JPH05170730A - New intermediate compound and its production - Google Patents

Abstract

PURPOSE:To provide the subject compound useful for producing substituted benzoic acids useful as intermediates for pesticides and medicines including herbicides in an industrially advantageous way. CONSTITUTION:The objective compound of formula I (R<1>-R<4> are each lower alkyl), e.g. 3-methoxy-2-methyl-4-methylthioacetophenone of formula II. The compound of the formula I can be obtained in high yield by reaction of a compound of formula III with a compound of formula R4COCl in the presence of a Lewis acid. A substituted benzoic acid of formula IV can be obtained by acting both halogenating agent and oxidizing agent on the compound of the formula I.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel intermediate compound, a process for producing the same, and a process for producing another intermediate using the intermediate compound. These intermediates are useful as intermediates for agricultural medicine.

[0002]

2. Description of the Related Art 2- (2-Substituted benzoyl) -1,3-
Cyclohexanedione compounds are known to be useful as herbicides, and indeed many patents have been filed. 1,
Not only modification of 3-cyclohexanedione part, but also 2
-Also, the substituted benzoyl moiety was modified, and JP-A-61-2 was used.
Benzoic acid intermediates having three substituents such as 07369 have been reported.

[0003]

An object of the present invention is to provide a novel intermediate compound, a process for producing the same, and a process for producing a substituted benzoic acid using the intermediate compound.

[0004]

Means for Solving the Problems The present invention provides (1)

[Chemical 6] (Wherein R _{1 to} R ₄ are the same or different and each represents a lower alkyl group), (2)

[Chemical 7] (Wherein R _{1 to} R ₃ have the same meanings as described above), R ₄ COCl (wherein R 1
₄ has the same meaning as above. ) The reaction of

[Chemical 8] (Wherein R _{1 to} R ₄ have the same meanings as described above), (3)

[Chemical 9] (Wherein R _{1 to} R ₄ have the same meanings as described above), and a halogenating agent and an oxidizing agent are allowed to act on the compound.

[Chemical 10] (Wherein R _{1 to} R ₃ have the same meanings as described above).

The manufacturing method of the present invention is as follows. Formula [II]
From the reaction of the formula [I], Friedel-Crafts
Reaction, in a solvent such as methylene chloride, chloroform, carbon tetrachloride, dichloroethane, carbon disulfide, nitrobenzene, ZnCl ₂ , SnCl ₄ , TiCl ₄ , AlC
The temperature is from 0 ° C. to the boiling point of the solvent in the presence of a Lewis acid such as l ₃ . ZnCl ₂ is preferable.

The reactions of the formulas [II] to [III] are
The off-form reaction and the oxidation reaction, for example, NaBrO, NaIO, KClO, NaClO as a halogenating agent and an oxidizing agent in an inert solvent such as dioxane as a solvent.
Using an aqueous solution or the like, the reaction temperature is room temperature to the boiling point of the solvent.

[0007]

EXAMPLES Next, the present invention will be specifically described with reference to examples. Example 1 3-Methoxy-2-methyl-4-methylthioacetophenone

[Chemical 11] To 30 ml of methylene chloride, 5.0 g of 2-methyl-6-methylthioanisole, 6.1 g of zinc chloride and 3.5 g of acetyl chloride were added in that order at room temperature, and the mixture was stirred overnight. After the reaction was completed, the reaction solution was put into ice water, extracted with methylene chloride, washed with water, dried, and then concentrated, and the obtained oily substance was separated and purified by column chromatography to obtain 4.1 g of the desired product. It was n _D ^23.5 : 1.5891

Example 2 3-Methoxy-2-methyl-4
-Methylsulfonylbenzoic acid

[Chemical 12] To 25 ml of dioxane, add 5.9 g of 3-methoxy-2-methyl-4-methylthioacetophenone, and add 5% at 70 ° C.
104 g of NaClO aqueous solution was added dropwise over 30 minutes,
Reacted for 3 hours. After completion of the reaction, the product was washed with ether, the aqueous layer was acidified with concentrated hydrochloric acid, extracted with ethyl acetate, washed with water and dried, and then the solvent was distilled off. 5 g was obtained. mp 150-152 ° C

[0009]

The novel intermediate compound can be obtained in high yield,
Substituted benzoic acid can be industrially advantageously obtained using this intermediate. This substituted benzoic acid is useful as an intermediate for the herbicides disclosed in WO91 / 00260 and Japanese Patent Application No. 3-193595.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // C07B 61/00 300

Claims (3)

[Claims] 1. Chemical formula 1 (In the formula, R _{1 to} R ₄ are the same or different and each represents a lower alkyl group.) 2. Chemical formula 2 (Wherein R _{1 to} R ₃ have the same meanings as described above), R ₄ COCl (wherein R 1
₄ has the same meaning as above. ) Is made to react (Wherein R _{1 to} R ₄ have the same meanings as described above). 3. Chemical formula 4 (Wherein R _{1 to} R ₄ have the same meanings as described above), a halogenating agent and an oxidizing agent are allowed to act on the compound. (Wherein R _{1 to} R ₃ have the same meanings as described above).