JPS63179839A - Production of polyol - Google Patents

Abstract

PURPOSE:To readily obtain a polyol in good yield, by reacting formaldehyde in the presence of H2, etc., using a specific catalyst. CONSTITUTION:Formaldehyde such as paraformaldehyde, etc., is reacted in the presence of H2 or mixed gas of H2 and CO, as necessary previously reacted under N2 for prescribed time and then reacted after substituting the mixed gas by H2, in an inert organic solvent such as dioxane, using an imidazolium salt expressed by formula I (R1-R4 are aliphatic or aromatic group or H; X is halogen) such as 3-ether-1-methylbenzimidazolium bromide, formula II or formula III (n is 1-10) and a ruthenium compound such as dodecacarbonyltriruthenium, as necessary an organic amine such as triethanolamine, as a catalyst to provide 2-4C polyol such as ethylene glycol, glycerin, erythritol. The above-mentioned reaction is carried out at ordinary temperature -300 deg.C in H2 pressure of 1-500 atmosphere when H2 exists.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for obtaining polyols such as ethylene glycol, glycerin, and erythritol from formaldehyde using a catalyst consisting of a ruthenium compound and an imidazolium salt.

[Conventional technology]

There are no known examples of polyol production by reductive condensation reaction of formaldehyde.

In addition, a method for obtaining carbohydrates from formaldehyde involves the formose reaction (the catalyst is calcium hydroxide (Ca(OH)).
z), etc.), but the selectivity is generally low and products with a wide range of carbon numbers can be obtained (e.g. T, Mjzuno
and A, H, Weiss, Adv, Ca
rbohydr, Chem, Biochem, 2
9, 173 (1974)).

[Problem that the invention seeks to solve]

An object of the present invention is to provide a novel method for producing polyol from formaldehyde in good yield.

[Means for solving problems]

The present invention is characterized in that a catalyst system consisting of ruthenium, an imidazolium salt, and, if necessary, an organic amine is used for the synthesis reaction of polyol from formaldehyde. That is, the present invention produces polyol from formaldehyde in the presence of hydrogen or in the coexistence of a mixed gas of hydrogen and carbon monoxide using a catalyst system consisting of ruthenium and imidazolium salts and, if necessary, an organic amine. This provides a new method.

The ruthenium compounds used in the method of the present invention include halides, carboxylates, inorganic acid salts, oxides, compounds complexed with various organic ligands, and compounds complexed with various inorganic ligands. , etc., such as ruthenium iodide, ruthenium acetate, ruthenium dioxide,
Ru(acac)a+(CsHs)zRu, Ru, 3
(Co)+z, etc. can be exemplified. The proportion of the ruthenium compound used is not particularly limited.

Examples of the imidazolium salt which is another catalyst component of the present invention include those represented by the following general formula (1).

In the formula, R1, R2, R3, and R may be the same or different, and include aliphatic groups such as alkyl groups such as methyl, ethyl, and propyl, and alkoxy groups such as methoxy and ethoxy, and aromatic groups such as phenyl and benzyl. groups, and hydrogen (
arbitrarily selected from H).

Moreover, X represents a halogen atom such as I, Br, or CI.

As other preferable examples, the following two general formulas [■] and [
+1)) can be mentioned.

R1, R2 and X in the formula have the same meanings as above.

Moreover, n is an integer of 1 to 10.

R.

R2H,RZ (n) (III) In the present invention,
It is preferable to use an organic amine as another catalyst component together with the above ruthenium compound and imidazolium salt. Examples of such organic amines include alkylamines such as triethylamine, alkanolamines such as triethanolamine, cyclohexylamines such as dicyclohexylamine, N-alkylpyrrolidines such as N-methylpyrrolidine, N-methylpiperidine, etc. N-alkylpiperidines, N, N.

N', N'-tetramethylethylenediamine, etc.
,N.

N', N'-tetraalkyl-α,ω-alkanediamines, pyridines such as pyridine, alkylpyridine, 2-hydroxypyridine, 2-(β-hydroxyethyl)-pyridine, quinolines such as quinoline, isoquinoline, Anilines such as N,N-dimethylaniline, 1
,4-diazabicyclo-[2°2.2. ] Octane, 1
) 8-Diazabicyclo[5,4,O,co-7-undecene and other diazabicycloamines.

Formaldehyde compounds used in the present invention include:
Examples include rose formaldehyde, formalin aqueous solution, and trioxane.

The reaction of the present invention is usually carried out in the presence of a solvent. As the solvent, any organic solvent can be used as long as it is inert to the reaction. Specifically, ethers such as dioxane, diethylene glycol dimethyl ether, and 18-crown-6, esters such as methyl acetate, ethylene glycol diacetate, and T-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, N
- Amides such as methyl-2-pyrrolidone and N-benzylpyrrolidone, substituted ureas such as 1,3-dimethyl-2-imidazolitone, phenols such as phenol, m-cresol and resorcinol, and nitriles such as acetonitrile and benzonitrile. hydrocarbons such as hexane, cyclohexane, benzene, toluene, m-xylene,
Examples include aromatic hydrocarbons such as naphthalene and dodecylbenzene.

The catalyst of the present invention can also be used in the coexistence of water. The amount of water used is arbitrary as long as it does not phase separate from the organic solvent.

The method of the invention is carried out in the presence of hydrogen.

The hydrogen pressure at this time is 1 atm to 500 atm, preferably 10 to 200 atm. In addition, the reaction temperature is
It is carried out at room temperature to 300°C, preferably 50 to 200°C.

The method of the present invention can also use a mixed gas of carbon monoxide and hydrogen instead of hydrogen. The hydrogen/carbon monoxide ratio in this case is chosen arbitrarily.

The catalyst used in the method of the present invention can be prepared by separately adding a ruthenium compound, an imidazolium salt, and an organic amine if necessary to the reaction system; Depending on the situation, there is a method in which the organic amine is mixed in advance in a solvent and then introduced into the reaction system after preparation.

In the present invention, the reaction is usually carried out under hydrogen pressure at a predetermined temperature (1
It is also possible (two-stage method) to react once under nitrogen for a predetermined period of time, replace the gas with hydrogen, and then react at the same temperature as the one-stage method (two-stage method).

The nitrogen pressure in the reaction under nitrogen in this case is arbitrary,
The reaction temperature is room temperature to 200°C, preferably 50 to 1
The temperature is 50°C.

〔Example〕

The present invention will be explained in more detail below based on examples. Note that the yields of the following products are all based on the raw material formaldehyde.

The imidazolium salt used in each example has the following formula.

R1)a: RI=E t+ Rz=Me+ X=B
rR21d: R+=Me, Rz=Me+X=1) e:
R1=Et+Rz=H+X=BrExample 1 Dodecacarbonyl triruthenium (Ru+(co)+z)0
．． 1■-aton++ 3-ethyl-1-methylbenzimidazolium bromide (NMBl, EtBr, l
a) 3 mmol of triethylamine, 3101 of triethylamine, 25 mmol of paraformaldehyde, 75 mmol of water, and 20 mf of dioxane were introduced, and the air in the autoclave was replaced with hydrogen gas. Next, the same gas was introduced to 100 atm, and the reaction was carried out at 150° C. for 3 hours. After the reaction was completed, the autoclave was cooled to room temperature, the gas in the system was purged, the liquid reaction mixture was taken out, and after trimethylsilylation, it was quantified by gas chromatography, and the trimethylsilylated products of ethylene glycol, glycerin, and erythritol were each 17.9.16%. .1. Obtained with a yield of 5.5%.

Comparative Example 1 When the reaction was carried out in the same manner as in Example 1 except that (RLI3 (Co) + 2) was not used, only 0.9% of glyceraldehyde was obtained, and the polyol was not produced at all.

Comparative Example 2 Example 1 except that NMBL and EtBr (Ia) were not used.
When the reaction was carried out in the same manner as above, no C2 to C4 polyol was detected.

Example 2 When the reaction was carried out in the same manner as in Example 1 except that triethylamine was not used, ethylene glycol and glycerin were each 6. 3.3% sail was obtained.

Example 3 When the reaction was carried out in the same manner as in Example 1 except that water was not used, ethylene glycol, glycerin, and erythritol were obtained in an amount of 10.2.4.8.1.2%, respectively.

Example 4 The same catalyst solution as in Example 1 was reacted in advance at 60°C for 1 hour under 100 atmospheres of nitrogen, then the nitrogen was purged and 100 atmospheres of hydrogen was filled instead, followed by a reaction at 150°C for 3 hours. , ethylene glycol, glycerin, and erythritol each have 21. A sail of 18.6° and 3.2% was obtained.

Examples 5 to 8 By changing the type of imidazolium salt (1b in the above formula)
~1e), the results of an experiment conducted in the same manner as in Example 1 are shown in Table 1. EG, GLY, and Er1th represent ethylene glycol, glycerin, and erythritol, respectively.

Table 1 Onium salt products (%) Examples
EG GLY Er1th5 ↓
b 16.2 10.7
2.66 Rice bowl 15.0
13.3 3.87 1d
15.4 14.8 3.5
8 1dan 7.8 12.0
-9-? Yu 5.5
3.1 1.010 3
4.0 2.5 1.2
Comparative Example 3 ↓ --- 4i --- 5Ca (OH) 2-m- Comparative Examples 3 to 5 Instead of imidazolium salt, 1-ethyl-4-dimethylaminopyridinium bromide, 1-ethylquinolinium pro- Table 1 shows the results using My 1 shadow and calcium hydroxide. No product 02-C polyol was observed.

Examples 1) to 15 As other amines instead of triethylamine, triethanolamine, 134-diazabicyclo[2,2,
Table 2 shows the results of the reaction carried out in the same manner as in Example 1 except that 2,]octane, isoquinoline, 2-(β-hydroxyethyl)pyridine, and N,N-dimethylaniline were used.

Table 2 Examples Amine Product (%) EG G
LY Er1th GLAll N(C2H4
,OI+)3 23.9 13.8 3.212
DABCO9,05,92,21,213 Isokihan 19.3 Ll, 9 1.9
14 2-(β-hydroquinethyl)-pyridine(-) 22.2 9.6
1.215 N,N-dimethylaniline 5.1 3.0 - 14.6 Examples 16-18 N-methyl-2-pyrrolidone (NMP), acetonitrile (CHsCN) and dimethylformamide (DMF) instead of dioxane as solvents Table 3 shows the results obtained in the same manner as in Example 3 except for using .

Table 3 Example Solvent Product (%) EG GLY Er1th GLA
16 NMP 9.3 17.2 2.2
-17 CH,CN 4.6 4.2
1.0 -18 DMF 7.3 12
．． 6 9.4 2.0 Example 19.20 The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was different. The results are shown in Table 4. Table 4 Example Temperature Product (%) EG
GLY Er1th19 120℃ 1)
．． ．． 2 B, 1 2.120 160℃ 1
9.6 16.1 4.1 Example 21 1:1 mixed gas of carbon monoxide and hydrogen instead of hydrogen 1
Using 00 atm, Rub (GO) + z 0.1 mg-a
tom.

NMBL, EtBr 0.1 mmol, Et3N
0.1 mmo1. Using 2 mmol of paraformaldehyde, 7.5 mmof of water, and 5 ml of tetrahydrofuran as a solvent, the reaction was carried out at 150°C for 3 hours in the same manner as in Example 1. As a yield for 2 mmol of paraformaldehyde, 41% of ethylene glycol and 14% of glycerin were obtained. %was gotten.

Example 22 Ruthenium chloride (RuC) instead of Ru+(Co)+z
13) When the reaction was carried out in the same manner as in Example 1 except that 0 and 1 mg-atoWl were used, ethylene glycol, glycerin, and erythritol were reacted at 13.12.
Obtained with a yield of 1.4.2%.

〔Effect of the invention〕

According to the method of the present invention, polyols, particularly C2-C4 polyols, can be obtained in higher yield than in conventional formose reactions.

Claims (5)

[Claims] (1) A method for producing polyol from formaldehyde in the coexistence of hydrogen or a mixed gas of hydrogen and carbon monoxide using a catalyst consisting of a ruthenium compound and an imidazolium salt. (2) The method for producing a polyol according to claim 1, characterized in that an organic amine is used in combination with a ruthenium compound and an imidazolium salt as a catalyst. (3) The manufacturing method according to claim 1 or 2, wherein the ruthenium compound is dodecacarbonyltriruthenium. (4) Imidazolium salt has the formula [I] ▲ There are mathematical formulas, chemical formulas, tables, etc. , or hydrogen and X represents a halogen atom. (5) The manufacturing method according to claim 2, wherein the organic amine is triethanolamine.