JPH03190852A - Benzoic acid derivative and production thereof - Google Patents

Abstract

NEW MATERIAL:A benzoic acid derivative shown by formula I (R1 is methyl or ethyl). EXAMPLE:2-(4'-2''-Methoxyethyl-N-allyamino-2'-hydroxybenzoyl)benzoic acid. USE:A raw material for fluoran compound useful to a coloring substance for recording material for pressure sensitive and heat-sensitive recording materials. PREPARATION:A compound shown by formula II is reacted with phthalic anhydride to give a compound shown by formula I. When the fluoran obtained by using the compound, for example, a compound shown by formula III, is used a pressure sensitive recording material, the compound has extremely high solubility in capsule oil and when used as a heat-sensitive recording material, heat- sensitive paper having high whiteness free from base stain in comparison with a fluoran compound obtained by a well-known substance shown by formula IV and has excellent characteristics of coloring in black at a lower temperature and more rapidly than fluoran compound shown by formula V.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel benzoic acid derivative and a method for producing the same.

More specifically, the present invention relates to benzoic acid derivatives, which are important raw materials for producing fluoran compounds useful as recording materials, and methods for producing the same.

[Conventional technology]

Conventionally, a color reaction between a colorless or light-colored electron-donating compound (color-forming compound) and an organic or inorganic electron-accepting substance (color-developing M) is used to mediate external energy such as pressure, heat, or electricity. Methods for recording transmitted information include pressure-sensitive recording, heat-sensitive recording, and energized heat-sensitive recording.

In these recording methods, fluoran compounds are widely used as color-forming compounds.

As benzoic acid derivatives that serve as raw materials for fluoran compounds, compounds of formulas (I[a) and (II[b)], for example, are conventionally known.

(Left below) Using these benzoic acid derivatives as raw materials, formula (I
Va) and fluoran compounds of formula (IVb) have been prepared.

However, the compound of formula (IVa) has the drawback of extremely low solubility in capsule oil when used as a pressure-sensitive recording material, and when used as a heat-sensitive recording material, it cannot be used with a coloring agent such as bisphenol A. When mixed, it itself develops a gray or black-gray color, and when it is applied to paper, it has the disadvantage that only paper colored gray or black-gray (background staining) is obtained.

In addition, the compound of formula (IVb) has a color development temperature that is too high to be used as a heat-sensitive recording material, so it cannot currently be said to have sufficient performance to meet the demands for higher speed and higher density recording. There is a strong desire for color-forming compounds that quickly develop color at low temperatures.

[Problem to be solved by the invention]

An object of the present invention is to provide a benzoic acid derivative useful as a raw material for a fluoran compound, which is suitable for pressure-sensitive and heat-sensitive recording materials, and a method for producing the same, which eliminates the above-mentioned drawbacks.

[Means to solve the problem]

The present inventors have searched for various compounds to solve the above-mentioned problems and have arrived at the present invention.

That is, the present invention provides a benzoic acid derivative represented by the general formula (1) (wherein R1 represents a methyl group or an ethyl group), and this compound, a benzoic acid derivative represented by the general formula (n
) (In the formula (1), R1 and R2 are the same as in the case of general formula (1)) is a method of producing by reacting a 3-aminophenol derivative represented by the formula (1) with phthalic anhydride.

The compound of the present invention is prepared by combining a 3-aminophenol derivative represented by the general formula (I[) (in the formula, R1 represents a methyl group or an ethyl group) and phthalic anhydride in a solvent-free 1. It can be produced by reaction in a solvent such as benzene, toluene, xylene or tetrachloroethylene.

The reaction temperature is preferably in the range of 60 to +40°C, and the reaction time varies depending on the reaction temperature, and is preferably from several hours to several tens of hours. Further, during this reaction, a Lewis acid such as zinc chloride may be added.

The compound represented by the general formula (II) is, for example, a compound in which R2 is a methyl group, for example, 3-N-2-methoxyethylaminophenol obtained from resorcinol and 2methoxyethylamine, for example, allyl chloride or allyl bromide. It can be produced by allylation with an allylating agent such as.

It can also be preferably produced by 2-methoxyethylating 3-allylaminophenol with a 2-methoxyethylating agent such as 2-methoxyethyl-p-toluenesulfonic acid ester.

Further, in the compound represented by the general formula U), in which R2 is an ethyl group, for example, 3-N-2°-ethoxyethylaminophenol is treated with an allylating agent such as allyl chloride or allyl bromide. It can be produced by allylation.

It can also be preferably produced by 2-ethoxyethylating 3-allylaminophenol with a 2-ethoxyethylating agent such as 2-ethoxyethyl-p-toluenesulfonic acid ester.

[Action of the invention]

The compounds of the present invention are very useful as raw materials for producing novel fluoran compounds as color-forming substances for recording materials.

Fluoran compounds produced using the compounds of the present invention,
For example, the compound of the following formula (V) has extremely high solubility in capsule oil when used in pressure-sensitive recording materials;
And when used in a heat-sensitive recording material, a thermal paper with high whiteness without background staining can be obtained compared to the case where the compound of formula (IV) is used, and furthermore, it can be used at a lower temperature than the compound of formula (IVa). It has an excellent feature of quickly turning black.

〔Example〕

EXAMPLES Hereinafter, the compounds of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 [Compound in which R1 is a methyl group in general formula (I)] 3-N-2-methoxyethylaminophenol produced from resorcin and 2-methoxyethylamine was allylated with allyl chloride. After heating 45 g of N-2-methoxyethyl-N-allylaminophenol and 49 g of phthalic anhydride in 100 ml of toluene for 10 hours, the reaction solution was washed twice with 200 ml of warm water, the toluene layer was separated, and further Toluene 200- and 40% Na
An OH aqueous solution was added, and the mixture was heated at 60 to 70°C for 2 hours.

Thereafter, after being left at room temperature overnight, the precipitated sodium salt was filtered, washed with toluene, and dried.

After dispersing the sodium salt in 400 ml of water and adjusting the pH to 6 with a 10% Hen aqueous solution, the precipitated solid was collected, washed with water, and dried to obtain 2(4'-2''-methoxyethyl-N-allylamino-2-hydroxybenzoyl)benzoyl. 30 g of acid were obtained as cream-colored crystals.

Yield 4096, melting point 103-107°C Example 2 [Compound in which R1 is an ethyl group in general formula (I)] In Example 1, 3-N-2°-methoxyethyl-N
Instead of allylaminophenol, 3-N-2ethoxyethyl-N-allylaminophenol (- general formula (It
2(4'-N-2"-
Ethoxyethyl-N-allylamino-2hydroxybenzoyl)benzoic acid was obtained in a yield of 4596 as cream-colored crystals.

Melting point 121-123℃

Claims (2)

[Claims] (1) Benzoic acid derivative represented by general formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R_1 represents a methyl group or an ethyl group). (2) General formula (II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) A 3-aminophenol derivative represented by (in the formula, R_1 represents a methyl group or an ethyl group) and phthalic anhydride. A method for producing a benzoic acid derivative represented by the general formula (I) according to claim (1), characterized in that the benzoic acid derivative is subjected to a reaction.