JPH04112863A - Amino acid derivative and gelling agent - Google Patents

Abstract

NEW MATERIAL:A compound of formula I (R1 is aralkyloxycarbonyl; R2 is H, alkyl, aryloxycarbonyl; R3 is long chain alkyl; L is a single bond divalent connecting group; X is electron-attracting group; m is 1-4; n is an integer of >=1). USE:A gelling agent. Useful as a domestic waste oil treating agent, liquid fuel- solidifying agent, food-coagulating agent, etc. PREPARATION:A compound of formula II produced from an acid halide and an amino acid compound is condensed with a compound of formula III in the presence of a dehydrating agent to produce the compound of formula I.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a novel compound, an amino acid derivative, and a gelling agent.

<Prior art> Gels have existed in foods such as konnyaku and tokoroten for a long time, and in the field of photography, gelatin gels are still used as binders for emulsion layers in films etc. Since then, it has become a familiar part of our lives.

Furthermore, recently, polymer gels have been used in a wide variety of fields, such as soft contact lenses containing water and disposable diapers made from superabsorbent resins.

By the way, gels contain solvents and swell.
Most of these are hydrogels (aqueous gels) that contain water as a medium, and it is this type that is being put into practical use.

On the other hand, in recent years, the problem of sewage treatment has become increasingly important from the standpoint of environmental conservation and water resource conservation, and it is known that a large amount of water is required to treat waste oil and the like.

For this reason, waste oil treatment agents using ribogel (oil-based gel) using an organic solvent as a medium have been put into practical use for the treatment of waste oil and the like. For example, such compounds include 12-hydroxystearic acid, dibenzylidene sorbitol, N-acylamino acid amides such as N-lauroyl-glutamic acid dibutylamide, and the like.

Among such oil gelling agents, those using amino acids such as N-acylamino acid amides are listed as "
Modern Chemistry No. 1978 issue (1987) p54-5
You can refer to the description in 9 (Tokyo Kagaku Doujin Series) j.

This amino acid-based oil gelling agent is not only effective as a waste oil treatment agent, but also because it is an amino acid-based compound.
It is thought that there will be no negative impact on the ecosystem, and it is also expected to be used as a material for preventing oil spills, such as preventing the spread and recovering oil spills caused by tanker accidents. In addition, new uses such as pharmaceutical sustained release control agents and biocatalyst-immobilized gels are also considered, so it is significant to obtain a new compound that can be used as a gelling agent.

<Problems to be Solved by the Invention> An object of the present invention is to provide a novel amino acid derivative and a gelling agent.

<Means for Solving the Problems> Such objects are achieved by the following configurations of the present invention (1) and (2).

(1) An amino acid derivative represented by the following general formula (I).

General formula (I) (In the above general formula (I), R1 represents an aralkyloxycarbonyl group, R2 represents a hydrogen atom, an alkyl group, or an aryloxycarbonyl group, and R2 represents a long-chain alkyl group. L is simply Represents a bond or a divalent linking group. X represents an electron-withdrawing group. m is 1
．． 2.3 or 4, and n represents a positive integer of 1 or more. When n is 2 or more, mutual R2:! 3 and 3 may be the same or different, respectively. ) (2) A gelling agent represented by the following general formula (I).

General formula (I) (in the above formula (■), R1 represents an aralkyloxycarbonyl group, R2 represents a hydrogen atom, an alkyl group or an aryloxycarbonyl group, and R3 represents a long-chain alkyl group. L is Represents a sheep bond or a divalent linking group. X represents an electron-withdrawing group. m is l, 2.3 or 4, and n represents a positive integer of 1 or more. n is 2 or more. When, each other's R213 and L
may be the same or different. ) <Specific Configuration> Hereinafter, the specific configuration of the present invention will be described in detail.

The amino acid derivative of the present invention is represented by the following formula (I).

General Formula (1) In the above formula (I), R1 represents an aralkyloxycarbonyl group, R2 represents a hydrogen atom, an alkyl group or an aryloxycarbonyl group, and R3 represents a long-chain alkyl group. L represents a simple bond or a divalent linking group. X represents an electron-withdrawing group. m is 1.
2.3 or 4, and n represents a positive integer of 1 or more. When n is 2 or more, R2 and L may be the same or different.

Next, formula (I) will be explained in detail.

The aralkyloxycarbonyl group represented by R1 is preferably a phenyl group as an aryl group, and specific examples include benzyloxycarbonyl and phenethyloxycarbonyl.

Among them, benzyloxycarbonyl is preferred.

The alkyl group represented by R2 may be unsubstituted or may have a substituent, and the unsubstituted alkyl group is preferably a methyl group or the like. Further, the substituted alkyl group is a substituted ethyl group, a substituted butyl group, etc. In this case, the substituent preferably contains an oxygen atom or a nitrogen atom, and furthermore, it preferably contains a small number (both one or more carbonyl bonds). Those having the following are preferred. Examples of such substituents include ester groups, amide groups, and the like.

Preferred substituted alkyl groups include those represented by the following formulas (A) to (C).

Formula (A) υ (Here, Y represents an electron-withdrawing group such as a nitro group, an acyl group, etc., and k is a positive integer of 1 to 5. When k is 2 or more, Y may be the same They may be different. In particular, those in which =2 and Y is a nitro group and an acyl group are preferred, and those in which the acyl group has 12 to 18 carbon atoms are preferred.) Formula (B) -(CH2) 4NH[nee R4 (Here, R4 represents a substituted or unsubstituted alkyl group having 11 to 17 carbon atoms, and the alkyl group may be linear or branched.) Formula (C) -(CH,)4NHC-ORs (Here, R6 represents an aralkyl group, and those having a phenyl group as an aryl group are particularly preferred.) The aryloxycarbonyl group represented by R2 is represented by the following formula (D). Preferable examples include those that can be used.

Formula (D) (Here, Y and k have the same meanings as in formula (A).) -M As R2 in formula (I), hydrogen atom, formula (A
) to (D), those that are preferred are particularly preferred.

Furthermore, the long chain alkyl group represented by R3 has 5 carbon atoms.
-17, particularly preferably 11-15. Further, although this material may be linear or branched, it is preferable that the number of carbon atoms forming the main chain is at least 5 or more, particularly 11 to 15.

Examples of the divalent linking group represented by L include alkylene groups, and specific examples include +CH2+- (p=1 to 5) and substituted products thereof.

Among L, preferred are simple bonds, CH2-, -
CH2CH2-1-f-CH2) 3-CH- (wherein, R5 is a substituted amino group, etc., and examples of the substituent include ester groups such as benzyloxycarbonyl group), and the like.

Examples of the electron-withdrawing group represented by X include a nitro group and a cyano group, with a nitro group being preferred.

m is particularly preferably 1, and X is an acyl group.
Those substituted at the meta position of (-COR3) are preferred.

In particular, n is preferably 1 or 2, and n is 2
When , R2 and L are preferably different from each other.

Specific examples of the amino acid derivative represented by formula (I) will be listed below, but the invention is not limited thereto.

(I-1) The amino acid derivative represented by formula (I) is synthesized according to the following scheme.

A) (I-2) (I-3) First, an amino acid derivative having an amide bond into which R (aralkyloxycarbonyl group) has been introduced is synthesized by reacting acid halides R and Cρ with an amino acid compound. [A) Ko.

On the other hand, p-acylphenol is produced from a phenolic ester having R3 (long-chain alkyl group) using a Friedelta raft type catalyst, and then N O2- etc. are introduced to perform nitration etc. [B] ].

Then, the compound obtained in A] and the compound obtained in B) are condensed in the presence of a dehydrating agent to obtain the desired product [C)]
.

In this way, synthesis can be performed relatively easily.

Furthermore, in the above, the actual synthesis is generally performed in step C), and in such a case, the synthesis is particularly simple.

The amino acid derivative thus obtained is an amphiphilic compound having a hydrophobic long-chain alkyl group and a hydrophilic amino acid derivative group, and has a molecular weight of 500 to 1000.

Identification of this amino acid derivative can be performed by elemental analysis, NMR spectrum, and IR spectrum.

The amino acid derivative of the present invention forms a gel by heating and dissolving it in various non-aqueous solvents.

Examples of the nonaqueous solvent in this case include alcohols such as methanol, polar solvents such as ethyl acetate, and nonpolar solvents such as cyclohexane, carbon tetrachloride, hexane, and benzene.

It is thought that such a gel is formed when molecular aggregates generated by intermolecular hydrogen bonds take on a fibrous structure or the like.

This is supported by the results of NMR spectra and observations by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) (see Experimental Examples).

In addition, observation by TEM suggests that amino acid derivatives form a higher-order structure with a bilayer membrane as a constituent unit in a non-aqueous solvent, and a gel is formed based on this higher-order structure. it is conceivable that.

In this bilayer membrane, the direction of the hydrophilic part in the molecule depends on the polarity of the solvent, with the parent xylem facing outward in a highly polar solvent, and the hydrophilic part facing inward in a weakly polar solvent. .

Furthermore, when forming a gel, in the CD spectrum,
The strong circular dichroism (CD) suggests that the aggregate has some kind of anisotropic structure.

As mentioned above, the amino acid derivative of the present invention is relatively easy to synthesize and can be used in a wide variety of non-aqueous solvents for gelation, so it is expected to be used as a gelling agent. Moreover, this product also has a high ability to form a gel.

Specifically, it is a spilled oil coagulation treatment agent that can be used as an oil gelling agent to solidify spilled oil to prevent its dispersion, and the solidified product can be easily recovered, as well as household waste oil. It can be used as a waste oil treatment agent that can be solidified and disposed of as garbage. In this case, in any case,
Since it is an amino acid derivative, there is no concern about toxicity or secondary contamination.

Furthermore, it can be used not only for waste oil treatment but also for the treatment of organic solvents disposed of in factories and the like.

Furthermore, since it gels alcohol, it can be used as a gelling agent for producing isomorphic fuels.

In addition, it can also be used as a gelling agent, such as a coagulant for foods.

<Examples and Experimental Examples> The present invention will be specifically described below with reference to Examples and Experimental Examples.

Example 1 Compounds (I-1), (I-2), and (I-3) were synthesized according to the following scheme.

/l・Compound ■-3) The thus obtained compound ■■■ was subjected to elemental analysis and measurements of MR spectrum and IR spectrum.

The results are summarized below.

elemental analysis NMR spectrum (reference material TMS, ? medium D 3 O.D.) (■ 67.26 5.34 5.23 7.94 8.09 CI-2) 70,01 5.20 5.11 9.27 (■ 66, 51 66, 80 6.93 6.63 7.67 7.63 δ 5.07 [ ζ)≧, -o-co- ] From the above results In any compound δ 0.9, 1.1-1.9 (methylmethylene group) too, It can be seen that the measured value and the theoretical value match.

・Mumus (I-2) (3) IR spectrum (KBr tablet method) A 1
I-1) 1780 cm-' (C=0 ester group) 65, 14
(ζΣu-o-co-)δ 0.9, 1.1~2
．． 2 (methylmethylene group) 1540 cm-' (amide) H compound (1-21 1780 cm-' (C=0 ester group) 1540 cm
-' (amide) Mu I-3 l-3l780 ' (C=0 ester group) 65.10
((y1□-o-co-)δ 0.94.1~
2.1 (methylmethylene group) 1540 cm-' (amide) From the above results, the above synthetic compounds correspond to compounds (I-1), (I-2) and (I-3), respectively. I understand that.

Next, a gel was formed using compounds (1-1), (I-2) and (I-3), and various studies were conducted on the gel structure and the like.

This is shown below as an experimental example.

Dissolve the above compounds (1-1), (I-2), and (I-3) by heating in methanol and cyclohexane as a solvent,
After that, it was placed in a constant temperature bath to form a gel (heat dissolution method).
. The minimum concentration (C, G, C,) required for gelation was determined in the temperature range of 15 to 60°C.

Among these, for compound (I-1), methanol,
FIG. 1 shows a plot of the sol-gel transition temperature at each predetermined concentration using cyclohexane as a solvent and methanol as a solvent for compound (I-2). The upper region of the plot shows the sol state, and the lower region shows the gel state.

As is clear from FIG. 1, C, G, and C do not gel at low concentrations unless the temperature is quite low, but as the concentration increases, the transition temperature becomes constant around 40°C.

For one λD-compound (I-1), add methanol to 18
FIG. 2 shows part of the NMR spectra (reference material external reference tetramethylsilane) at 50° C. (sol) and 25° C. (gel) when used as a medium.

As shown in FIG. 2, in sol (a), the phenyl proton (Ha) located between the nitro group and the valmitoyl group of the 2-nitro-4-balmitoyl-phenoxy group has a chemical shift (δ) of 8. At 3 and 8.6 ppm, the phenyl proton (H5) adjacent to the valmitoyl group and located at the p position of the nitro group is located at 68.3 and 8.2 ppm, and the methylene proton of the benzyloxycarbonyl group is at 65
．． 1 and 5. Absorption was observed around 8 ppm of O.

The chemical shift of these signals was thought to be due to the association of protons in the parent xylem, which was influenced by the ring current of the benzene ring. The signal believed to be due to the associated molecules disappears in the spectrum of gel (b) in Figure 2 at 25°C. On the other hand, the signal likely to be due to unassociated molecules did not change. From the relationship between C, G, C and temperature and NMR spectrum, regardless of sol or gel,
It is believed that unassociated, freely behaving molecules are always present in the solvent. However, as the temperature decreases, the associated molecules will continue to associate, forming a network and forming a gel, and some of the unassociated molecules will also associate and form a gel network at low temperatures (and the solubility limit concentration will decrease). It is thought that it will become possible to make them.

The ability of mono-D-compounds (I-1), (I-2), and (I-3) to form gels in cyclohexane or methanol was investigated by SEM observation.

Among these, Fig. 3a shows an SEM photograph of compound (I-1) in cyclohexane, Fig. 3b shows an SEM photograph of compound (I-3) in methanol, and Fig. 3c shows a SEM photograph of compound (I-1) in methanol. SE to ■ photographs of I-21 in methanol are shown, respectively.

All of these formed gels.

Further, from the observation results including the SEX photograph shown in the figure, it was found that the higher the gel-forming ability, the more the fiber network and branching were.

Fiber networks and those with many branches are
Compound (I-1) in cyclohexane in descending order
, Compound (I-1) in methanol, and Compound (I-2) in methanol. At this time, some compounds, such as compound (I-2) in methanol, formed twisted ribbon-like giant aggregates (
(See Figure 3c).

The behavior of earthwork compound (I-1) in methanol is
It was investigated by D spectrum.

The measurement results at 50°C (sol state) and 25°C (gel state) are shown in FIG.

As is clear from Figure 4, in the sol state it is a simple curve and shows no CD at all, but when it forms a gel, it shows a strong CD.
showed that. This suggests that the aggregate has some kind of anisotropic structure.

5) Compound (I-
In order to examine the structures of 1), (I-2), and (I-3) in more detail, they were observed using TEM photographs.

Among these, (1-1) of the compound in methanol
Figure 5a is a TEM photograph of compound (I-1) in cyclohexane, Figure 5b is a TEM photograph of compound (I-3) in methanol, and Figure 5 is a TEM photograph of compound (I-3) in methanol.
They are shown in Figure c.

TEM observations showed that the minimum width was about 100 people. Considering that the molecular length of one compound calculated from the CPK model is approximately 45 molecules, it is assumed that the aggregate is about 2.
It seems that the structural unit is a molecular membrane.

In addition, osmic acid is used to dye the parent xylem black, but in the photo, methanol aggregates are stained only on the outside, while cyclohexane stains the entire area. appears to be oriented outward (surface) in the hydrophilic solvent methanol and inward (internal) in the hydrophobic solvent cyclohexane.

The results of TEM observation are summarized.

The amino acid derivative of the present invention is thought to form a higher-order structure with a bilayer membrane as a constituent unit in a non-aqueous solvent such as methanol or cyclohexane. As is clear from Figure 5c, the higher-order structure in this case is compound (I-2)
There were two types: a ribbon-like one with a helical twist seen in compound (I-3), and a rod-like one seen in compound (I-1).

Each of these higher-order structures (molecular associations) is
It is schematically shown in Figures a and 6b.

In addition, these figures also show cross-sectional views on plane A and plane B, respectively, and both are in a polar solvent such as methanol.

As partially shown in these figures, the direction of the hydrophilic part differs depending on the solvent. In methanol, which has strong polarity, the hydrophilic part faces the outside (surface), and in cyclohexane, which has weak polarity, the hydrophilic part faces the inside (inside) of the higher-order structure. It is considered suitable for

From the above, in the present invention, the gel is formed by the aggregates existing in the sol and some of the non-associated molecules in the solvent growing into large aggregates with many networks and branches as the temperature becomes lower (as the temperature becomes lower). It is thought that it is formed by

Mitatejo 1 Compound (I-1) was used as an oil gelling agent to treat waste oil from household tempura oil. ! ,
was able to solidify the waste oil.

This shows that the product is at a level that can be used as a household waste oil treatment agent.

When compound (I-1) was used as a solidifying agent (gelling agent) to solidify methanol, a liquid fuel, 1
It was possible to completely solidify methanol of 1ρ with an amount of about 0g. It can be seen that the solid fuel thus obtained burns well and is at a level that can be used as a solidifying agent for liquid fuel.

<Effects of the Invention> According to the present invention, novel amino acid derivatives can be obtained.
In this case, synthesis is also easy.

In addition, since it shows gel-forming ability in various non-aqueous solvents,
It is promising as an oil gelling agent, including applications in solid fuel production.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between concentration and temperature in the sol/gel transition of the amino acid derivative of the present invention. FIG. 2 is an NMR spectrum showing the behavior of the amino acid derivative of the present invention in a non-aqueous 18 medium. FIG. 3a, FIG. 3b, and FIG. 3c are photographs substituted for drawings showing the particle structure, and are SEX photographs showing the structure of the amino acid derivative of the present invention in a nonaqueous solvent. FIG. 4 is a CD spectrum showing the behavior of the amino acid derivative of the present invention in a nonaqueous solvent. Figures 5a, 5b, and 5c are photographs substituted for drawings showing the particle structure, and are TEM photographs showing the structure of the amino acid derivative of the present invention in a nonaqueous solvent. Figures 6a and 6b are schematic formulas showing the structures of the aggregates of amino acid derivatives of the present invention, respectively.

Claims (2)

[Claims] (1) An amino acid derivative represented by the following general formula (I). General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc.
3 represents a long chain alkyl group. L is just a bond or 2
represents a valent linking group. X represents an electron-withdrawing group. m is 1, 2, 3 or 4, and n represents a positive integer of 1 or more. When n is 2 or more, R_2 and L may be the same or different. ) (2) A gelling agent characterized by being represented by the following general formula (I). General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the above general formula (I), R_1 represents an aralkyloxycarbonyl group, R_2 represents a hydrogen atom, an alkyl group, or an aryloxycarbonyl group,
3 represents a long chain alkyl group. L is just a bond or 2
represents a valent linking group. X represents an electron-withdrawing group. m is 1, 2, 3 or 4, and n represents a positive integer of 1 or more. When n is 2 or more, R_2 and L may be the same or different. )