JPS59204183A - Dicarboxylic acid monoester and its preparation - 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 present invention relates to a dicarboxylic acid monoester represented by the general formula (1) and a method for producing the same. In the above formula, R1 is a hydrogen atom or a methyl group, an ethyl group, a propyl group, a butyl group, Play with lower alkyl groups
R2 and R3 are the same or different hydrogen atoms; lower alkyl groups such as methyl, ethyl, propyl, and butyl; or lower alkoxy groups such as methoxy, propoxy, and butoxy groups; or
or R2 and R3 together -C)l=cH-CH=
Forms a CH- group. R4 represents a 7'A elementary atom or a protective group. As the protecting group, any commonly used protecting group may be used as long as it achieves the purpose of protecting the water-bleached group, such as acetyl group, phlopionyl group, butyryl group, benzoyl group; Examples include a t-butyl group, a triphenylmethyl group, a be/cyl group, a t-butyl group, a triphenylmethyl group, a t-butyl group, and a t-butyl group. R5, R6, R7 and R8 are the same or different, each a hydrogen atom or a methyl group, an ethyl group, an alkyl group such as a propyl group, a butyl group, etc.
s, or R5 and R6 or R7 and R8 together eliminate the CH2= group. R5 and R7 together create a rumored bond, or R6 and R8 together 3 group, -CH2C=CHCH2- group, -CH2CH2CH
The dicarboxylic acid monoester represented by the 2CH2- group and the general formula (I) provided by the present invention is a new compound that has not been described in any known literature. Among these dicarboxylic acid monoesters, those in which R4 in the general formula (1) is a hydrogen atom have an excellent antioxidant effect, and are suitable for use in oxygen-sensitive organic materials, such as oils and fats, rubber products, plastics, and processing. It is useful as an antioxidant for foods, etc. Further, when R4 in the general formula CI) is a protecting group, a compound having the above-mentioned antioxidant effect can be obtained by replacing this protecting group with a hydrogen atom by a conventional method.

Recently, vitamin E has attracted attention as a highly safe antioxidant, but it has not yet become a general-purpose antioxidant because it is relatively expensive and is easily oxidized and colored.

As a result of intensive research to develop a new antioxidant that surpasses vitamin E, the present inventors found that the dicarboxylic acid monoester represented by the general formula The present inventors have discovered that these dicarboxylic acid monoesters can be easily produced as precursors of compounds having an anti-oxidation effect, and have thus arrived at the present invention.

9'' invention (according to this, general formula (n) 1 shi: + (A, R1, R2 and R3 are the same as in general formula (I), t711+2, f( is general formula (1) A 0 representing a water atom or a protective group, which is the same as or different from R4 in
] 2-substituted ethyl alcohol and general formula (m)
[Wherein, R5, R6, R7, R8 and n are general formula (I)
has the same meaning as in. ] The dicarboxylic acid monoester represented by the general formula (1) can be produced by reacting with the dicarboxylic acid anhydride represented by the formula (1). This reaction can be carried out under the same conditions as in the usual reaction between an alcohol and an acid anhydride. For example, 2- shown in -ff formula (1)
Substituted ethyl alcohol and the dicarboxylic acid anhydride represented by the general formula (m) in approximately equimolar equivalents to the 2-substituted ethyl alcohol, trabenzene, toluene, chloroform,
In an inert medium such as dichloroethane or without a solvent,
In the absence of a catalyst, preferably in the presence of a tertiary amine such as pyridine or triethylamine or an acid such as sulfuric acid or p-toluenesulfonic acid in an amount of 2 molar equivalents or less relative to the 2-substituted ethyl alcohol, at room temperature or with heating. The desired dicarboxylic acid monoester represented by general formula (1) can be obtained by carrying out the reaction.

The dicarboxylic acid monoester represented by general formula (I) obtained by the above ester synthesis reaction can be separated and recovered by a conventional method. For example, water is added to the reaction mixture, then extracted with ether, the extract is washed with water, dried, concentrated with a solvent, and then the residue is reboiled or dried! - The dicarboxylic acid monoester represented by the monocatalytic formula (I) can be removed by purification by chromatography.

Most of the 2-containing ethyl alcohol represented by the general formula (11) used in combination with J, 'l', and f are compounds known per se. According to the method previously used by the nine unsuccessful parties (see Publication No. 145282/1982), the general formula (IV) was obtained, where it, R1, R2 and R3 are the general Formula C
HI) has a circular meaning. ] It can be easily obtained by reacting hydroquinone or its derivative represented by K with 4-methyl-5,0-dihydro-2H-bilane in the presence of a Lewis acid (see Japanese Patent Application No. 83,654/1989). (Refer to book) 0 Lewis acids used in this condensation reaction include, for example, boron trifluoride ether complex, aluminum chloride, aluminum bromide, ferrous chloride, ferric chloride, stannous chloride, stannic chloride, Zinc chloride, sulfuric acid, p-toluenesulfonic acid, etc. can be mentioned, but the amount of Lewis acid used is preferably aluminum chloride, boron trifluoride/ether complex, and hydroquinone represented by the general formula (IV) or its 0.1 to 2 times the molar amount of the derivative, preferably 0.5 to 1.0
This is twice the molar amount. This condensation reaction is preferably carried out in a solvent, such as 1,2-dichloroethane, dichloromethane, chloroform, 1. , 1.2- trichloroethyl V
Hydrocarbons such as benzene, toluene, n-hexane, ligroin, cyclohexane, n-hexane, ligroin; Nitrogen-containing compounds such as nitromethane, nitrobenzene, benzonitrile, acetonitrile; Methyl ethyl ketone, acetic acid Oxygenated compounds such as ethyl, butyl acetate or mixtures thereof I
Although F/l can be used as a solvent, 1,2-dichloroethane is particularly preferred. The amount of solvent used is according to general formula (IV)
About 2 for hydroquinone or its derivatives represented by
~100 times the weight, or approximately 5 to 20 times the weight (-1□). This condensation reaction is usually carried out at -40'C to 150°C, preferably -
The process is carried out at 0°C to 100'C. The 4-methyl-5,6-sihydro-2H-bilane used here is used in the production of inoprene from inbutene and formalin.
It can also be synthesized by reacting secondary butanol with an aqueous formaldehyde solution in the presence of an acid catalyst, and is easily available at low cost.

The dicarboxylic acid anhydride represented by the general formula (the dicarboxylic acid anhydride shown in the figure) is a known compound.

The present invention will be specifically described below with reference to Examples and Test Examples.

Example 1 3.4-dihydro-2-hydroquinethyl-2,5°7
．． 8-tetramethyl-2H-benzobilan-6-ol 101? , Anhydrous Konori Awakening 4.0? , p-) luenesulfonic acid 0.6? and toluene], OOrrtl. The mixture was stirred at room temperature overnight and then heated to reflux for 2 hours. The sheathed reaction solution was poured into water and extracted with diethyl ether. Add an aqueous sodium bicarbonate solution to the extract and extract the target product into the aqueous layer. The resulting aqueous layer was washed with diethyl ether, acidified with dilute hydrochloric acid, and extracted with diethyl ether. After washing the ether extract with water and drying it over anhydrous magnesium sulfate, the low-point products were distilled off under reduced pressure, and the resulting concentrated solution was purified by silica gel column chromatography (from the above, it had the following physical properties). co-phosphoric acid mono(2-(3,4-dihydro-6-hydroxy-2,
7.82 pieces of 5,7,8-tetramethyl-2H-benzopyranyl)ethyl ester were obtained (yield: 56).

FD mass spectrum, [M] 350HMS.

N1\'LR spectrum (90MHz) δCDQ! 3
'122 (s, :5i71); 1.
65~z, 2 (m, 13M); 2.45-2
．． 73 (”+614): 4.0 b ~ 4
．． 55 ("+2"') ;711~80(b
r, b, 2J disaster) 41 Shiori 2 3.4-dihydro-2-hydroxyethyl-2,5゜7
．． 8-tetramethyl-2kl-benzobilan-6-ol', ), 5 ql pyridine 0.8'? , 1.2
- To a solution consisting of 50 ml of dichloromethane, 1.07 (l Q + nrnol) f of phosphoric anhydride was added, and after stirring at room temperature overnight, 211,' The reaction solution was diluted with diluted hydrochloric acid to add 1 ton of dienalue.
Extracted with chill. The extracted aqueous layer was washed with water (~) After this, aqueous sodium bicarbonate was added to the mixture, and the target product was extracted into the aqueous layer. K-: After washing the aqueous layer with diethyl ether, Salt was added to the mixture, followed by extraction with L and diethyl ether.

Extraction (1 isocarbonized with water, dried over anhydrous magnesium chloride, evaporated under pressure, and the resulting concentrate is purified by chromatography. , succinic acid mono(2-(3,4-dihydro-6-
Hydroxy-2,5,7,8-tetramethyl-2H-penthyranyl)ethyl]ester'i3.21F was obtained (
Yield: 91 cycles).

Examples 3 to 6 The reaction and separation and recovery were carried out in the same manner as in Example 2, except that IQ mmol of dicarboxylic acid anhydride shown in Table 1 was used instead of 10 mmol of succinic anhydride in Example 2. A dicarboxylic acid monoester was obtained.

The results are shown in Figure 1.

Table 1 4.0-4.5 (m, 2M); 5.0-6.0 (m, 2H) 2.6 (t, J=7Hz, 2)i); 4.23-4.
7 (m, 2H); 6.17-6.57 (m, 2H);
:E(); 6.8-8.0 (m, 2H) 2.57 (t, J=7Hz, 2M); 3.7 (s, 2H); 4.1.5-4.6 (m , 2'H); 5.8~7
．． 2 (rn,, 41()2.56(t, J=7
Hz, 2H); 4.27-4.76 (rn, 2
fi); 7.0 (br, s, 2H) 7.47-8.0 (m, 4K) Example 7 C) li In Example 2, 3,4-dihydro-2-hydroxyethyl-2,5,7 , 8-tetramethyl-2H-benzobyran-6-ol2.52 instead of 2-(6-benzyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-benzopyranyl]ethanol3 By carrying out the reaction and separation and recovery in the same manner as in Example 2 except for using .42, succinic acid mono(2-(
6-benzyloxy-3,4-dihydro-2,5,7,
4.1f of 8-tetramethyl-2H-benzopyranyl)ethyl]ester was obtained (yield: 93).

FD mass spectrum: [M]+44O NMR, <Pect/, (90MH2)6 l11M5
.

CDα3°1.22 (S, 3H); 1.65-2.25 (m, 13
H); 2.4-2.8 (m, 6H); 4.07
~4.56 (m, 2H); 4.7 (S, 2
M); 7.2-7.6 (ml 5H); 10.
8 (br, s, IH) 2 (S) 8 Back IM (Nil 2 F, 3,4-dihydro-2-hydroquinethyl-2,5,7,8-tetramethyl -2H-benzobyran-6-ol 2 instead of 251
-(6-aceto-xy-3,4-dihydro-2-methyl-2H-benzovira,=)ethanol 2.57'! z
By carrying out the VC reaction and separation and recovery in the same manner as in 112, a succinic monomer (2-(6-acetoxy-3,4-
dihuman'ry-2-methyl-2M-benzopyranyl)
3.12 ethyl]esters were obtained (yield: 86 cm).

FD@J, (Spectrum: (R4) + 350 Examples In Example 2, succinic anhydride IQmmolO was replaced with fuclohexane-1,2-dicarboxylic anhydride, ■-cyclohexane-1,2-dicarboxylic anhydride , 4-fuclohexene-1,2-dicarbofnorbornane-2,3
-Dicarboxylic acid-free 711,5-norbornene-2,3-
Dicarboxylic anhydride, 4-methyl-4-cyclohexene-1,2-dicarboxylic anhydride, 1, 4, 5, 6
, 7. 7-hexachlor-5-norbornene-2,
The corresponding dicarboxylic monoesters were obtained by carrying out the reaction and separation and recovery in the same manner as in Example 2, except that 1Q mmol of 3-dicarboxylic anhydride and ntraconic anhydride were used. The results are shown in Table 2.

(1') (r') Table 2 Examples 17-23 In Example 2, 3,4-dihydro-2-hydroxyethyl-2,5,7,8-tetramethyl-2H-benzopyran-6-ol 2 The corresponding succinic acid monoesters were obtained by carrying out the reaction and separation and recovery in the same manner as in Example 2, except that 10 mmol of the 2-substituted ethyl alcohol shown in No. 3-2 was used instead of .5f. The results are shown in Table 3.

Table 3 Test Removal Examples 1 to 19 Add 1'f of the test compound shown in No. 4 ice to linol il ethyl.
: Wow, f'L is O for ethyl linoleate 1001
Fl 207 was added and mixed 1 to 1 to prepare a sample fl 1 solution.

A OM (An
ti Oxygenmar; l + oa ,) Trial device ζ
under AOM conditions (9'7.8°C, )'1j air2.
33 °C/see,), and the time for POV (peroxide!iwasen1) to reach 1 fl (l meq/kCy) was measured.

The results are shown in Table (+j;, , i).

1 Additive-free 01

Claims (1)

[Claims] 1 General formula [wherein R1 represents a hydrogen atom or a lower alkyl group,
-, R2 and R3 are the same or different, each representing a hydrogen atom, a lower alkyl group or a lower alkokyne group,
Or R2 and R3 together form -CH=CI(-CH-
Forms a CH- group. R4 represents a hydrogen atom or a protective group. R5, R6, R7 and Rs hali5]-, or each represents a water purple atom or an alkyl group, or R
Do 5 and R6 or R7 and R8 together represent a CH2- group? Do R5 and R7 together represent a single bond? R6 and R8 together represent -C)1=CH-CI(
=CH- group, -CH2C-stopped CHCH2- group, and X represent a halogen atom. nFiO represents an integer of 2. ] A dicarboxylic acid monoester represented by 2. General formula (wherein R represents a hydrogen atom or a mining group, R1 represents a hydrogen atom or a lower alkyl group, R2 and R3 are the same -
Alternatively, each represents a hydrogen atom, a lower alkyl group, or a lower alkoxy group. Or R2 and R3 together form -Cf (=CI:L-C
2-substituted ethyl alcohol represented by H-=C1 (forms a - group) and the general formula (wherein,
R5, R6, R7 and R8 are the same or different and each represents a hydrogen atom or an alkyl group, or R5 and R6 or R7 and R8 together represent CH2-4.R5 and R7 together represent a single bond R6 and R8 together represent -CH=H3 group, C)12c=cHcH2- group, -CH2(J(2
It represents a cH+cH2- group or a -cxcx-cxcx- group, and X represents a halogen atom. 11 represents an integer from 0 to 2. [In the formula, R1, R2, R3, R5, R6, R7, R8 and n represent the same meanings as above, R4 is R and A method for producing a dicarboxylic acid monoester represented by ○) representing a hydrogen atom or a protective group, which is the same or different.