JPH0320283A - Acetylation of metal cation - Google Patents

Abstract

PURPOSE: To complex a specific metal cation such as Li at a low cost by using a specific silacrown ether.

CONSTITUTION: A metal cation selected from the group consisting of Li, Na, K, Ba, Fe, Cu and Cd is complexed with a silacrown ether represented by formula. I [n is 5-10; R¹ and R² are each (unsaturated)alkyl, alkoxy, aryl, H or a group which actively assists in the complexing of a metal cation; and R³ is H or lower alkyl] (e.g. dimethylsila-14-crown-5 of formula II, etc.). As preferable groups actively assisting in the complexing of a metal cation, there can be mentioned aminoalkyl, cyanoalkyl and ethyleneoxy group.

COPYRIGHT: (C)1991,JPO

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a class of compounds known as "crown ethers" which are similar in structure and complexing properties but differ in the R substitution of 10, H, 14 with silicon groups. .

C. p. Since 1967, when David Dersen discovered crown ethers, literally thousands of applications have been developed for them to complex metal ions, solvate inorganic and organic salts in polar and non-corrosive solvents, and promote anion exchange. ability was discovered. Most of this research is based on R. Izatt and J. (Syn- by 'hristianien
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has been pirated.

There have been two problems that have hindered their widespread use, particularly in industrial processes. That is, existing synthetic methods are extremely expensive and generally have high levels of toxicity. These factors, combined with the difficulty of separating crown ethers by methods outside of production, have prevented their widespread use. One example is the acylation step in penicillin synthesis. Although cyclic polyethyleneoxysilane has been reported so far, its ring structure has fewer members than silacrown. The inner diameter of the ring structure is clearly smaller than that of lithium ions (RJieble and C. Burkh
ard's J. Am. Chem. Soc. 6
9, 2689 (1947)). Since the TI structure is extremely small, these compounds cannot form complexes with cations. The silica crown ether used in the method of the present invention has the general formula R'R" S i (OCHR" CH*) -
0 (1) [In the above formula, n is an integer from 5 to 10, and R1 and R2 are selected from the group consisting of hydrogen, alkyl, unsaturated alkyl, alkoxy, aryl, aminoalkyl, cyanoalkyl, and ethyleneoxy group. and R3 is hydrogen or lower alkyl. However, when R3 is hydrogen, at least one of R' and R2 is an aminoalkyl, cyanoalkyl or ethyleneoxy group. Thus, R3
is hydrogen and R1 and R2 are both organic groups selected from the group consisting of hydrogen, alkyl, unsaturated alkyl, alkoxy and aryl, are encompassed by the above formula. The silacrown used in the method of the present invention has the general formula HO (c}It CH
R30). H [in the above formula, n is an integer from 5 to 10, and R3 is hydrogen or lower alkyl]. Y is selected from the group consisting of alkoxy, acyloxy, amino and chloro, and Rl and R3
is alkyl, unsaturated alkyl, alkoxy, aryl,
selected from the group consisting of hydrogen and groups that actively assist in the complexation of metal cations; however, when R3 is hydrogen, at least one of R1 and R2 actively assists in the complexation of metal cations; It is produced by reacting with a silane containing a auxiliary group. The silacrowns of the present invention can be used to catalyze anion substitution reactions and complex various metal cations. Immobilized silacrownes formed by the reaction of silicon-containing materials and silacrowne ethers can be used to catalyze liquid/liquid phase transfer.

Silacrownes exhibit complexing properties that are strikingly similar to crown ethers. A specific example is dimethylsila-14-crown-5.

The name indicates the substituents on the silicon, the number of ring members and the number of oxygens. Although the number of ring members in silacrown is one less, the silicon-oxygen bond is long, so 0-CH2-CH2
0-Si-0 units with a bond length of 7596 -0 units result. A single addition of bond length is 15-crown-5
Compared to the above, there is an overall reduction in the circumference of the giant fracture by 4.5 mm.

Hereinafter, when the *verbal word is difficult to use in the name of silacrown, 'dimethyl 1' will be abbreviated. Thus, dimethylsila-14-crown-5 is converted to scilla-14-crown-5.
It can be abbreviated as.

Is Shira Crown generally appropriate? It is a colorless and odorless liquid with a viscosity of They have the ability to form stable k-molecule complexes with alkali salts or alkaline salts in solution and to behave as phase transfer catalysts in the solid state. Solvation of the metal ions leaves the anions unoccupied, thus allowing them to act as potential bases and nucleophiles. This is exemplified in a number of ways including nitrile, acetic acid, nitrite, fluoride and iodide ion substitution. Oxidation with permanganate and chromate is also promoted.

Certain silacrowns have the ability to react with silicon-containing materials to form immobilized silacrowns.

Immobilized silica crowns exhibit the same reaction catalytic ability as their unbound counterparts. These are particularly useful in liquid/liquid phase transfer reactions.

Silacrowns are easily produced by transesterification of alkoxysilanes and polyalkylene glycols.

R' R2S i (OE t )2 + HO(CH
2 CHR' O )nH-! ! -! ! +R' R2S
i(OCHR"CH, ) nO +2EtOH reaction conditions must be chosen to promote cyclization rather than polymerization. The reaction is performed using methylsulfonic acid, toluenesulfonic acid, sodium titanate and The transesterification catalysts can be catalyzed by a variety of transesterification catalysts, including a variety of other materials. Titanates are generally preferred. Each reactant is combined and from the reaction mixture about 8 g to 95% is gradually distilled.

If the silica crown to be prepared contains moieties that do not have great thermal stability, such as vinyl groups, it is advantageous to add a high boiling point solvent such as toluene.

Silica crown is removed from the reaction mixture by distillation,
This shifts the equilibrium from the polymer to Silakulakun. It is likely that in the presence of the esterification catalyst there is some molecular transfer from the polymer to silica crown during the distillation process, which causes this preferential removal of volatile silica crown from the reaction mixture. Direct reaction of chloroamino and acyloxysilanes with polyalkylene glycols can also lead to the desired products, but the yields are quite low. The silacrowne ethers used in the method of the present invention have the general formula chil, and these can be used to vary their solubility. Alkoxy, vinyl and aminoalkyl groups can be used for attachment to the substrate. Within the scope of the present invention, all R groups which are compatible with the above synthetic methods and which do not alter the crown structure are accepted [where n is 5
is an integer between ~lO, R1 and R2 are selected from the group consisting of alkyl, unsaturated alkyl, alkoxy, 7-aryl, hydrogen and groups that actively assist in the complexation of metal cations, and R3 is hydrogen and lower selected from the group consisting of alkyl]. It will be appreciated that specific examples of R groups include methyl, ethyl, benzyl, phenyl, cyclohexyl and phenene.

The value of n is limited by the possibility of recovering the silica crown product by distillation or not.
At n values greater than 0, it is impossible to separate the silica crown from the reaction mixture.

A preferred value of n is 4-7.

The following Examples 1-4 illustrate the synthesis of silacrowns.

@j1 Vinyl methyl silar 1-4-. ．． ．． Knee;-7-Kai-do. In a 250D one-neck flask equipped with a magnetic stirrer and heating mantle, add 0.5 moles (93a7) of vinylmethyldiethoxysilane, Q. 5 moles (86 at) of tetraethylene glycol and a5d of tetrabutyl titanate were charged. With a cold finger distillation head in place, the mixture was stirred at 50-60°C for 16 hours. The pot temperature was raised to 85-IQO<0>C and approximately 5 og of ethanol was removed. The mixture was then distilled under reduced pressure.

The fraction with 4A at 129-131°C was collected on CLsm. About 629 Vinyl Methyl Silah 14-Crown-5
was abbreviated. This compound was identified by infrared absorption and organic mass spectroscopy. As expected, the compound exhibited molecular ions, but at 247 (M-CH3) and at 235 (M-CH<
82) was shown.

Negative Subvinyl Methyl Silar 17-Crown-6 Under the same conditions described above, 57.4111 vinyl methyljethoxysilane, 4, & 6 II pentaethylene glycol, 0.2 d tetratitanate were added to a 250 flask. Charged with isoglobil and 25xt toluene. Approximately 2 aat of ethanol was removed at atmospheric pressure. The product snout fraction was collected at 169-172°C in an α3 tank. Shuryu is 56
It was 9.

The analysis was performed as described above.

Example 5 Under the conditions described in Example 1, 14B. A mixture of polyethylene glycol 50G,i9 having an average molecular weight of 1i500 was mixed with 5jj of dimethyldimethoxysilane. 25
0 g of dimethylsila-17-crown-6 (boiling point 169-170°C in a.s.) and 45.9 g of dimethylsila-20-crown-7 (boiling point 240 in α2■)
~244°C) was obtained.

Example 4 Methoxymethylsilah 17-crown-6 Under the same conditions as in Example 2, methoxymethylsilah 17-crown-6 (
A boiling point of 170-173°C was obtained for five fins.

Silacrowne ethers can be described as cyclic diesters of silicon atoms and polyethylene glycols, but substitutions for either the silicon atoms or the ethyleneoxy groups, or both, can significantly modify these basic structures. be able to.

Regular substitution of alkyl groups for carbon atoms of ethyleneoxy groups was found to significantly enhance the external non-polar properties of silica crown grain. This ordered substitution is achieved by substituting other polyalkylene glycols for polyethylene glycol in the transesterification reaction. In a preferred embodiment, a methyl group is substituted on the carbon atom of the ethylene oxy group by simply substituting polypropylene glycol for polyethylene glycol in the transesterification reaction.

Modified silica crowns of this type can also be easily prepared from commercially available polyalkylene glycols by transesterification with silanes according to the following reaction.

Reaction conditions must be designed to promote loam formation rather than polymerization. The reaction can be mediated by a variety of transesterification catalysts including methylsulfonic acid, toluenesulfonic acid, sodium, titanate, and various other materials known in the literature. Titanium#! Salts are generally preferred. Each reactant is combined and about 80 to 95
The alcohol by-product (where Y is alkoxy) is slowly distilled from the reaction mixture. If the silica crown to be prepared contains moieties that do not have significant thermal stability, such as vinyl groups, it is advantageous to add a high boiling point solvent such as toluene.

The modified silacrown is removed from the reaction mixture by distillation, thus changing the equilibrium from polymer to silacurawn. In the presence of a transesterification catalyst, some molecular transfer from the polymer to silica crown occurs during the distillation process;
This is believed to result in this preferential removal of volatile silica crowns from the reaction mixture.

Since the Y group is preferably an alkoxy such as ethoxy or methoxy, the alcohol by-product can be readily removed. Direct reaction of chloroamino or acyloxysilanes with polyalkylene glycols can also yield the desired products, but the yields are much lower.

Variable Silacura un produced according to the above reaction [In the above formula, R1 and R2 are organic groups or hydrogen, R3 is lower alkyl, preferably methyl, and n is 3 to
There are 10 integers].

Specific examples of the R group are methyl, ethyl, penzyl, fluorine, cyclohexyl, and phenethyl, and these can be used to change the solubility.

Alkoxy, vinyl and aminoalkyl groups can be used for attachment to the substrate. It is clear that within the scope of the present invention all R groups are acceptable which are compatible with the synthetic method described above and which do not alter the crown structure.

The value of n is limited by the possibility of recovering the silica crown product by distillation during the synthesis. 10
At n values larger than , it is impossible to separate the silica crown from the reaction mixture.

The preferred value of n is 3-7.

Another significant modification that can be made to silica crown ethers is the substitution of groups that actively assist in the complexation of various metal cations to the silicon atom. That is, at least one of the R1 and R2 substituents in the above formula can be substituted with a group such as an aminoalkyl, cyanoalkyl or ethyleneoxy group. Preferred examples of each of these groups are, respectively! 11 -CH2CH, CH2NHCH, CH2N}f
2N-(2-aminoethyl)-3-aminoprovir, (2)-CH2CH2CH2Cf'←3-cyanoprovir, +31 -OCH2Cl-120CH2CM20C
H2Cl{, CI-{20CH, triethylene glycol monomethyl ether or 1,4,7.10-tetraoxaundecyl. Other groups of this type will be apparent to those skilled in the art based on this specification.

This modified silica crown can be prepared by a transesterification reaction of the same type as previously described between a polyalkylene glycol and a R-listed silane, preferably an alkoxysilane. However, if an aminoalkyl group is used as the fife group for the silicon atom, a separate catalyst is generally not required. This is because the amine group catalyzes the transesterification reaction. Also,
If aminoalkyl groups are used as substituents, it is generally not possible to use chlorosilanes. This is because undesired chloroamines are formed.

That is, in general, a particular silane and the substituents thereon are
The hydrolyzable group on the silane is the final product of 5L! must be selected so that it does not react with one of the ffi substituents to be included in the product (fl c-)? K.

It will be appreciated that both R1 and R2 groups can be substituted with groups that actively assist in complexing the metal cation. Additionally, both of the modifications proposed by the present invention can be carried out on the same modified silacrown, so that the silacrown-biased ethyleneoxy group has an alkyl group and the silacrown has a complexing substituent. Even its existence will be buried.

The modified silica crown of the present invention can be illustrated in more detail by the following specific examples.

Example 5 Dimethylsilar 449-}limethyl-11-crown-
Preparation of Q.4 Into a one-neck flask equipped with a magnetic stirrer, heating mantle and distillation head, equimolar amounts of dimethyldiethoxysila/and tripropylene glycol and Q.4 were added. 5-tS tetrabutyl titanate was charged.

The mixture was stirred at 40°C overnight. 18 molar equivalents of ethanol were distilled from the mixture. The mixture was then distilled under reduced pressure to yield the title compound (boiling point 125-9°C/(L2
~(LlmHg) was produced in 69%, and this structure is shown in Structural Formula 2 below.

Preparation of (N-(2-aminoethyl)-3-aminopropyl)methylsilar 14-crown-5 Into a 1 liter flask, 1 mol of each N-(2-aminoethyl)-5 was added.
-Aminopropylmethyldimethoxysilane and tetraethylene glycol were charged. Approximately 17 moles of methanol were slowly distilled from the mixture (no titanate was used in this operation, since the amine groups mediate the transesterification). Fresh material was collected from the mixture. This fraction is 221~8℃/(L21EIIH
Distilled at g. A portion of the substance in the distillation flask is
The resin was dripped during the distillation. The recovered raw bottom material is approximately 55'
The yield of A was obtained, and the product is shown in the following structural formula 3.

Me Me? IJ6 Me The following Tables I-■ illustrate the use of silica crowns as soluble phase transfer catalysts. The general operation of the experiment is (L[l
5 moles of organic reactant were mixed with a 10 moles of inorganic reactant (neat or saturated aqueous solution), 25 d of acetonitrile and 1 d of silakuraqune under stirring for 16 hours.

Unless otherwise specified, reactions were carried out at ambient temperature.

Table I illustrates the displacement reaction of cyanide with benzyl bromide using or using silica crown promoted catalysis. Additionally, the table shows a comparison with 18-crown-6 and decamethylcyclopentasiloxane (D5). Reaction conditions and times were not optimized.

Table 1 illustrates anion activation and exchange reactions of halogens, pseudo-halogens, and organic anions. The reaction proceeds easily under mild conditions.

Kinugawa exemplifies solid/liquid phase transfer catalysis of potassium cyanide substitution reactions.

Solid / Liquid Solid / Liquid Solid / Liquid / Liquid / Liquid Liquid / Liquid Solid / Liquid Solid / Liquid Solid / Liquid Solid / Liquid Table ■ KCN KCN NaCN KCN KCN KCN KCN NaCN KCN Vinyl Methyl Schiller 17-Crown-6 Schiller 17-Crown -6 18-crown-6"D5'IF+ Schiller 14-crown-5 Schiller 14-crown-5 4 0 48 54% 4 0 excellent 100 100% 100 20 high 100% 3 2 Reaction literature in acetonitrile at room temperature Values decamethylcyclobentasiloxane Table ■ Table rr [ KCN catalyzed with Schiller 17-Crown-6 100% penzyl cyanide KOA c Penzyl acetate 100◆ KF Penzyl fluoride 5s KP (refluxed for 48 hours) Penzyl fluoride 35 in acetonitrile Reaction for 16 hours at ambient temperature using 15 moles of silica octyl bromide hexyl bromide penzyl chloride penzyl chloride allyl bromide penzyl chloride penzyl chloride benzyl bromide allyl bromide Lucilla 17-crown-6 18-Crown, s'll Schiller 17-Crown-6 Schiller 17-Crown-6 Schiller 14-Crown-5 18-Crown-61 Schiller 17-Crown-6 63% 100% 100% 0% 299'+ 25% 99 React at room temperature in acetonitrile at 74% and 80%. Literature value conversion Allyl cyanide and crotonitrile mixture immobilized phase transfer catalyst, methoxysilcrown mixed into a refluxing mixture of toluene and controlled pore glass. It is shaped by doing. Example 7 describes the procedure used to immobilize methoxymethylsilar 17-crown-6. The resulting immobilized silica crown is represented by structural formula 4.

Example 7 Immobilized controlled pore glass of methoxymethylsilar 17-crown-6 (80-120 meths S 226 people, 9
9 111279> was treated with 10-151 ml overnight to release the silanol form, washed with water and dried to remove moisture. In a one-neck flask, add 501 Ilt of a 2% solution of methoxymethylsilar 17-claus 7-6 and 1 ag.
It was filled with porous glass. Leave the mixture overnight! I let it happen.

The treated beads were washed with toluene and dried.

S-Schiller 17-crown-6 was used as a liquid/liquid phase transfer catalyst for various cyanide substitution reactions. The immobilized silacrown was added to a two-phase mixture containing the substrate and concentrated aqueous potassium cyanide dissolved in acetonitrile. The procedure for these experiments is described in Example 8, and the results are listed in Table ■.

Example 8 Potassium cyanide substitution promoted with an immobilized phase transfer catalyst 2 ff? I did J. α05 moles of organic reactant were mixed with 1 L1 mole of aqueous KCN and 2 g of silicawn treated glass. The reaction mixture was stirred by a magnetic stirrer at 600-L000 rpm. Product conversion was determined by gas chromatography.

Table ■ S-Schiller 17-Crown-6 Allyl bromide 16 Cyanohyalyl 454 Crotonitrile 55 S-Schiller 17-Crown-6 Benzyl bromide 25
Penzyl guanide 100 S-Sylar 17-crown-6 Benzyl chloride 16 Penzyl cyanide 97 S-S1 indicates an attached support specific cations that can be promoted using the modified silacrown compounds of the present invention. Ionization and anion reactions are
This is similar to the example given above for Shira Crown itself. In addition, the silicon atom-substituted compounds of the present invention are particularly useful for complexing barium, iron, steel, and cadmium as well as gold cations such as lithium, sodium, and potassium.

Example 9 To test the complexing properties of the compound of Example 6 above, 50
w1t chlorobenzene and 1I! Five beakers containing 100% of steel chloride were prepared. Ferrous steel chloride is a pale green solid that is essentially insoluble in chlorobenzene. 1 txl of dimethyl silica-14 in one beaker
-Crown-5 was added.

No changes were observed. To the second beaker, 5-ethylenediamine was added. The Daiichi Chloride steel turned pale blue, but the chlorobenzene remained transparent. In the third beaker, add 1 r of the compound of Example 2.
Added xl. Within a few seconds, the chlorobenzene turned pale blue. This color becomes increasingly blue over 50 minutes
This indicates the presence of a soluble @collar body.

Although the present invention has been specifically illustrated above, the present invention can be embodied in other specific forms without departing from its spirit or structure.

Claims (1)

[Claims] (1) A metal cation selected from the group of metals consisting of lithium, sodium, potassium, barium, iron, copper, and cadmium is formed with the structural formula R^1R^2Si(OCHR^3CH_2)_nO [in the above formula, n is An integer from 5 to 10, R^1 and R^2
is alkyl, unsaturated alkyl, alkoxy, aryl,
and R^3 is selected from the group consisting of hydrogen and lower alkyl.