Primary diamines, employed in stoichiometric excess, react with a spirodilactam precursor selected from 4-oxoheptandioic acid compounds or 1,6-dioxaspiro[4.4]nonane-2,7-diones, to produce 1,6-diaza[4.4]spirodilactams having an amino-containing substituent on each spiro ring nitrogen atom. The spirodilactams are useful in the production of thermoplastic polyamides by reaction with diacids and as curing agents for epoxy resins in the production of thermoset resins.

FIELD OF THE INVENTION 
This invention relates to a novel class of amino substituted 
spirodilactams. More particularly, it relates to novel 1,6-diaza[4.4] 
spirodilactams having an amino-containing substituents on each spiro ring 
nitrogen atom. 
BACKGROUND OF THE INVENTION 
The reaction of diamino compounds with dibasic acids or equivalent 
compounds is well known in the art. In general, the typical product from 
such a reaction is a polymer, often a thermoplastic polymer. A commercial 
example is the production Nylon 66, illustratively produced by reaction of 
adipic acid (hexanedioc acid) and hexamethylenediamine. Reaction of 
aromatic dicarboxylic acids and diamines is shown by Nakama et al., U.S. 
Pat. No. 4,595,745, and Caldwell et al., U.S. Pat. No. 3,408,334. An 
arylalkenyl dicarboxylic acid and a diamine react according to the process 
of Conciatori, U.S. Pat. No. 3,637,602. The use of a dicarboxylic acid of 
additional functionality, i.e., 4-oxoheptanedioic acid (4-oxopimelic acid) 
is shown by Ferstandig, U.S. Pat. No. 2,987,502., but the reaction was 
with a glycol and the product was a polyester. 
A class of compounds that functions in some ways similar to dicarboxylic 
acids is the class of 1,6-dioxa[4.4]spirodilactones. The simplest member 
of the series, 1,6-dioxaspiro[4.4]nonane-2,7-dione, is known and has been 
prepared, among several procedures, by the process of Pariza et al., 
Synthetic Communications, Vol. 13(3), pp. 243-254 (1983). These 
spirodilactones have demonstrated utility as an epoxy curing agent to 
produce cured compositions which do not shrink during the curing process. 
It is likely that this reaction, as well as other reactions of such 
spirodilactones, produce a ring-opened product. See, for example, the 
above Pariza et al. article and Cowsar, U.S. Pat. No. 4,064,086. A 
reaction of the spirodilactones, or of 4-oxoheptanedioic acid compounds, 
which results in a cyclic product is shown by copending U.S. Pat. 
applications Ser. No. 172,000, filed March 23, 1988 now abandoned, Ser. 
No. 172,052, filed March 23, 1988 now abandoned and Ser. No. 245,618 filed 
Sept. 16, 1988. These applications disclose the reaction of the acidic 
materials with an aminophenol wherein the hydroxyl and amino groups are 
not located on adjacent carbon atoms. Reaction of these acidic compounds 
with a stoichiometric or excess amount of a primary diamine wherein the 
two amino groups are not on adjacent carbon atoms produces polymeric 
polyamides which incorporate spirodilactam moieties as shown by copending 
U.S. Pat. application Ser. No. 245,432, filed Sept. 16, 1988. It would be 
of advantage to provide a novel class of diamines incorporating 
spirodilactam moieties which are monomeric. 
SUMMARY OF THE INVENTION 
The present invention provides a novel class of 1,6-diaza [4.4] 
spirodilactams having an amino-containing substituent on each spiro ring 
nitrogen atom. More particularly, the invention relates to reaction of a 
spirodilactam precursor selected from 4-oxoheptanedioic acid compounds or 
1,6-dioxa [4.4] spirodilactones with a diamine compound in a controlled 
reaction mixture ratio to produce a monomeric 1,6-diaza [4.4] 
spirodilactam having an amino-containing substituent on each spiro ring 
nitrogen atom. 
DESCRIPTION OF THE INVENTION 
The spirodilactam diamine compound is produced by reaction of an 
appropriate primary diamine compound, i.e., an organic compound having two 
primary amino groups (--NH.sub.2 groups) with a spirodilactam precursor. 
In one modification of the invention, the spirodilactam precursor is a 
ketodicarboxylic acid compound of up to 30 carbon atoms having two carbon 
atoms between the keto group and each carboxy function. In other terms, 
the spirodilactam precursor of this modification is a 4-oxoheptanedioic 
acid compound. Although a variety of such ketodiacids having a variety of 
substituents in addition to the keto group and the acid functions are 
useful, the preferred 4-oxoheptanedioic acid compounds are those compounds 
of up to 30 carbon atoms inclusive which are represented by the formula 
##STR1## 
wherein A independently is hydroxy, alkoxy, preferably lower alkoxy of up 
to 4 carbon atoms inclusive, or halo, preferably the middle halogens 
chloro or bromo, and Z independently is &gt;C(Z').sub.2 in which Z' 
independently is hydrogen, lower alkyl of up to 4 carbon atoms inclusive, 
preferably methyl, halo, preferably the lower halogens fluoro or chloro, 
or aryl, preferably phenyl, or Z is such that two adjacent Z groups taken 
together form a ring system Z" of from 5 to 7 ring atoms, up to two of 
which are heteroatoms selected from nitrogen, oxygen or sulfur with the 
remainder of the ring atoms being carbon atoms, there being up to 15 
carbon atoms in each Z", two of which form a bridge between the carbon 
atoms connected by the adjacent Z groups. 
In one embodiment employing the spirodilactam precursor of formula I, the 
ketodiacid is an acyclic 4-oxoheptanedioic acid compound wherein each Z is 
not a part of a fused cyclic substituent, i.e., Z is &gt;C(Z').sub.2. In one 
such embodiment, largely because of a particularly convenient method of 
producing the spirodilactam precursor, the 4-oxoheptanedioic acid compound 
has at least one hydrogen present on each carbon atom adjacent to a 
carboxy function, that is, at least one Z' present on each carbon atom 
adjacent to a carboxy function is hydrogen. Such 4-oxoheptanedioic acid 
compounds are represented by the formula 
##STR2## 
wherein A and Z' have the previously stated meanings. Such 
4-oxoheptanedioic acid compounds include 4-oxoheptanedioic acid, dimethyl 
4-oxoheptanedioate, 2,6-dimethyl-4-oxoheptanedioic acid, 
2,3,4,5-tetramethyl-4-oxoheptanedioyl chloride, di-n-propyl 
2,6-di-n-butyl4-oxoheptandioate and 
6-carboxymethyl-2,3,5,5-tetramethyl-4-oxohexanoic acid. The preferred 
compounds of the above formula Ia are those wherein Z' is hydrogen or 
methyl, particularly hydrogen, and A is hydroxy or alkoxy, particularly 
hydroxy. 
These ketodiacids are known compounds or are produced by known methods, but 
the esters of the above formula Ia are produced by the reaction of 
formaldehyde and an ethylenically unsaturated carboxylic acid ester such 
as methyl acrylate, ethyl methacrylate, butyl acrylate or methyl 
crotonate. The reaction is conducted in the presence of a catalyst system 
which comprises a thiazolium salt and a tertiary amine and produces the 
dialkyl 4-oxoheptanedioate derivative in good yield. This process is 
described in more detail and claimed in copending U.S. Pat. application 
Ser. No. 171,999, filed March 23, 1988, now U.S. Pat. No. 4,800,231, 
incorporated herein by reference. Conversion of the esters thereby 
obtained to the acids or the acid halides is by known methods. 
In a second embodiment of the ketodiacid compound as a spirodilactam 
precursor, the 4-ketodiacid incorporates fused ring cyclic substituents 
between the keto group and each carboxy function, i.e., the adjacent Z 
groups are Z". Such diacid compounds are represented by the formula 
##STR3## 
wherein A and Z have the previously stated meanings. Illustrative of these 
cyclic ketodiacid compounds are di(2-carboxycyclohexyl) ketone, 
di(2-carboxyphenyl) ketone, di(2-carbopropoxycyclo-4-pentenyl) ketone, 
di(2-chlorocarbonylphenyl) ketone, di(2-carboxypyridyl ketone, 
2-carboxyphenyl N-methyl-3-carboxy-3-pyrryl ketone, 
di(3-carboxy-2-morpholyl ketone and di(2-carboxy-3-chlorophenyl) ketone. 
The preferred cyclic ketodiacid compounds of formula Ib are those wherein 
each Z" is a ring system of from 5 to 6 ring atoms and up to one nitrogen 
atom, particularly benzo. 
The cyclic ketodiacid compounds of formula Ib are known compounds or are 
produced by known methods, for example the method of Conover et al., U.S. 
Pat. No. 1,999,181 or by the method of Cava et al., J. Am. Chem. Soc., 77, 
6022(1955). 
In yet another modification of the ketodiacid compound as the spirodilactam 
precursor, the ketodiacid compound incorporates one cyclic moiety with the 
remainder of the Z moieties being acyclic i.e., the compounds of the 
formula 
##STR4## 
wherein A, Z', and Z" have the previously stated meanings. Such ketodiacid 
compounds of one cyclic substituent are illustrated by 
3-(2-carboxybenzoyl) propionic acid, 
3-(2-carbomethoxy-2-pyridyloyl)-2-ethylpropionic acid, ethyl 
3-(2-carbethoxybenzoyl)propionate and 3-(2-carboxy-4-methylbenzoyl)butyl 
chloride. The ketodiacids of formula Ic are known compounds or are 
produced by known methods. For example, 2-carbomethoxybenzaldehyde reacts 
with methyl acrylate according to the general teachings of copending U.S. 
Pat. application Ser. No. 171,999, now U.S. Pat. No. 4,800,231 filed March 
23, 1988, to produce 3-(2-carbomethoxybenzoyl)propionate. 
In a second modification of the invention, the spirodilactam precursor is a 
1,6-dioxaspiro[4.4]nonane-2,7-dione compound of up to 30 carbon atoms 
wherein the spiro ring system is substituted with hydrogen or other 
monovalent groups or incorporates fused ring substituents which include 
the 3- and 4- spiro ring positions and/or the 8- and 9- spiro ring 
positions of the spiro ring system. One class of such spirodilactones is 
represented by the formula 
##STR5## 
wherein Z has the previously stated meaning. In the embodiment of these 
spirodilactone spirodilactam precursors of the above formula II wherein 
each Z is &gt;C(Z').sub.2, the spirodilactone is represented by the formula 
##STR6## 
wherein Z' has the previously stated meaning. Illustrative of such 
spirodilactones are 1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,8-dimethyl-1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,4,8,9-tetramethyl-1,6-dioxaspiro [4.4]nonane-2,7-dione, 
3,3,8,8-tetramethyl-1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,3,4,4,8,8,9,9-octamethyl-1,6-diazaspiro[4.4]nonane-2,7-dione and 
3,4,8,9-tetrafluoro-1,6-diazaspiro[4.4]nonane-2,7-dione. The preferred 
spirodilactones of formula IIa are those wherein at least one Z' of each 
Z'-substituted carbon atom is hydrogen. The compounds of formula IIa are 
known compounds or are produced by known methods such as by the process of 
the above Pariza et al. article, incorporated herein by reference. 
In the embodiment of the spirodilactam precursors of formula II which 
incorporate a fused cyclic substituent as a part of each of the two rings 
of the spiro ring system, the spirodilactone are represented by the 
formula 
##STR7## 
wherein Z" has the previously stated meaning. Typical compounds of this 
formula IIb are 3,4,8,9-dibenzo-1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,4,8,9-dibenzo-1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,4,8,9-di(cyclopentano)-1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,4,8,9-di(methylbenzo)-1,6-dioxaspiro[4.4]nonane-2,7-dione and 
3,4,8,9-di(pyrido)-1,6-dioxaspiro[4.4]nonane-2,7-dione. These 
spirodilactones are known compounds or are produced by known methods such 
as, for example, the process of the above Cava et al. article or by the 
general process of Conover et al., U.S. Pat. No. 1,999,181. 
In a third embodiment of a spirodilactone as spirodilactam precursor, a 
cyclic substituent is fused to one spiro ring and the other spiro ring is 
free of fused ring substituents. Such spirodilactones are represented by 
the formula 
##STR8## 
wherein Z', and Z" have the previously stated meaning. Such 
spirodilactones are illustrated by 
3-methyl-8,9-benzo-1,6-dioxaspiro[4.4]nonane-2,7-dione, 
3,4-benzo-1,6-dioxaspiro[4.4]nonane-2,7-dione and 
3,3,4,4-tetramethyl-8,9-morpholo-1,6-dioxaspiro[4.4]nonane-2,7-dione. The 
spirodilactones of the above formula IIc are produced by known methods, 
for example, by the dehydration of the corresponding ketoacid. By way of 
illustration, 3,4-benzo-1,6-dioxaspiro[4.4]nonane-2,7-dione is produced by 
dehydration of 3-(2-carboxybenzoyl)propionic acid through application of 
heat. 
In general, the preferred spirodilactones to be employed as spirodilactam 
precursors are hydrocarbyl except for the oxygen atoms of the lactone 
moieties, particularly those spirodilactones which are free of fused ring 
substituents (formula IIa) or which have a fused ring substituent on each 
spiro ring (formula lIb). The compound 1,6-dioxaspiro[4.4]nonane-2,7-dione 
is an especially preferred member of the former class while 
3,4,8,9-dibenzo-1,6-dioxaspiro[4.4]nonane-2,7-dione is an especially 
preferred member of the latter class. 
The spirodilactam precursor is reacted according to the process of the 
invention with a primary diamine, that is, an organic compound having two 
primary amino groups, i.e., --NH.sub.2 groups, as carbon atom 
substituents. While the process of the invention will take place with a 
variety of primary diamines of varying structure, best results are 
obtained in the process of the invention if the two amino groups are not 
located on adjacent carbon atoms, that is, at least one atom, carbon or 
otherwise, separates the two carbon atoms on which the primary amino 
groups are substituted. One class of such primary diamines comprises 
primary diamines of up to 30 carbon atoms inclusive which are represented 
by the formula 
EQU H.sub.2 N--R--NH.sub.2 (III) 
where R is a divalent organic radical of up to 30 carbon atoms inclusive 
and is divalent alkylene or divalent arylene of 1 or 2 aromatic rings 
which, when two rings are present, incorporates rings which are fused or 
which are connected by a link, X, wherein X is a direct valence bond, 
alkylene of up to 8 carbon atoms inclusive, oxy, thio, sulfonyl, carbonyl, 
##STR9## 
with the proviso that the two amino groups are not located on adjacent 
carbon atoms. R is hydrocarbyl, that is, contains only atoms of carbon and 
hydrogen besides any other atoms in the link X, or is substituted 
hydrocarbyl containing additionally other atoms as inert, monovalent 
substituents on carbon atoms such as halo, preferably middle halo. 
Illustrative of alkylene-containing diamines of the above formula III are 
trimethylenediamine, tetramethylenediamine, hexamethylenediamine, 
octamethylenediamine, 1,7-diamino-4-methyloctane, 1,4-diaminocyclohexane, 
1,10-diamine-5-chlorodecane and 1,6-diamino-3,4-diethylhexane. Arylene 
diamines of the above formula III include p-phenylenediamine, 
2,4-toluenediamine, 4,4'-diaminophenyl) ether, di(4-aminophenyl)methane, 
2,2-di(3-amino-4-methylphenyl)propane, di(4-amino-2-ethylphenly)sulfone, 
di(3-amino-4-chlorophenyl)ketone, di(2-aminophenyl)sulfide, 
1,3-di(4-aminophenyloxy)benzene, 2,2-di[4-(4-aminophenyloxy)phenyl]propane 
and 4,4'-di(4-aminophenyloxy)biphenyl. The preferred primary diamines are 
those diamines of the above formula III wherein R is divalent arylene and 
is hydrocarbyl except for any additional atoms present in any X. 
Particularly preferred are the di(aminophenyl)alkanes such as 
di(4-aminophenyl)alkane. Also particularly preferred are arylene groups of 
a single aromatic ring, e.g., p-phenylenediamine. 
In the reaction mixture, the ratio of the primary diamine to the 
spirodilactam precursor is of importance. If an excess of the 
spirodilactam precursor is employed, a polymeric product such as that 
described in copending U.S. Pat. application Ser. No. 245,432 filed Sept. 
16, 1988 is likely to be obtained as the principal product. To obtain the 
monomeric product of the invention the molar ratio of primary diamine to 
spirodilactam precursor should be greater than 2:1 and preferably up to 
about 8:1. The reaction is conducted in the liquid phase in the presence 
of a reaction diluent. Suitable reaction diluents are those which are 
inert to the reactants and product under reaction conditions and which 
will dissolve at least a portion of each reactant at reaction temperature. 
Such diluents include ethers, e.g., acyclic ethers such as diethylene 
glycol dimethyl ether and tetraethylene glycol dimethyl ether as well as 
cyclic ethers such as tetrahydrofuran and dioxolane, N-alkylamides such as 
N,N-dimethylacetamide and N-methyl-2-pyrrolidone, and sulfur-containing 
diluents such as dimethyl sulfoxide and sulfolane. It is particularly 
convenient to employ as a diluent, either alone or in combination with 
other diluents. A material with which water forms an azeotrope. This 
procedure facilitates the reaction and allows the water by-product to be 
removed as a generally low-boiling azeotrope. 
The reaction of primary diamine and the spirodilactam precursor takes place 
in a suitable reactor under reaction conditions which will typically 
include a reaction temperature of from about 50.degree. C. to about 
250.degree. C. but more often from about 100.degree. C. to about 
200.degree. C. Suitable reaction pressures are sufficient to maintain the 
reaction mixture in a liquid phase, e.g., pressures from about 1 
atmosphere to about 20 atmospheres. During the reaction period, the 
contact of the reactants is maintained by conventional methods such as 
stirring or refluxing and subsequent to reaction the product is recovered 
by well-known techniques such as solvent removal or precipitation. 
The spirodilactam diamine product of the invention is a 1,6-diaza [4.4] 
spirodilactam having an amino-containing substituent on each of the spiro 
ring nitrogen atoms, which substituent is a residue of the primary diamine 
when one of the primary amino groups has participated in spirodilactam 
production. In terms of the spirodilactam precursors (formulas I and II) 
and the primary diamine reactant (formula III), the product is represented 
by the formula 
##STR10## 
wherein R and Z have the previously stated meanings. The identity and 
nomenclature of such products will be apparent from consideration of the 
formulas for the reactants and product and the description of the 
reactants. By way of illustration, however, is 
1,6-di(4-aminophenyl)-1,6-diazaspiro [4.4]nonane-2,7-dione illustratively 
produced from p-phenylenediamine and either 4-oxoheptandioic acid or 
1,6-dioxaspiro[4.4]nonane-2,7-dione, 
1,6-di(3-aminophenyl)-3,4,8,9-dibenzo-1,6-diazaspiro[4.4]nonane-2,7-dione 
illustratively produced from m-phenylenediamine and either 
di(2-carboxyphenyl)ketone or 
3,4,8,9-dibenzo-1,6-dioxaspiro4.4]nonane-2,7-dione, and 
1,6-di[4]-(4-aminophenylmethyl)phenyl]-1,6-diasaspiro[4.4]nonane-2,7-dione 
illustratively produced from di(4-aminophenyl)methane and either dimethyl 
4-oxoheptanedioate or 1,6-dioxaspiro[4.4]nonane-2,7-dione. 
The spirodilactam diamine products of the invention are difunctional amines 
having a polycyclic central portion. They are useful, for example, in the 
reaction with diacids to produce thermoplastic polyamides which, in part 
because of the cyclic structure, have relatively high melting points or 
glass transition temperatures which enable application where dimensional 
stability at elevated temperatures is desired. Alternatively, the diamines 
are useful as curing agents for epoxy resins to produce thermoset resins, 
also useful in high temperature applications.

The invention is further illustrated by the following Illustrative 
Embodiments which should not be construed as limiting the invention. 
ILLUSTRATIVE EMBODIMENT I 
A mixture of 27.03 g (0.25 mole) of p-phenylenediamine, 15.6 g (0.1 mole) 
1,6-dioxaspiro[4.4]nonane-2,7-dione, 50 ml of toluene and 250 ml of 
N-methyl-2-pyrrolidone was heated while being stirred to 
140.degree.-150.degree. C. and water present or formed was removed by 
azeotropic distillation. When water removal was complete, the temperature 
of the mixture was raised to 180.degree. C. and maintained at that 
temperature for 1 hour. The resulting mixture was cooled and poured into 
ether. The precipitated product was recovered by filtration, washed with 
ethyl acetate and dried in a vacuum oven. The product had a melting point 
of 137-148.degree. C. and the nuclear magnetic resonance spectra were 
consistent with the structure. The spirodilactams are useful in the 
production of thermoplastic polyamides by reaction with diacids and as 
curing agents for epoxy resins in the production of thermoset resins. 
ILLUSTRATIVE EMBODIMENT II 
The procedure of Illustrative Embodiment I was repeated except that 17.4 g 
(0.1 mole) of 4-oxoheptanedioic acid was used instead of the 
spirodilactone. The recovered, dried product had a melting point of 
143.degree.-146.degree. C.