Method for handling (2-alkyl) (acryloyl) isocyanate, method for stabilizing (2-alkyl) (acryloyl) isocyanate, method for producing (2-alkyl) (acryloyl) isocyanate, heterocyclic compound, and method for producing heterocyclic compound

A method for producing a (2-alkyl)acryloyl isocyanate of the formula I EQU CH.sub.2 .dbd.C(R.sup.1)--C(O)--NCO (I) wherein R.sup.1 is defined herein, from the dissociation of a compound of formula III ##STR1## wherein R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are defined herein and wherein the dissociation of the compound of formula III produces the compound of formula I and a compound of formula II EQU (R.sup.3) (R.sup.4)C.dbd.N--R.sup.2 (II) wherein R.sup.3, R.sup.4 and R.sup.2 are defined herein.

FIELD OF THE INVENTION 
The present invention relates to a method for handling an acyl isocyanate 
compound, a method for stabilizing the acyl isocyanate compound, a method 
for producing the acyl isocyanate compound, a heterocyclic compound, and a 
method for producing the heterocyclic compound. Particularly, the present 
invention relates to a method for handling a (2-alkyl)acryloyl isocyanate, 
a method for stabilizing the (2-alkyl)acryloyl isocyanate, a method for 
producing the (2-alkyl)acryloyl isocyanate, a novel heterocyclic compound, 
and a method for producing the novel heterocyclic compound. 
BACKGROUND OF THE INVENTION 
(2-Alkyl)acryloyl isocyanates represented by acryloyl isocyanate, 
methacryloyl isocyanate, and the like contain a polymerizable 
carbon-carbon unsaturated group and an isocyanate group in the same 
molecule. Since these functional groups react with different mechanisms to 
participate in various reactions, utilization of (2-alkyl)acryloyl 
isocyanates in the fields of synthesis chemistry, polymer chemistry, etc., 
is expected. 
For example, European Patent Application No. 0177122-A (corresponding to 
JP-A-60-231644) discloses use of a (2-alkyl)acryloyl isocyanate for 
synthesizing a novel compound represented by formula (4): 
##STR2## 
(wherein R's may be the same or different and each represents a lower 
alkyl group). (The term "JP-A" as used herein means an "unexamined 
published Japanese patent application.") 
Further, European Patent Application No. 0177122-A (corresponding to 
JP-A-61-17554) discloses the use of a (2-alkyl)acryloyl isocyanate for 
synthesizing a novel compound represented by formula (5): 
##STR3## 
(wherein R represents a lower alkyl group and Z represents an organic 
group having a tertiary amino group). 
Both of the novel compounds respectively represented by formulae (4) and 
(5) have been proved to be useful in the fields of paints and plastics. It 
is therefore increasingly expected that other useful novel compounds will 
be synthesized from (2-alkyl)acryloyl isocyanates. 
Although (2-alkyl)acryloyl isocyanates, which are expected to be 
effectively utilized, are stable compounds which are liquid at ordinary 
temperature, it is difficult to handle them. Specifically, the 
(2-alkyl)acryloyl isocyanates are extremely reactive with moisture in air 
and are thus readily denatured. In addition, the isocyanates have a strong 
irritating odor and tend to impair working conditions. Because of these, 
the (2-alkyl)acryloyl isocyanates should be carefully handled using a 
syringe, etc. 
SUMMARY OF THE INVENTION 
An object of the present invention is to facilitate the handling of a 
(2-alkyl)acryloyl isocyanate. 
Another object of the present invention is to easily stabilize the 
(2-alkyl)acryloyl isocyanate. 
Still another object of the present invention is to produce the 
(2-alkyl)acryloyl isocyanate in a simplified manner. 
A further object of the present invention is to provide a novel 
heterocyclic compound. 
Still a further object of the present invention is to provide a method for 
producing the novel heterocyclic compound. 
The handling method and stabilization method according to the present 
invention are methods for handling and stabilizing a (2-alkyl)acryloyl 
isocyanate represented by formula (1): 
##STR4## 
(wherein R.sup.1 represents a hydrogen atom or a lower alkyl group). 
This handling method may comprise the steps of reacting an azomethine 
compound represented by formula (2) with the (2-alkyl)acryloyl isocyanate 
to obtain a reaction product and dissolving crystals of this reaction 
product into a solvent to regenerate the (2-alkyl)acryloyl isocyanate; 
##STR5## 
(wherein R.sup.2 represents an alkyl group, a cycloalkyl group, an aralkyl 
group, an alkenyl group, or an alkynyl group, and R.sup.3 and R.sup.4 each 
represents a hydrogen atom or a group which does not cause tautomerism 
with C.dbd.N in the formula, provided that at least one of R.sup.3 and 
R.sup.4 is not a hydrogen atom). 
The method for handling a (2-alkyl )acryloyl isocyanate, according to the 
present invention, may also comprise the steps of reacting an azomethine 
compound represented by formula (2) with the (2-alkyl ) acryloyl 
isocyanate to obtain a compound represented by formula (3) and dissolving 
this compound into a solvent to regenerate the (2-alkyl ) acryloyl 
isocyanate; 
##STR6## 
(wherein R.sup.5, R.sup.6, R.sup.7, and R.sup.8 each is the same as 
R.sup.1, R.sup.2, R.sup.3, and R.sup.4, respectively, defined in formulae 
(1) and (2)). 
The method for stabilizing a (2-alkyl)acryloyl isocyanate, according to the 
present invention, comprises the steps of preparing an azomethine compound 
represented by formula (2) and reacting this azomethine compound with the 
(2-alkyl)acryloyl isocyanate to form a heterocyclic compound represented 
by formula (3). 
The method of the present invention for producing a (2-alkyl)acryloyl 
isocyanate comprises the steps of preparing a heterocyclic compound 
represented by formula (3) and dissolving this heterocyclic compound into 
a solvent. 
The novel compound of the present invention is a heterocyclic compound 
represented by formula (3). 
The method of the present invention for producing a heterocyclic compound 
is a method for producing the novel heterocyclic compound represented by 
formula (3). This method comprises the steps of preparing a 
(2-alkyl)acryloyl isocyanate represented by formula (1), preparing an 
azomethine compound represented by formula (2), and reacting the 
(2-alkyl)acryloyl isocyanate with the azomethine compound.

DETAILED DESCRIPTION OF THE INVENTION 
Handling Method 
In the handling method of the present invention, a (2-alkyl)acryloyl 
isocyanate represented by formula (1) is handled. 
##STR7## 
In formula (1), R.sup.1 represents hydrogen or a lower alkyl group. The 
lower alkyl group herein means an alkyl group having 1 to 5 carbon atoms. 
This alkyl group may be branched. Examples of the alkyl group include 
methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, and 
pentyl. 
Especially preferred in the present invention are methacryloyl isocyanate, 
represented by formula (1) wherein R.sup.1 is methyl, and acryloyl 
isocyanate, represented by formula (1) wherein R.sup.1 is a hydrogen atom. 
(First Step) 
In this method for handling the (2-alkyl)acryloyl isocyanate, an azomethine 
compound represented by formula (2) is first reacted with the (2-alkyl) 
acryloyl isocyanate to stabilize the isocyanate. 
##STR8## 
In formula (2), R.sup.2 represents an alkyl group, a cycloalkyl group, an 
aralkyl group, an alkenyl group, or an alkynyl group. 
The alkyl group preferably has 1 to 18 carbon atoms. The alkyl group may be 
linear or branched, and may be a primary, secondary, or tertiary alkyl 
group. Examples of the primary alkyl group include methyl, ethyl, propyl, 
butyl, isobutyl, hexyl, 3-ethylhexyl, octyl, and octadecyl. Examples of 
the secondary alkyl group include isopropyl, 1,5-dimethylhexyl, and 
1-ethylpropyl. Examples of the tertiary alkyl group include t-butyl and 
t-octyl. 
The cycloalkyl group preferably has not more than 18 carbon atoms 
(particularly 3 to 18 carbon atoms). Examples of such cycloalkyl groups 
include cyclohexyl, cyclopentyl, adamantyl, and cyclodecyl. 
The aralkyl group preferably has not more than 18 carbon atoms 
(particularly 3 to 18 carbon atoms). Examples of such aralkyl groups 
include benzyl, phenylbenzyl, and 4-phenylbenzyl. 
The alkenyl group preferably has not more than 18 carbon atoms 
(particularly 3 to 18 carbon atoms). This alkenyl group may be linear or 
branched, and may contain a cyclic structure. Examples of such alkenyl 
groups include allyl, oleyl, and 2-cyclohexenyl. 
The alkynyl group preferably has not more than 6 carbon atoms (particularly 
3 to 6 carbon atoms), and may be linear or branched. Examples of such 
alkynyl groups include propargyl. 
The alkyl group described above may be partly substituted with a halogen or 
an alkoxy group. The cycloalkyl, aralkyl, alkenyl, and alkynyl groups 
described above each may be partly substituted with at least one of an 
alkyl group, halogen, nitro group, cyano group, alkoxy group, and silyl 
group. 
In formula (2), R.sup.3 and R.sup.4 each represents a group which does not 
cause tautomerism with C.dbd.N in formula (2). Examples of such group 
include a hydrogen atom and a group in which a carbon atom located in the 
.alpha.-position to carbon atoms constituting a heterocyclic ring does not 
have a hydrogen atom. 
Examples of the group in which the .alpha.-position carbon does not have a 
hydrogen atom include aryl groups, e.g., phenyl, p-methylphenyl, 
p-chlorophenyl, o-ethoxyphenyl, p-nitrophenyl, biphenyl, m-phenoxyphenyl, 
2-naphthyl, and 9-anthranyl; heterocyclic groups, e.g., pyridyl, furyl, 
and 3-thienyl; alkaryl groups, e.g., tolyl and xylyl; and tertiary alkyl 
groups, e.g., t-butyl and 2,2-dimethylpentenyl. These groups each may be 
partly substituted with at least one of alkyl group, halogen, nitro group, 
cyano group, alkoxy group, silyl group, and phenyl group. R.sup.3 and 
R.sup.4 may be the same or different, provided that at least one of 
R.sup.3 and R.sup.4 is not a hydrogen atom. 
Specific examples of the azomethine compound represented by such formula 
(2) include p-methylbenzylidene-benzylamine, 
p-methoxybenzylidenebenzylamine, p-chloro-benzylidenebenzylamine, 
p-phenylbenzylidenebenzylamine, naphthylmethylidenebenzylamine, 
furylmethylidene-n-butyl-amine, vinylidenecyclohexylamine, 
benzylidenecyclohexylamine, benzylidene-n-butylamine, 
benzylideneoctadecylamine, benzylidenebenzylamine, benzylideneallylamine, 
benzylidene-t-butylamine, .alpha.-phenyl-p-methylbenzylidenebenzylamine, 
.alpha.-phenylbenzylidenecyclohexylamine, 
.alpha.-naphthylbenzylidene-benzylamine, 
.alpha.-p-chlorophenylbenzylidenebenzylamine, 
.alpha.-t-butylbenzylidenebenzylamine, and 
2,2-dimethylpropylidene-benzylamine. 
In reacting the (2-alkyl)acryloyl isocyanate with the azomethine compound 
described above, the azomethine compound is used in an amount of 
preferably from 0.5 to 5 equivalents, particularly preferably from 1.0 to 
1.5 equivalents, per 1 equivalent of the (2-alkyl)acryloyl isocyanate. The 
reaction temperature is desirably regulated in the range of from 
-20.degree. to 50.degree. C. If the reaction temperature is lower than 
-20.degree. C., the reaction proceeds with difficulty, so that the 
stabilization treatment is required for a longer time. On the other hand, 
if the reaction is carried out at a temperature of higher than 50.degree. 
C., there is a fear that the reaction product may be decomposed to make 
the attainment of the object impossible. The reaction temperature is 
particularly preferably at room temperature (e.g., from 10.degree. to 
25.degree. C.). 
This reaction (step) may be performed without or using a solvent. 
In the case of using a solvent, the solvent is not particularly limited in 
kind as long as it does not adversely influence the reaction of the 
(2-alkyl)acryloyl isocyanate with the azomethine compound. Solvents having 
active hydrogen, such as, e.g., alcohols, cannot be used because such 
solvents are highly reactive with the (2-alkyl)acryloyl isocyanate. It is 
necessary that any usable solvent should be sufficiently dehydrated before 
use, since the (2-alkyl)acryloyl isocyanate is highly reactive with water. 
Examples of solvents usable in the above reaction include aliphatic 
hydrocarbons, e.g., hexane and heptane; aromatic hydrocarbons, e.g., 
benzene and toluene; ethers, e.g., diethyl ether, dibutyl ether, and 
dioxane; halogenated hydrocarbons, e.g., methylene chloride, ethylene 
chloride, dichloroethane, dichlorobenzene, chloroform, and carbon 
tetrachloride; and ketones, e.g., methyl ethyl ketone, methyl isobutyl 
ketone, and acetone. 
The reaction described above is completed earlier by precipitating the 
resulting heterocyclic compound as crystals (described later). The 
precipitation of the heterocyclic compound as crystals is accelerated by 
conducting the reaction using a nonpolar solvent, in particular, a 
nonpolar solvent having a dielectric constant of less than 5. Examples of 
the solvent having a dielectric constant of less than 5 include aliphatic 
hydrocarbons, e.g., hexane and heptane; aromatic hydrocarbons, e.g., 
benzene and toluene; and ethers., e.g., diethyl ether, dibutyl ether, and 
dioxane. 
The reaction described above yields crystals. These crystals consist of a 
heterocyclic compound represented by formula (3). 
##STR9## 
In this heterocyclic compound, R.sup.5, R.sup.6, R.sup.7, and R.sup.8 each 
is the same as R.sup.1, R.sup.2, R.sup.3, and R.sup.4, respectively, 
defined in formulae (1) and (2) described above. 
The (2-alkyl)acryloyl isocyanate is stabilized by being converted into such 
heterocyclic compound. This heterocyclic compound can be easily isolated 
by filtration. In filtration, the reaction system is preferably cooled to 
-20.degree. C. or lower; this cooling brings about an increased recovery. 
(Second Step) 
The subsequent step in the handling method of the present invention is to 
regenerate the (2-alkyl)acryloyl isocyanate from the heterocyclic 
compound. In this step, crystals of the heterocyclic compound are 
dissolved into a solvent in which the crystals are soluble. Usable 
solvents include halogenated hydrocarbons (e.g., chloroform); esters 
(e.g., ethyl acetate and dimethyl carbonate); ketones (e.g., methyl 
isobutyl ketone); and amides (e.g., N-methyl-pyrrolidone). Especially 
preferred are polar solvents having a dielectric constant of 5 or higher. 
Upon dissolution of crystals of the heterocyclic compound into a solvent, 
the heterocyclic compound dissociates into the (2-alkyl)acryloyl 
isocyanate and the azomethine compound both used as starting compounds. 
This dissolution is desirably conducted at room temperature or at a higher 
temperature of 100.degree. C. or less. If the temperature for dissolution 
is lower than room temperature, the heterocyclic compound is dissociated 
with difficulty, resulting in a decreased degree of regeneration of the 
(2-alkyl)acryloyl isocyanate. On the other hand, if the temperature for 
dissolution is too high, there is a fear that the (2-alkyl)acryloyl 
isocyanate regenerated through dissociation may be subjected to a side 
reaction. The particularly preferred dissolution temperature is from 
40.degree. to 60.degree. C. 
The (2-alkyl)acryloyl isocyanate thus-obtained by dissolving the 
heterocyclic compound into a solvent can be used as it is for a subsequent 
synthesis reaction. For example, by using a solvent containing an active 
hydrogen compound (e.g., an alcohol), the (2-alkyl)acryloyl isocyanate can 
be recovered as an adduct of the active hydrogen compound. It is also 
possible to isolate the (2-alkyl)-acryloyl isocyanate by a separation 
technique (e.g., distillation), before the isocyanate is used in a 
synthesis reaction. Consequently, according to the handling method 
comprising the first and second steps described above, the 
(2-alkyl)acryloyl isocyanate can be handled easily as compared with the 
case in which the isocyanate is directly used as it is. 
Stabilization Method 
The first step of the handling method described above can be utilized as a 
method for stabilizing the (2-alkyl)acryloyl isocyanate. Namely, a 
(2-alkyl)acryloyl isocyanate is stabilized by being converted into a 
stable heterocyclic compound. This stabilization method for a 
(2-alkyl)acryloyl isocyanate can be easily accomplished by merely mixing 
the (2-alkyl)acryloyl isocyanate with the azomethine compound described 
above. The (2-alkyl)acryloyl isocyanate thus stabilized can be regenerated 
by merely dissolving the heterocyclic compound formed by the stabilization 
into a solvent. This method is therefore effective in storing a 
(2-alkyl)acryloyl isocyanate over a prolonged time period or in 
transporting the same. 
Method for Producing (2-Alkyl)acryloyl Isocyanate 
The second step of the handling method described above can be utilized as a 
method for producing a (2-alkyl)acryloyl isocyanate. Namely, a 
(2-alkyl)acryloyl isocyanate can be extremely easily produced by merely 
dissolving the heterocyclic compound described above into a solvent. 
The heterocyclic compound for use in this production method may be the 
heterocyclic compound produced in the first step of the handling method 
described above, or may be a heterocyclic compound synthesized by another 
chemical method. 
Heterocyclic Compound and Method for Production Thereof 
The heterocyclic compound obtained in the first step of the handling method 
described above is a novel heterocyclic compound provided first according 
to the present invention. This compound is a solid having a melting point 
and is thermally stable. It is stable also to moisture. Furthermore, the 
novel heterocyclic compound has a low vapor pressure and is less 
irritating. 
Since the heterocyclic compound has a polymerizable double bond, it is 
expected to be used as a material for producing a polymer for use in 
paints, adhesives, plastics, etc. Furthermore, since the carbon-carbon 
double bond contained in this heterocyclic compound is highly reactive, 
the heterocyclic compound is also expected to be used as an intermediate 
for the synthesis of fine chemical products, e.g., medicines and 
agricultural chemicals (i.e., pesticides). 
The first step of the handling method described above can be utilized as it 
is as the method of the present invention for synthesizing the 
heterocyclic compound. 
The present invention will be explained below in more detail by reference 
to the following Examples, but the invention should not be construed as 
being limited thereto. 
EXAMPLE 1 
The azomethine compound (1.7 g: 9.0 mmol) shown in Table 1 was added in a 
nitrogen stream to a solution of methacryloyl isocyanate (1.0 g: 9.0 
mmol), represented by the following structural formula (6), in dry benzene 
(10 ml). The obtained mixture was stirred at 20.degree. C. 
##STR10## 
A white precipitate was generated after 20 minutes, but stirring was 
further continued thereafter. After the reaction was performed over 180 
minutes in total, the white precipitate yielded was separated by 
filtration to obtain colorless needles. The filtrate was concentrated, and 
the resulting solid was washed with diethyl ether to further obtain 
colorless needles. The yield of all these colorless needles obtained was 
44%. 
The crystals obtained were measured with respect to melting point, IR 
spectrum, and NMR spectrum. The results are shown in Table 2 below. 
As is apparent from the results in Table 2, the crystals obtained were 
ascertained to be the novel compound represented by the following 
structural formula (7). 
##STR11## 
EXAMPLE 2 
Using the same methacryloyl isocyanate (1.0 g: 9.0 mmol) as in Example 1, a 
crystal was obtained in the same manner and under the same conditions as 
in Example 1, except that the azomethine compound (1.96 g: 9.0 mmol) was 
changed to those shown in Table 1. The yield of the crystal was 54%. The 
crystals obtained were measured with respect to melting point, IR 
spectrum, and NMR spectrum. The results are shown in Table 3 below. 
As is apparent from the results in Table 3, the crystals obtained were 
ascertained to be the novel compound represented by the following 
structural formula (8). 
##STR12## 
EXAMPLES 3 TO 8 
The same procedure as in Example 1 was carried out, except that the 
azomethine compound and the reaction conditions were changed as shown in 
Table 1 and Table 4, respectively. Thus, crystals of heterocyclic 
compounds were obtained. 
The structural formulae and analytical data for the heterocyclic compounds 
obtained are shown in Table 5 and Table 6, respectively. 
TABLE 1 
______________________________________ 
Azomethine compound 
##STR13## 
Example R.sup.2 R.sup.3 R.sup.4 
______________________________________ 
##STR14## 
##STR15## H 
2 
##STR16## 
##STR17## H 
3 
##STR18## 
##STR19## H 
4 
##STR20## 
##STR21## H 
5 
##STR22## 
##STR23## H 
6 CH.sub.3(CH.sub.2 ) .sub.3 
##STR24## H 
7 
##STR25## 
##STR26## H 
8 
##STR27## 
##STR28## H 
9 
##STR29## 
##STR30## H 
______________________________________ 
TABLE 2 
______________________________________ 
Melting 75.about.76.degree. C. 
point 
IR 1673 cm.sup.-1 (CO) 
1647 cm.sup.-1 (CN) 
NMR 7.4 ppm (b. s) 
5H Ar. H 
6.4 ppm (b. s) 
1H PhCH 
6.0 ppm (b. s) 
1H 
CH.sub.2 
5.5 ppm (b. s) 
1H 
4.5 ppm (b) 1H 
##STR31## 
2.0 ppm (s) 3H CH.sub.3 
1.8.about. 10H cyclohexyl H 
0.8 ppm (b. m) 
______________________________________ 
TABLE 3 
______________________________________ 
Melting 
point 
IR 1673 cm.sup.-1 (CO) 
1640 cm.sup.-1 (CN) 
NMR 7.4 ppm (d) 2H 
Ar. H 
6.9 ppm (d) 2H 
6.4 ppm (b. s) 
1H PhCH 
6.0 ppm (b. s) 
1H 
CH.sub.2 
5.6 ppm (b. s) 
1H 
4.5 ppm (b. s) 
1H 
##STR32## 
3.75 ppm (s) 3H CH.sub.3 O 
1.95 ppm (s) 3H 
##STR33## 
1.8.about. 10H cyclohexyl H 
0.8 ppm (b. m) 
______________________________________ 
TABLE 4 
______________________________________ 
Methacryloyl 
Azomethine 
isocyanate compound Temperature 
Time 
Example 
g (mmol) g (mmol) Solvent 
(.degree.C.) 
(min) 
______________________________________ 
3 1.0 (9.0) 1.0 (5.1) benzene 
20 200 
4 1.0 (9.0) 1.0 (4.8) benzene 
20 75 
5 1.0 (9.0) 1.0 (4.3) benzene 
20 40 
6 1.0 (9.0) 1.0 (6.2) benzene 
20 180 
7 1.1 (10.0) 1.7 (9.0) diethyl 
20 60 
ether 
8 1.1 (10.0) 1.7 (9.0) diethyl 
20 60 
ether 
9 1.0 (9.0) 1.0 (4.4) benzene 
20 180 
______________________________________ 
TABLE 5 
______________________________________ 
Heterocyclic compound 
##STR34## 
Example 
R.sup.5 
R.sup.6 R.sup.7 R.sup.8 
______________________________________ 
3 CH.sub.3 
##STR35## 
##STR36## H 
4 CH.sub.3 
##STR37## 
##STR38## H 
5 CH.sub.3 
##STR39## 
##STR40## H 
6 CH.sub.3 
CH.sub.3(CH.sub.2 ) .sub.3 
##STR41## H 
7 CH.sub.3 
##STR42## 
##STR43## H 
8 CH.sub.3 
##STR44## 
##STR45## H 
9 CH.sub.3 
##STR46## 
##STR47## H 
______________________________________ 
TABLE 6 
______________________________________ 
Yield Melting point 
IR 
Example (%) (.degree.C.) 
(cm.sup.-1) 
______________________________________ 
3 72 74-75 1669 (C = O) 
1634 (C = N) 
4 78 65-66 1671 (C = O) 
1636 (C = N) 
5 97 67-68 1673 (C = O) 
1634 (C = N) 
6 44 68-69 1667 (C = O) 
1640 (C = N) 
7 99 69-71 1671 (C = O) 
1634 (C = N) 
8 89 34-35 1671 (C = O) 
1636 (C = N) 
9 68 132-134 1673 (C = O) 
1640 (C = N) 
______________________________________ 
EXAMPLES 9 TO 11 
Deuterated chloroform was introduced into a sample tube for measurement of 
NMR spectrum. Thereto was added the heterocyclic compound represented by 
the following structural formula (9). Measurement of NMR spectrum was then 
carried out under the conditions shown in Table 7 to determine the degree 
of regeneration of methacryloyl isocyanate. The results obtained are shown 
in Table 7. 
##STR48## 
TABLE 7 
______________________________________ 
Conditions Degree of 
Example 
Solvent Temperature (.degree.C.) 
Time regeneration (%) 
______________________________________ 
9 deuterated 
28 instant 
33 
chloroform 
10 deuterated 
48 instant 
50 
chloroform 
11 deuterated 
60 instant 
75 
chloroform 
______________________________________ 
EXAMPLES 12 TO 14 
The degree of regeneration of methacryloyl isocyanate was determined in the 
same manner as in Examples 9 to 11, except that the heterocyclic compound 
was changed to that represented by the following structural formula (10). 
The results obtained are shown in Table 8. 
##STR49## 
TABLE 8 
______________________________________ 
Conditions Degree of 
Example 
Solvent Temperature (.degree.C.) 
Time regeneration (%) 
______________________________________ 
12 deuterated 
28 instant 
33 
chloroform 
13 deuterated 
45 instant 
50 
chloroform 
14 deuterated 
60 instant 
75 
chloroform 
______________________________________ 
EXAMPLES 15 TO 17 
The degree of regeneration of methacryloyl isocyanate was determined in the 
same manner as in Examples 9 to 11, except that the heterocyclic compound 
was changed to that represented by the following structural formula (11). 
The results obtained are shown in Table 9. 
##STR50## 
TABLE 9 
______________________________________ 
Conditions Degree of 
Example 
Solvent Temperature (.degree.C.) 
Time regeneration (%) 
______________________________________ 
15 deuterated 
28 instant 
44 
chloroform 
16 deuterated 
45 instant 
62 
chloroform 
17 deuterated 
60 instant 
75 
chloroform 
______________________________________ 
EXAMPLES 18 TO 20 
The degree of regeneration of methacryloyl isocyanate was determined in the 
same manner as in Examples 9 to 11, except that the heterocyclic compound 
was changed to that represented by the following structural formula (12). 
The results obtained are shown in Table 10. 
##STR51## 
TABLE 10 
______________________________________ 
Conditions Degree of 
Example 
Solvent Temperature (.degree.C.) 
Time regeneration (%) 
______________________________________ 
18 deuterated 
28 instant 
44 
chloroform 
19 deuterated 
45 instant 
56 
chloroform 
20 deuterated 
60 instant 
76 
chloroform 
______________________________________ 
According to the handling method of the present invention, a 
(2-alkyl)acryloyl isocyanate which is difficult to handle can be easily 
handled, because the (2-alkyl)-acryloyl isocyanate is first converted into 
a stable heterocyclic compound and the heterocyclic compound is then 
treated to regenerate the (2-alkyl)acryloyl isocyanate therefrom. 
According to the stabilization method of the present invention, a 
(2-alkyl)acryloyl isocyanate can be extremely easily stabilized by merely 
adding a given azomethine compound thereto. 
According to the method of the present invention for producing a 
(2-alkyl)acryloyl isocyanate, the (2-alkyl)-acryloyl isocyanate can be 
obtained extremely easily by merely dissolving the stable heterocyclic 
compound into a solvent. 
According to the present invention, a novel heterocyclic compound which is 
useful in the fields of synthesis chemistry and polymer chemistry can be 
provided. 
According to the method of the present invention for producing a novel 
heterocyclic compound, the heterocyclic compound which is useful in the 
fields of synthesis chemistry and polymer chemistry can be produced. 
While the invention has been described in detail and with reference to 
specific embodiments thereof, it will be apparent to one skilled in the 
art that various changes and modifications can be made therein without 
departing from the spirit and scope thereof.