JPH0469156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel imidazolium compounds and methods for synthesizing the compounds.

The novel imidazolium compound (hereinafter referred to as Q salt) obtained by the method of the present invention is a precursor for the synthesis of 2-vinyl-4,6-diamino-s-triazine (hereinafter referred to as VT). Useful as a substance.

The present inventors reacted 2-[β-{2'-methylimidazolyl-(1)'}-ethyl]-4,6-diamino-s-triazine (hereinafter abbreviated as 2MA) with benzyl chloride or allyl chloride. By letting
It has been found that the new imidazolium compound (Q salt) can be obtained in high yield, and that VT can also be obtained in high yield by reacting the Q salt with an alkali.

These matters can be explained using a reaction formula as follows.

or The starting material 2MA in the above reaction formula is a compound obtained in good yield from acrylonitrile, 2-methylimidazole and dicyandiamide by the method described in Japanese Patent Publication No. 47-36391.

The yield of the reaction to produce Q salt from 2MA is good, and the yield of the reaction to produce VT from Q salt is also good, and each reaction is easy to operate, so the method of the present invention is suitable for industrial use. It can be said that it is suitable for implementation on a large scale.

Next, the embodiment of this reaction will be described.

After heating and refluxing a base system consisting of 2MA, benzyl chloride, an appropriate amount of sodium sulfide (Na ₂ S 9aq) as a polymerization inhibitor, and an appropriate amount of solvent alcohol for about 2 hours under stirring, the thus obtained product was obtained. The production system is cooled and the crude target product (Q salt) is collected by filtration.

The molar ratio of 2MA to benzyl chloride is between 1:1 and 1:2.0, with a molar ratio of 1:1.5 being most preferred. The amount of solvent alcohol is preferably at least the same weight as 2MA.

Suitable alcohols include methanol, ethanol and isopropanol.

Although various commercially available polymerization inhibitors (eg, hydroquinone, etc.) other than sodium sulfide can be used, the use of sodium sulfide is the most economical.

Purification of the crude target product is carried out by a recrystallization method according to a conventional method. Water or alcohol is used as a resolubilizing agent.

Next, other embodiments of this reaction will be described.

After heating the base system consisting of 2MA, allyl chloride, an appropriate amount of sodium sulfide (Na ₂ S.9aq) as a polymerization inhibitor, and an appropriate amount of acetic acid at 75 to 93°C for about 4 hours with stirring, The resulting product system is cooled and the crude target product (Q salt) is collected by filtration.

The molar ratio of 2MA and allyl chloride is 1:1 to 1:
2.0, but a molar ratio of 1:1.5 is most preferred. The amount of acetic acid is preferably at least the same weight as 2MA.

The structural formula and properties of the target product thus obtained are as shown below.

Neutral colorless crystal. mp233~234℃ (W)
Easily soluble in DMSO or acetic acid. Soluble in water. Poorly soluble in methanol or ethanol.

ν ^KBr _cn-1 : 3350 (third absorption), 3140 (third absorption) 1650 (first absorption), 1525 (third absorption) 1450 (third absorption), 1420 (second absorption) 1400 (fourth absorption) ), 1330 (6th absorption) 1230 (9th absorption), 1205 (9th absorption) 1165 (7th absorption), 808 (5th absorption) 780 (8th absorption) NMR (d ₆ -DMSO): δ7. 73, s, 2H (4 and 5 protons of imidazole); 6.74, br.s, 8H (-
NH ₂ ); 4.40, m, 4H (methylene adjacent to imidazole); 2.88, m, 4H (methylene adjacent to triazine); 2.64, s, 3H (methyl group) Mass: m/e M ⁺ does not appear 219 (2MA) 82 (2-methylimidazole) 36 (HCl) Elemental analysis C% 42.29 (42.80), H% 5.86 (5.39), N% 41.97 (42.78), Cl% 8.90 (9.03) However, the values in brackets are theoretical values.

The reaction to synthesize VT from Q salt is very easy. If the Q salt is briefly heated in an aqueous solvent with an amount of alkali greater than the amount required to neutralize the chlorine ions, sparingly soluble VT will precipitate from the solution, which is filtered out.
Then, by recrystallization, the purified target product can be obtained. As the alkali, alkali hydroxide, alkali carbonate, alkali bicarbonate, etc. are most suitable.

Next, embodiments of the present invention will be described by way of examples.

Example 1 An original system consisting of 0.1 mol (21.9 g) of 2MA, 0.2 mol (25.32 g) of benzyl chloride, 0.002 mol (0.48 g) of sodium sulfide (Na ₂ S・9aq), and 24 g of ethanol was heated for about 2 hours. After heating to reflux with stirring, the resulting system was cooled to obtain the crude target product (Q salt).
0.048 mol (18.84 g, yield 96 mol % based on 2MA) was collected by filtration.

The m.p. of this material is 222-225°C.

After recrystallizing the crude target product with methanol, it was further recrystallized once more with water to obtain 0.041 mol (16.1 g,
A yield of 82 mol% relative to 2MA was obtained.

On the other hand, an aqueous potassium carbonate solution was added to the filtrate from which the crude target was collected by filtration until the overall pH reached 12, and after the precipitated crystals were collected by filtration, they were subjected to methanol reconsolidation and heated to mp209-210℃.
0.04 mol (11.98 g, 80 mol % yield based on 2MA) of crystals was obtained. The infrared spectrum of the crystal is 1,
It was consistent with 3-dibenzyl-2-methylimidazolium chloride.

Example 2 0.1 mol (21.9 g) of 2MA, sodium sulfide (Na ₂ S.
A system consisting of 0.01 mol (2.4 g) of acetic acid and 30 ml of acetic acid was heated to 100°C with stirring to completely dissolve it, and then 0.2 mol (15.3 g) of allyl chloride was added to the system at 30 ml of acetic acid.
Drop for 1 minute, then 75-93℃ for another 4 hours.
The internal temperature was maintained. The product system thus obtained was cooled, and 0.037 mol (14.5 g, yield of 74 mol % based on 2MA) of the precipitated crude target product (Q salt) was obtained. The mp of this stuff is 213-218°C. The above crude target product was dissolved in hot water, a small amount of insoluble matter was filtered off while hot, and the crystals precipitated from the filtrate were collected by filtration upon cooling, and the identified sample was 0.03 mol (12.3 g, yield of 62 mol % based on 2MA). I got it. On the other hand,
The filtrate obtained when the crude target product was filtered was subjected to atmospheric distillation to obtain 3 g of unreacted allyl chloride and 13 g of allyl alcohol acetate. Furthermore, the distillation residue was made basic with potassium carbonate and distilled under reduced pressure (20 mmHg) to recover about 2 g of 2-methylimidazole.

Reference example A system consisting of 0.1 mol (39.25 g) of Q salt, 100 ml of water, and 0.2 mol (27.6 g) of potassium carbonate was briefly heated under reflux, the resulting system was cooled, and the precipitated crystals were collected by filtration. Then, after washing the crystals with hot methanol, the crystals were recrystallized once with water to obtain 0.084 mol (11.51 g, 84% yield based on Q salt) of VT.

The hot methanol washing solution was dried and the residue was reconsolidated with water to obtain 0.078 mol of 2MA (17.1 g, yield based on Q salt).
78 mol%).

Claims (1)

[Claims] 1. Structural formula 1,3-di-[β-{4',6'-diamino-s-triazinyl-(2)'}-ethyl]-2-methylimidazolium chloride. 2 Structural formula 2-[β-{2′-methylimidazolyl-
(1)′}-Ethyl]-4,6-diamino-s-triazine and benzyl chloride are reacted in the presence of sodium sulfide to produce 1,3-di-[β-{4′,
A method for synthesizing 6'-diamino-s-triazinyl-(2)'}-ethyl]-2-methylimidazolium chloride. 3 Structural formula 2-[β-{2′-methylimidazolyl-
(1)′}-Ethyl]-4,6-diamino-s-triazine, allyl chloride, sodium sulfide, and acetic acid.
A method for synthesizing di-[β-{4,6-diamino-s-triazinyl-(2)′}-ethyl]-2-methylimidazolium chloride.