring of Ar;
with the further provigo that the moieties R1, R2 and R3 do not interfere with the polymerization of the compound.

16. The polymeric composition of claim 15 which corres-ponds to the formula wherein Ar is a carcocyclic aromatic radical;
R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydrocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and a is an integer of from 0 to 3; and c is a real number of 2 or greater; with the proviso that the C
atoms o the C(R2)2 moieties which are bound to Ar are bound to adjacent carbon atoms on the same aromatic ring of Ar; with the further proviso that the moieties R1, R2 and R3 do not interfere with the polymerization of the compound.

17. A polymeric composition which comprises the polymer of one or more compounds which correspond to the formula wherein R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;

R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydrocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and b is an integer of from 0 to 3, inclusive; with the proviso that the moieties R1, R2 and R3 do not interfere with the polymerization of the compound.

18. The polymeric composition of claim 17 which contains a moiety which corresponds to the formula wherein R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydrocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and b is an integer of from 0 to 3, inclusive; with the proviso that the moieties R1, R2 and R3 do not interfere with the polymerization of the compound.

19. The polymeric composition of claim 18 which corresponds to the formula wherein R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydrocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical;
b is an integer of from 0 to 3, inclusive: and d is an integer of 2 or greater with the proviso that the moieties R1, R2 and R3 do not interfere with the formation of the polymer.

20. A polymeric composition which comprises the product prepared by exposing one or more compounds which correspond to the formula wherein Ar is a carbocyclic aromatic radical;
R1 is separately in each occurrence a hydrocarbyl, hydrocarbyloxy, hydrocarbylthio, an electron-donating or electron-withdrawing group;
R2 is separately in each occurrence hydrogen, cyano, halo or an electron-donating group;
R3 is separately in each occurrence hydrogen, a hydrocarbyl, hydrocarbyloxy or hydrocarbylthio group;
Y is a direct bond or a divalent organic radical; and a is an integer of from 0 to 3, inclusive; with the proviso that the two carbon atoms of the (C(R2)2)2 moiety which are bound to Ar are bound to adjacent carbon atoms on the same aromatic ring of Ar; with the further proviso that the moieties R1, R2 and R3 do not interfere with the polymerization of the compound to a temperature at which the compound undergoes polymerization.

21. The polymeric composition of claim 20 wherein the polymerization temperature is 175°C or greater.

22. The polymeric composition of claim 21 wherein the polymerization temperature is 200°C or greater.