JPS5978167A - Manufacture of 2-substituted imidazole - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The use of high efficiency products in the treatment of aqueous suspensions of particulate solid substances insoluble in water has become increasingly popular in recent years.

Therefore, there is a constant search in industry for new systems that can be used to facilitate the dewatering of aqueous suspensions of organic and inorganic materials in water and wastewater treatment, mineral processing, paper manufacturing, etc. .

Recently, polymer compositions based on imidacillin monomers have been
was introduced for the treatment of such suspensions. However, these imidacillin-based polymers 11m1d
azoline-based poly-meτ8)
is unable to maintain its effectiveness at commercial pH due to its hydrolytic instability. The difficulties and challenges inherent in the application of polymers made from imidacillin monomers are
The use of chemically related 2-vinylimidazole polymerization agents and as disclosed by Lawson in U.S. Pat. This has been largely overcome by the method of manufacture thereof modified by Oberberger as disclosed. Although the use of these 2-vinylimidazole polymers overcomes the femininity issues inherent in the use of imidacillin polymers,
Vinylimidazole polymers do not have the charge necessary to make these compositions highly effective for treating such suspensions. Thus, there is a need for other new monomers that can produce polymers that are effective in processing aqueous particulate suspensions.

A process for preparing 2-alkenylimidazoles from novel 2-substituted imidazole intermediates, which can optionally be quaternized to the corresponding 1,3-dialkyl-2-arykenylis dazolium salts. Both the 2-alkenylimidazole and '1,3-soalkyl-2-arykenylimidazolium salts, which provide Is recognized.

According to the present invention, (1) a Diels-Alder reaction between a conjugated tzene or a synthetic component that behaves similarly to a conjugated tzene in the Diels-Alder reaction and a tzene fill selected from the group consisting of acrolein and methacrolein;
(2) -Membrane structure: 6- 0 0 1111 R3-C-C-42 where R3 and R1 are individually selected from the group consisting of hydrogen, saturated aliphatic groups having 1 to 5 carbon atoms, and phenyl; and (3) about 2 equivalents of ammonia and characterized by the cracking of an fC2-substituted imidazole intermediate.

A1 reactant: Aldehyde cycloaddition product (ald
Ehyde cycloaddxct) is prepared by a conventional Diels-Alder reaction.

460.98 (19281, 470, 62 (19291
:Ber, 62.2081.2087 (1929)]
.

The suitable conjugated tsene for the reaction in this case is l,3-
Butatsuene: 1,3-pentatsuene; 1゜3-hexatsuene; 2-methyl-1,3-butatsuene; 2,3-methyl-1,3-butatsuene; cyclopentatsuene; 1-
Includes, but is not limited to, methylcyclopentatsuene; 2-methylcyclopentatsuene; cyclohexazene and hexachlorocyclopentatsuene.

Suitable synthetic components that act similarly to conjugated tene in the Diene-Alder reaction and are therefore useful in the preparation of aldehyde cycloadducts include, but are not limited to, acrolein, furan, and anthracene. Genophiles suitable for reaction with conjugated tzenes are limited to acrolein and methacrolein.

Diels-Alder between conjugate Tzen and Genophile
In carrying out the reaction, the reaction conditions will depend on the particular structure of the tzene used and which genophile is used. Reactions using methacrolein generally require relatively long reaction times and high pressures. However, in general, the reaction is completed within 1 to 20 hours by varying the reaction temperature within the range of 20 to 250°C, varying the reaction pressure within the range of 0.1 to 20 atm, and without the need for a catalyst. .

Because of the complexity of aldehyde cycloadditions resulting from the use of some of the pre-entangled tsenes, these aldehyde cycloadditions are referred to herein generally as: RI-
Denoted by CHO, where R1 is the non-aldehyde moiety of the aldehyde cycloadduct.

The alpha-soluponyl compound reacted with the aldehyde cycloadduct has the general structure: R3-C-C-R" -9-, where R2 and Bs have the same meanings as above. Although a preferred alpha-socal-nyl compound is glyoxal, any alpha-socal-nyl compound of the above general formula can be used.

Synthesis B2 The synthesis method involves reacting the aldehyde cycloaddition product with the alpha-isocarbonyl compound in the presence of two equivalents of ammonia. In the reaction of the aldehyde cycloadduct with the aldehyde-socargonyl compound, it is preferred to maintain the molar ratio of the aldehyde-socargonyl compound to the aldehyde cycloaddition within the range of about 0.9 to about 1=1. , it is also possible to IJP- this ratio. The molar ratio of ammonia to aldehyde cycloadduct is approximately 2.2
=1 to zO:1, with about Z (1:1 being preferred. It can also be prepared by using 1 equivalent of alkylamine instead of .

Although it is preferred that the synthesis reaction be carried out with the starting material in solution, the reaction can also be laled in a slurry or emulsodine. Solvents that are effective for such a reaction are generally those that are capable of dissolving all the reactants and not reacting with them under the reaction conditions, with water and suitable alcohols being preferred solvents. . Exothermic synthesis reactions are generally eliminated under stirring and atmospheric pressure within a temperature range of about -50 DEG to 100 DEG C., depending on the starting materials.

The synthesized 2-substituted imidazole intermediate has a -membrane structure: In the formula, 1? ', R2 and R3 have the same meaning as above.

・C, Cracking: By cracking the 2-substituted imidazole intermediate according to the present invention, tsene and 2-alkenylimidazole are increased as shown in the following formula: In the formula, Br, Bt and Rs are as defined above. have the same meaning and are hydrogen or methyl.

The cracking process itself uses contact or non-contact heat! In the process of decomposition, the 2-substituted imidazole intermediate is
The temperature is maintained at a temperature in the range of 0 to 800°C, preferably about 300 to 600°C, and the precise temperature depends on the structure of the intermediate, especially the one originally used in the preparation of the intermediate. Depends on Tsuen. The intermediate is generally placed in the heating zone along with a carrier, which is an inert gas or carbon dioxide gas used to convey the intermediate to the cracking equipment. Although catalysts have been found to be useful in some cases, and suitable catalysts in thermal cracking are classified as Lewis acids, it is generally preferred not to use catalysts. Alternatively, by subjecting the intermediate to similar conditions in the presence of a polymerization inhibiting agent,
Cracking can also be carried out batchwise in the condensed phase.

While the precise scope of the invention is indicated in the claims, the following specific examples illustrate certain aspects of the invention and more particularly illustrate the invention. It points out methods for evaluation.

However, these examples are set forth for illustrative purposes only and should not be considered as limitations on the invention except as described within the scope of this description. Parts and percentages are by weight unless otherwise specified.

Example 1 A sample containing 200 parts by weight of 2-(5-nor-lune-2-yl)imidazole is placed in a heated inlet chamber.

The sample is slowly sublimated into an open tube over several hours at a temperature of 445° C. and a pressure of 2.0 Torr. After passing through the heating zone, a total of 115 parts by weight of 2-vinylimidazole (97%) and 75 parts by weight of cyclopentatsuene (92%) are recovered.

Example 2 An apparatus is constructed consisting of a vertically mounted 24 inch long tube furnace containing a 1 inch diameter glass tube filled with ceramic beads in the lower 12 inches. This furnace was heated to 500°C, and a solution of 20 parts of 2=(5-nor is lune-2-yl) imidazole in the heavy phase in 80 parts of methyl alcohol was added while passing ♀ into the system.
It is fed to the upper end of the reaction tube at a rate of 3 centimeters per minute. The vapor exiting the reactor is condensed and the alcohol and cyclopentazene are removed by distillation to obtain 2-vinylimidazole in a quantitative yield.

Example 3 A mixture of 2-(methyl-5-norbornen-2-yl)imidazole prepared from a mixture of methylcyclopentazene, acrolein, 7-dioxal and ammonia was melted and prepared as described in Example 2 without solvent. Steam is passed through the system at the same time as it is fed into the cracking device. An aqueous solution of 2-vinylimidazole with methylcyclopentazene is obtained from one end of the apparatus.

Example 4 The container was kept at 600°C and 2-(3-cyclohexene-
The procedure of Example 2 is followed in detail in 1 except that the solution of 1-yl)imidazole is fed to the reactor. The material exiting the reactor is found to contain 2-vinylimidazole and 1,3-butanoene.

Example 5 2-(2-methyl-
When following procedure 111M of Example 2 using 5-norpol-2-yl)imidazole, 2-ia flovenylimidazole and cyclopentazene are produced.

Example 6 2-(Hicyclo[2
,2,2]Following the procedure of Example 2 using oct-5-en-2-yl)imidazole,! lid, 2-vinylimidazole and 1,3-cyclohexene were produced.

Examples 7 to 11 Following the procedure of Example 2 down to the details, 2-2 in Table 1
When a substituted imidazole is cracked, 2-alkenylimidazole and tsene are produced in the first H.

-17- Table 1 △ Example 2-substituted imidazole -111--
−→□ Cracking J

Claims (1)

[Claims] 1. Cracking a 2-substituted imidazole intermediate to produce a 2-
An alkenylimidazole and a diene are obtained, and the disubstituted imidazole intermediate is formed between (1) a conjugated diene or a synthetic component that acts similarly to a conjugated diene in a Hadyl-Sulder reaction and a dienophile selected from the group consisting of chlorolein and methacrolein; about 1M amount of aldehyde cycloadduct derived from the Diels-Alder reaction of
HO1 where R' is the non-aldehyde moiety of the aldehyde cycloaddition; (2)-
Membrane Structure 1-0 R3-C-C-R2, where R2 and R3 are individually selected from the group consisting of hydrogen, a saturated aliphatic group having 1 to 5 carbon atoms, and phenyl. equivalents of an alpha-so carbonyl compound; and (3) about 2 equivalents of ammonia, wherein the cracking involves passing the disubstituted imidazole intermediate into a heating zone having a temperature within the range of 100 to 800°C. A method for producing 2-alkenylimidazoles, which is achieved by the method, and the tsene produced at the time is the tsene conveniently used in the Diel-Ruder reaction. 2. The method according to claim 1, wherein the temperature of the heating zone is within the range of 300 to 600°C. The 12-substituted imidazole intermediate is derived from the reaction where the tzene is either cyclopentatsuene or methylcyclopentatsuene, the tzeneyl is acrolein, and the alpha-socarponyl compound is glyoxal. The method described in Section 1. 4. The method of claim 1, wherein the 2-substituted intermediate is 2-(5-nor is lune-2-yl)imidazole. The 52-substituted intermediate is 2-(methyl-5-norbornene-
2-yl)imidazole isomers. 6. The method according to claim 1, wherein the 2-alkenylimidazole produced is 2-vinylimidazole. 7. The method according to claim 1, wherein the 2-alkenylimidazole produced is 2-ingropenylimidazole.