DE1643246C3 - 2,5-Di- (methylmercapto) -4-chlorophenol and process for the preparation of 2,5-Di- (alkylmercapto) -4-chlorophenols - Google Patents

Description

(II)

-SR

(I)

ίο in which R has the above meaning, is reacted with methanolic alkali at temperatures of 190-250 ° C in an autoclave and from deui acidified reaction mixture, the 2,5-di- {alkyhnercapto> 4-chIor-

in which R is an alkyl radical with 1 to 16 carbon phenol and the 2,5-di-

atoms means, d ad u r c h g e k e η η ze i c h - 15 chloro- ^ alkyl mercaptophenol of the general forms!

net that one is a l ^ DHalkylmercaptoJ ^ S-dichloro-benzene the general formula

RS

(ID

OH

in which R has the above meaning, reacts with methanolic alkali at temperatures between 190 to 250 ⁰ C in the autoclave and from the acidified reaction mixture the 2,5-di- (aIkylmercapto) -4-chlorophenol and the 2,5- Dichloro-4-alkyl mercaptophenol of the general formula

wins.

"The compounds of the formula Ϊ arise (as

Sodium salts) according to the reaction scheme

Cl

RS

SR + 2NaOK

Cl

Cl

35

(III)

Methanol,

OH

- / "V-SR + NaCl

Cl

wins
2. 2,5-Di (methyl mercapto) -4-chlorophenol.

40 Cl

+ CH ₃ OCH ₃

the formation of the dimethyl ether shows that the reaction proceeds via the corresponding anisole. One Side reaction leads according to the reaction scheme

45

Phenol derivatives which contain two alkyl mercapto groups in addition to a chlorine atom in the nucleus not yet known. Also according to the method of German Patent 1,063,177, under If an excess of sulfenyl chloride was used, a double suusutüiiori fiiCui could be achieved will.

The invention relates to 2,5-di- (methylmercapto) -4-chlorophenol and a process for the preparation of 2,5 - di - (alkylmercapto) - 4 - chlorophenols of general formula

/ Λ-SR + NaOCH,

RS- Cl Cl -OCH ₃ + RS - N / A Γ Λ _ Γ
CI

OH

-SR

(I)

0Na + R-S-CH ₃

65

in which R denotes an alkyl radical with 1 to 16 carbon atoms, which is characterized by the addition of the sodium salt of 2,5-dichloro-4-alkyl mercaptophenol. If R is CH ₃ , the by-product is 25% of theory.

I 64 * 246

From the sodium salts formed in the reaction the phenols are in a normal way Acidification released and isolated.

The 2,5-bi- {alkyIniercapto) -4-chorophenols thus prepared as well as the 2,5-dichloro-4-alkyl mercaptophenols have bactericidal and fungicidal properties. They are still valuable intermediates for the production of insecticides.

The starting materials of the formula II can be produced by 1,2,4,5-tetrachlorobenzene with the double the molar amount of sodium alkyl mercaptide at elevated temperature

example

15th

A mixture of 359.0 g (1.5 mol) 1,4-di- (methylmercapto) -2 _i 5-dicbJorbeiizoi, IQOQ with methanol and 132 g NaOR (98%, 3.25 mol) is 12 hours, bsi 200 ⁰ C in a 2-1-reacted SchütteIautoklav the Reaktionskjsung is then filtered, concentrated, and the residue is dissolved in water. It is filtered again and acidified with dilute sulfuric acid, the phenol is separated off, diluted with ethylene chloride and dried over sodium sulfate. The ethylene chloride is stripped off in vacuo.

A residue of 315 g of crude puenol is obtained. After the distillation, 280 g of the phenol with a boiling point of 0.2 112 to 130 ° C. (yield about 84.7%) are obtained. According to the nuclear magnetic resonance spectrum, this phenol consists of 31% 2 _> 5-di-chloro-4-methyl mercaptophenol and 69% of 2,5-di (methyl mercapio} -4-chloro-phenol. The two can use one column compounds are separated in a vacuum. from 280 g of crude phenol front Kp ^ _-2112 be up to 130 ⁰ C 180 g of 2,5-di-imethylmercapto) -4-chloro-phenol \ om Kp.0.2 127-130 ° C and 85 g 2,5-Di-chJer-4-methylraercapto-phenoi from bp ^ ₂ ! 12 to! 15 ° C.

The latter compound can be crystallized from gasoline, being the substance with a melting point from 111 to 112 ° C

The chlorine and sulfur analysis proved the constitution of the above compounds.

The erfindungsgemäSen from the 2,5-di-imethyimercapto) -A- chloro - phenol producible O ₅ O - diethyl - O - (4 - chloro - 2,5 - dimeihylmercaptophenyl} -thionophosphat (cf. the German Ofienlegungsschrift 1,643,664}. is a valuable insecticide, which is superior in its effect to comparable known compounds. This shows the following comparison of the effect against aphids (Aphis fabae):

O, O-diethyl-O- (4-chloro-2,5-dimethylmercaptophenyl) -thionophosphate

ED ₅₀ 1.7 ppm ED ₉₉ 9.4 ppm

Ο, Ο-dimethyl O- (4-methylmercaptp-3-methylphenyl) thionophosphate

ED ₃₀ 3.3 ppm ED ₉₉ > 20 ppm

Claims (1)

Patent claims: I. Process for the preparation of 2,5-di- (alkylmercapto) -4-chlorophenols of the general formula that one is a 1 ^ DHalkylmercaptoRS-dichlorobenzene the general formula Cl