JPS5837301B2 - Seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel method for producing a photochromic compound, and more specifically, the present invention relates to a method for producing a novel photochromic compound, and more specifically, β.β-diphenylpropionic acid compounds are nitrated with fuming nitric acid in the presence of concentrated sulfuric acid to produce β−
The present invention relates to a method for producing bis(2,4-dinitrophenyl)propionic acid compounds.

It is known that β·β-bis(2,4-dinitrophenyl) acetate methyl or ethyl ester exhibits photochromism, and research on the coloring mechanism, for example, by Glenn H. Photochromism (Technique) by Glenn H. Brown
s of Chemistry Series Vol.
．． II [ ) 5 8 0 - 588 pages (Wiley
-Int-Ersscience, 1971).

However, β・β-bis(2,4-dini-1-lophenyl)acetic acid is an extremely unstable compound and easily decomposes when heated, turning into bis(2,4-dinitrophenyl)methane. Research on the photochromism of this family of compound derivatives has also been limited to the aforementioned methyl or ethyl esters.

As a result of intensive research aimed at stabilizing the above-mentioned β,β-bis(2,4-dinitrophenyl)acetic acid, the present inventors discovered a new compound in which a methylene group is inserted between the methine carbon and the carboxyl group. The compound β・β-bis(2,4-dinitrophenyl)propionic acid is an extremely stable compound, and various derivatives can be easily synthesized.
It has been found that -bis(2,4-dinitrophenyl)propionic acid itself and its esters exhibit photochromism similar to β·β-bis(2,4-dinitrophenyl)acetic acid ester.

The β·β-bis(2,·4-dinitrophenyl)propionic acid compound according to the present invention is a β·β-diphenyl compound represented by the general formula [wherein R represents CnH2n+1 (however, n=o to 4)] Obtained by nitrating a propionic acid compound with fuming nitric acid in the presence of concentrated sulfuric acid.

The starting material β·β-diphenylpropionic acid compound of the present invention is already known and can be obtained, for example, by the synthesis example described below.

It should be noted that this joint example shows one example, and the present invention is not limited thereby.

[Synthesis example of β/β-diphenylpropionic acid] 570TrL of dry benzene was placed in a 1L 4-day flask equipped with a reflux condenser with a calcium chloride tube, a thermometer, and a stirrer.
and cinnamic acid 45? (0.3 mole) was added and stirred to dissolve.

Next, while cooling this with ice water, anhydrous aluminum chloride 7
51 was added and stirred while cooling for 5 hours, and the reaction mixture was further left at about 5° C. for about 30 hours.

After the reaction was completed, 500 ml of diluted hydrochloric acid was added to the reaction mixture, transferred to a 2 liter eggplant-shaped flask, water vapor was passed through it to remove unreacted benzene, and the precipitate was filtered while hot.
It was dried and recrystallized from benzene.

Yield: 44.91%, yield: 65.4%, melting point: 155°C.
White crystals of β-diphenylpropionic acid were obtained.

The reaction formula is shown below.

[Synthesis example of ethyl β/β-jinenylpropionate]

In a 200d eggplant-shaped flask, add 35 g (o.16 mot) of β-β-diphenylfuropionic acid, 8 ml of ethyl alcohol.
0ml! (1.4 mol) and 12 mA of concentrated sulfuric acid were added, and a reflux condenser was attached, and the mixture was heated under reflux for 6 hours.

Transfer the resulting reaction mixture to a separatory funnel and add approximately **1 cup of cold water.
Add 00ml of diethyl ether, stir, and add 50ml of diethyl ether.
7 was added and stirred well, the aqueous layer was removed, washed with 1% aqueous sodium carbonate solution, dried over anhydrous sodium sulfate, and distilled under reduced pressure to 167.5°C/4 mmH.
Ethyl β-diphenylpropionate 40.1f (yield 7
6%).

The reaction formula is shown below.

The photochromic compound of the present invention is produced by nitrosating the β/β-diphenylpropionic acid compound obtained by the above method using fuming nitric acid in the presence of concentrated sulfuric acid. This will be described in detail in the following examples.

Example 1 330 TL of fuming nitric acid was added to a 1 L 4-day flask equipped with a thermometer, stirrer and Allyn condenser.
Cooled to about -18°C.

β・β diphenylpropionic acid 23 in this? (0.
1 mol) was added little by little to prevent the temperature from rising, stirred for 1 hour, and added concentrated sulfuric acid 3782 and 50% oleum 17
9 g of the mixture was added, stirred at room temperature for 6 hours, and left overnight to complete the reaction.

Pour the resulting reaction mixture into a beaker containing ice water,
The precipitate that had separated out was filtered and dried under vacuum.

This was recrystallized twice from glacial acetic acid, yielding 17.5tiI, pale yellow crystals with a yield of 42% and a melting point of 232°C.
2,4-dinitrophenyl)propionic acid was obtained.

The elemental analysis values are shown below. C (To) H% N
Wheel calculation value 44.35 2.84 13.79
Actual value 44.24 2.14 13.47
The compound obtained above was dissolved in various organic solvents to a concentration of 5 × 10-mol/l, and after making it basic by adding 3 drops of pyridine to this solution and 1 cc of this solution, it was heated at -70°C at 500 W. It was irradiated with ultraviolet rays from an ultra-high pressure mercury lamp for 30 seconds and observed for color changes.

The results are shown in Table 1 and show good photochromism.

Example 2 15 liters of fuming nitric acid was added to a 5001'fLl 4-hole flask equipped with a thermometer, stirrer, dropping funnel and Alincon*denser, cooled to -18°C, and the β/β-diphenyl obtained above was added. Add 12 g of ethyl propionate (0.047 mol) little by little to prevent the temperature from rising, then add a mixture of 189 g of concentrated sulfuric acid and 391 g of 50% fuming sulfuric acid at the same temperature, and stir at room temperature for 4 hours. , and then left overnight to complete the reaction.

The reaction mixture was poured into a beaker containing ice water, and the precipitate was filtered with suction, dried, and recrystallized twice with a 1:3 mixture of water and ethanol to give β.
2.51 (yield: 12%) of ethyl β-bis(2,4-dinitrophenyl)propionate was obtained.

The results of elemental analysis are shown below.

C(3) H% N(3) Calculated value 47.02 3.25 12.89
Actual value 46.89 3.20 13.16
β・β-bis(2,4-dinitrophenyl) obtained above
Ethyl propionate was dissolved in various organic solvents to give mol/J of MK, and this solution and a solution made basic by adding additives to this solution were exposed to ultraviolet rays from an ultra-high pressure mercury lamp at a temperature of 70 to -20°C for 30 minutes. It was irradiated for seconds and the color change was observed.

The results are shown in Table-2.

The above results also show that the compound according to the present invention exhibits good photochromism.

Ethyl mata β, β-bis(2,4-dinitrophenyl)propionate was dissolved in acetone to a concentration of 2 x 10-3 mol/l, 3 drops of pyridine was added to 5 cc of this solution, and the mixture was exposed to ultraviolet light for 1 minute. The absorption spectrum after irradiation is shown in FIG. 1 in comparison with that without irradiation.

As a result, light absorption was clearly observed in the irradiated specimen compared to the unirradiated specimen.

[Brief explanation of drawings]

Figure 1 shows β・β-bis(2,4-dinitrophenyl)
Svector of an acetone solution of ethyl propionate. 1: Not irradiated, 2: After irradiation.

Claims (1)

[Scope of Claims] [In the formula, R represents CnH2n+1 (where n=O to 4)] A β/β-diphenylpropionic acid compound represented by the following is nitrated with fuming nitric acid in the presence of concentrated sulfuric acid to obtain the general formula [ 1. A method for producing a photochromic compound, characterized in that it is a β·β-bis(2,4-dinitrophenyl)propionic acid compound represented by the formula, wherein R represents CnH2n+1 (n-O to 4).