JPH03393B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thiophene compound which is important as an intermediate for dyes or agricultural chemicals, and a method for producing the same.

More specifically, the formula (1) of the present invention (In the formula, R represents hydrogen or formyl, X represents cyano or lower carbalkoxy, and Y represents hydrogen or nitro.) A thiophene-based compound represented by the following.

(2) A compound represented by the formula HSCH ₂ COOR ₁ (2) (wherein, R ₁ represents lower alkyl) and a compound represented by the formula NCCH ₂ X (3) (wherein, X represents cyano or COOR ₁ , and R ₁
means the same as above) is condensed and ring-closed to form the formula (In the formula, X means the same as above.) A compound represented by the formula (R ₂ ) ₂ NCHO (5) (wherein, R ₂ represents lower alkyl) was obtained. By reacting phosphorus oxychloride in dialkylformamide, (In the formula, R ₂ represents lower alkyl, and X means the same as above.) It is characterized by obtaining a compound represented by the following formula, and then hydrolyzing or nitrating this compound and then hydrolyzing it. formula (In the formula, R represents hydrogen or formyl, and X and Y have the same meanings as above.) A method for producing a thiophene compound represented by the following.

(3) Equation (In the formula, X represents cyano or COOR ₁ , R ₁
A compound represented by the formula (R ₂ ) ₂ NCHO (5) (wherein R 2 represents lower alkyl) is reacted with phosphorus oxychloride in a dialkylformamide (wherein R ₂ represents lower alkyl) to obtain the formula (In the formula, X and R ₂ have the same meanings as above) is obtained, and then this compound is hydrolyzed or nitrated and then hydrolyzed. (In the formula, R, X and Y have the same meanings as above.) A method for producing a thiophene compound represented by the following.

Regarding.

The thiophene compound of formula (1) of the present invention is novel and can be produced by the following method.

First, to produce the compound of formula (4), the compound of formula (2) and the compound of formula (3) are mixed in an alcohol such as methanol or ethanol with triethylamine, diethylamine,
For example, from 10℃ to 80℃ using a base such as pyridine as a catalyst.
It can be easily condensed and ring-closed by heating and stirring with water, and can be precipitated and recovered by diluting with water and neutralizing with acid.

Next, the compound of formula (6) can be obtained, for example, as follows. That is, the compound of formula (4) is dissolved in the compound of formula (5) and about 1 molar equivalent of phosphorus oxychloride, for example 1.0 to
When 1.05 molar equivalent is added and stirred with heating at room temperature to 10°C, the compound of formula (6) is easily produced, so the reaction solution is poured into ice water, neutralized with alkali, and the above compound is precipitated and collected. In this process, 1 molar equivalent of phosphorus oxychloride is appropriate, and if 2 to 4 molar equivalents of phosphorus oxychloride are used, the formula It is surprising that the reaction is stepwise and almost pure compound of formula (6) is obtained using 1 mole of phosphorus oxychloride.

Next, the compound of formula (1) can be obtained from the compound of formula (6) as follows. That is, when the compound of formula (6) is heated in an acidic environment (for example, from 50°C to the boiling point of alcohol) using an aqueous solution of sulfuric acid or hydrochloric acid in a lower alcohol, it is easily hydrolyzed to form a 2-amino-thiophene derivative (in formula (1)). A compound in which R=hydrogen) can be obtained. In addition, the compound of formula (6) can be prepared using an aqueous solution of an alkali in a lower alcohol at a temperature of, for example, 50 to 100°C.
When heated and hydrolyzed, 2-formylamino-
Thiophene derivatives (compounds in which R is CHO in formula (1)) can be obtained. Further, a compound in which Y in formula (1) is a nitro group can be nitrated by a known method, for example, by dissolving the compound of formula (6) in sulfuric acid, adding a mixed acid dropwise thereto and stirring at 0±5°C. (use,
The amount of nitric acid in the mixed acid may be about 1 molar equivalent). Next, the reaction solution is poured into ice water to remove the precipitated nitro compound. Finally, acidic hydrolysis in alcohol as described above yields a 2-amino-5-nitrothiophene derivative, and alkaline hydrolysis yields a 2-formylamino-5-nitrothiophene derivative.

Next, examples of the compound of formula (2) used in the present invention include SHCH ₂ COOCH ₃ , SHCH ₂ COOC ₂ H ₅ ,
Examples include SHCH ₂ COOC ₃ H ₇ and SHCH ₂ COOC ₄ H ₉ . Also, as a compound of formula (3)
NCCH ₂ CN, NCCH ₂ COOCH ₃ ,
NCCH ₂ COOC ₂ H ₅ , NCCH ₂ COOC ₃ H ₇ ,
Examples include NCCH ₂ COOC ₄ H ₉ .
Furthermore, examples of the compound of formula (5) include dimethylformamide and diethylformamide.

The compound of formula (1) of the present invention is useful as a diazo component of red to blue azo dyes and as an intermediate for agricultural chemicals.

Next, the present invention will be described in detail with reference to Examples, where "parts" and "%" refer to "parts by weight" and "% by weight."

Example 1 40 parts of ethanol, 13.2 parts of malonitrile, and 24 parts of ethyl mercaptoacetate are dissolved with stirring, and 15 parts of triethylamine is added dropwise over 30 minutes at 15°C or lower. 15±2
Stir at ℃ for 1.5 hours and then at 40±2℃ for 1 hour to achieve condensation. Pour into 300 parts of ice water and add 15% hydrochloric acid to precipitate crystals. When separated, washed with water and dried, the formula (A)
25.8 parts of 2-imino-3-cyano-2,3,4,5-tetrahydrothiophene (-4) are obtained.

mp189−191℃ 120 parts of dimethylformamide and the above imino compound
Add 21 parts and stir to dissolve, then add 24.0 parts of phosphorous oxychloride dropwise at below 10°C over about 20 minutes. Stir at 15°C ± 2° for 1 hour and at 40 ± 5°C for 1 hour, then pour into 1300 parts of ice water. Add about 110 parts of 15% caustic soda solution and pH=
Neutralize to 5-6. The mixture was stirred for 3 hours at 10±2°C, and the precipitated crystals were washed separately with water.

22 parts of an amidine derivative of the following formula (b) are obtained.

The parent peak of the mp86-88°C mass spectrum shows 213, which is consistent with the following formula (b).

15 parts of the above amidine derivative were dissolved in 70 parts of ethanol, 7 parts of concentrated sulfuric acid (96%) was added, and the mixture was refluxed for about 1 hour. Then, pour into 400 parts of ice water and neutralize to pH=7-8 by adding an aqueous solution of caustic soda. After extracting from this aqueous solution using ether and drying with anhydrous sodium sulfate,
Remove the ether under reduced pressure. 10 parts of 2-amino-3-cyano-4-chloro-thiophene of the following formula (c) are obtained as an oil.

The parent peak of the mass spectrum is 158, which corresponds to the following formula (c), and the IR spectrum is (740, 850, 900,
1095, 1260, 1400, 1490, 1600, 1730, 2200,
2950, 3150, 3300, 3400 cm ^-1 ). Also, in p-dimethylbenzaldehyde and alcohol,
When condensed with a piperidine catalyst, a Schiff base of the following formula (d) is obtained and exhibits a mp of 182-184°C.

Dissolve 5.5 parts of the amidine derivative of formula (b) in 40 parts of ethanol and dropwise add 20 parts of an 8% aqueous solution of caustic soda at 10°C or below. After stirring for 2 hours at 25±2°C and 30 minutes at 50±5°C, the mixture was poured into 200 parts of ice water. Afterwards, add dilute hydrochloric acid to neutralize and separate the precipitated crystals.

A 2-formylamino compound of the following formula (e) was obtained, the parent peak of the mass spectrum was 186, and the mp was 102-104°C.

Example 2 22.6 parts of ethyl cyanoacetate, 24.0 parts of ethyl mercaptoacetate, and 40 parts of ethanol are added dropwise to 15 parts of triethylamine at 10° C. or below while stirring. Stir at 15±2°C for 1 hour and at 45±2°C for 1 hour. When this was poured into 400 parts of ice water and 30 parts of 15% hydrochloric acid was added to neutralize it to pH=5, 2-imino-3-carboethoxy-2,3,4,5-tetrahydrothiol of the following formula (f) Ofenone (-4) precipitates, so separate, wash with water, and dry.
You will get 33 copies. mp150−152℃ Similarly, if 19.8 parts of ethyl cyanoacetate is used instead of 22.6 parts of ethyl cyanoacetate, 2-imino-3-
30 parts of carbomethoxy-2,3,4,5-tetrahydrothiophenone (-4) are obtained. mp177
-178℃ Add the above imino compound to 100 parts of dimethylformamide.
28 parts of the solution was dissolved with stirring, and 24 parts of phosphorus oxychloride was added dropwise at a temperature below 10°C over about 30 minutes. After stirring at 15±2°C for 1 hour and at 50-60°C for 1 hour, the mixture was poured into 1300 parts of ice water. Add approximately 140 parts of 15% caustic soda to pH=6
Neutralize until complete and stir for 3 hours. Amidine of the following formula (g) is precipitated as an oil, which is then washed with water to obtain about 30 parts. The parent peak of this mass spectrum is 260, which is consistent with the compound of formula (g).

15 parts of the above amidine were dissolved in 100 parts of alcohol, 10 parts of concentrated sulfuric acid was added, and the mixture was refluxed for 1 hour. After pouring into 400 parts of water, add caustic soda solution to neutralize to pH=6-7. This aqueous solution is extracted with ether, anhydrous sodium sulfate is added to the ether solution, and after drying, the ether is removed under reduced pressure. 9.5 parts of amino-thiophene of the following formula (H) is obtained in the form of an oil. The parent peak of the mass spectrum is
205, which matches equation (H), and the IR spectrum is (730,
850, 905, 1090, 1190, 1260, 1330, 1370,
1490, 1590, 1650, 1740, 2300, 2970, 3130,
Absorption was observed at 3450 cm ^-1 ).

Further, 15 parts of the above amidine was dissolved in 100 parts of alcohol, 30 parts of a 20% aqueous sodium hydroxide solution was added, and the mixture was refluxed for 1 hour. This reaction solution was poured into 500 parts of ice water and neutralized to pH=5 by adding hydrochloric acid. The lumylamino compound of the above formula (I) precipitates and is separated, washed with water and dried. 10.8
The parent peak of the mass spectrum shows 233, which corresponds to formula (li), and shows an mp of 77-78°C.

Further, 15 parts of amidine of the above formula (g) was dissolved in 100 parts of alcohol, 10 parts of 66Bi sulfuric acid was added, refluxed for 1 hour, cooled, and further 50 parts of 20% caustic soda was added to the solution at 75±2°C.
Heat for 4 hours. Pour into 300 parts of ice water and add concentrated hydrochloric acid to neutralize to pH=3. The residue is removed separately, the liquid is extracted with ether, and the ether is removed under reduced pressure. Thiophenecarboxylic acid of the above formula (nu) is obtained, and the parent peak in the mass spectrum is 177
and mp123° (decomposition).

Example 3 20 parts of amidine of the formula (g) described in Example 2 are added to 180 parts of 66Bi sulfuric acid and stirred at 10°C or lower to dissolve.
A mixed acid consisting of 4.7 parts of concentrated nitric acid (d=1.52) and 10 parts of concentrated sulfuric acid was added dropwise at -5±2°C over about 1 hour, and the mixture was further stirred for 30 minutes. After pouring into 700 parts of ice water, separate the nitro compound that precipitates in a slightly Harz shape and wash with water. Add 100 parts of alcohol to dissolve it, add 10 parts of concentrated sulfuric acid, and reflux for 4 hours. After that, remove the residue by heating, pour the alcohol solution into 500 parts of ice water, and add 20 parts of common salt.
part and stir. A Harz-like nitrothiophene derivative of the following formula (R) is obtained. When recrystallized from methanol-acetone (8:2)
Shows mp216-219℃. Nitrothiophene (wa)
is dissolved in acetic acid-propionic acid (4:1) by a conventional method, diazotized by adding nitrosyl sulfuric acid at 0±2°C, and coupled with an aqueous solution of NN-diethyl-acetomethamine to obtain a monoazo dye of the following formula (F). is obtained, exhibiting a λmax of 618 nm (85% acetone solution), and dyes polyester fibers blue.

Claims (1)

[Claims] 1 formula (In the formula, R represents hydrogen or formyl, X represents cyano or lower carbalkoxy, and Y represents hydrogen or nitro.) A thiophene-based compound represented by the following. 2 A compound represented by the formula HSCH ₂ COOR ₁ (2) (wherein R ₁ represents lower alkyl) and a compound represented by the formula NCCH ₂ X (3) (wherein X represents cyano or COOR ₁ and R ₁ is the same as above) (meaning the same thing) is condensed and ring-closed to form the formula (In the formula, X means the same as above.) A compound represented by the formula (R ₂ ) ₂ NCHO (5) (wherein, R ₂ represents lower alkyl) was obtained. By reacting phosphorus oxychloride in dialkylformamide, (In the formula, R ₂ represents lower alkyl, and X means the same as above.) It is characterized by obtaining a compound represented by the following formula, and then hydrolyzing or nitrating this compound and then hydrolyzing it. formula (In the formula, R represents hydrogen or formyl, and X and Y have the same meanings as above.) A method for producing a thiophene compound represented by the following. 3 formulas (In the formula, X represents cyano or COOR ₁ , R ₁ represents lower alkyl) A compound represented by the formula (R ₂ ) ₂ NCHO (5) (wherein, R ₂ represents lower alkyl) By reacting phosphorus oxychloride in dialkylformamide, (wherein X and R ₂ have the same meanings as above) is obtained, and then this compound is hydrolyzed or nitrated and then hydrolyzed. A method for producing a thiophene compound represented by the formula (wherein R, X and Y have the same meanings as above).