DD216937A1 - PROCESS FOR PREPARING 4,5-DITHIOSUBSTITUTED 2-ARYL-THIAZOLENE - Google Patents

Abstract

The invention relates to a process for the preparation of 4,5-dithio-substituted 2-aryl-thiazoles obtained by reacting dialkali salts of 2-aryl-4,5-dimercaptothiazoles with alkyl, aralkyl or benzoyl halides, 1, 2-Dihalogenethanen or Benzoylhalogeniden be obtained. The aim of the invention is to find a preparatively simple synthesis process for the title compounds, which have significance as intermediates for subsequent syntheses.

Description

VEB CHEMIEKOMBlJSAT BITTBRi ¹ EID Bitterfeld, June 29, 1983

2379. ;

Process for the preparation of 4,5-dithio-substituted-2-aryl-thiazoles

'

Field of application of the invention

The invention relates to a process for the preparation of novel 4,5-dithio-substituted-2-aryl-th.iazoles. S ¹ Ur thiazoles has been known for a variety of applications. Numerous pharmaceuticals, PSM drugs and intermediates for organic syntheses have been described,

Characteristic of the known technical solutions

By reaction of Na cyanodithioformiat with carbonyl compounds in the presence of a secondary amine Jtfatriumsalze of Mercaptothiazolderivaten have become easily representable · Thus , upon reaction of Na-cyanodithioformiat with ketones, the sodium salts of 4 ~ mercapto-5-oxo-thiazolines, in reaction with benzaldehydes but the Disodium salts of 2-aryl-4,5-dimercaptothiazoles. In the 4- and 5-position thiosubstituted thiazoles have not been described.

- * MK'l'.tl

ίΧί-lL f

- 2 - /. 2379 goal of Erfindu ng

The aim of the invention is to find a simple process for the preparation of the title compounds from readily available starting materials in a preparatively uncomplicated, easy to implement manner.

< Presentation of the essence of the invention

; The invention relates to a novel process for the manufacture; mentation of di-4,5-substituted i-2-aryl-thiazoles of the general formula

in which B is an aromatic radical which may optionally be substituted by lower alkyl or alkoxy groups or halogen atoms, and when ν is O and u and w are 1, Q represents nitro- or halogen-substituted aralkyl or benzoyl radicals and when w is O and u and ν is 1, Q is a methylene group and E ^{1 is} hydrogen and when u and w are the same and ν is 1, H * is a substituted phenyl radical

The ^^ - dithiosubstituted ^ aryl-thiazoles of the general formula ## STR1 ## are obtained by reacting the corresponding dialkali salts of 2-aryl-4-, 5-dimercaptothiazoles with equimolar amounts of alkyl, aralkyl or benzoyl halides, 1,2-dihalogenethanes and benzal halides in lower alcohols or ethers at temperatures between Eaumtemperatur and the boiling point of the used

r - 3 - 2379

Solvent produced.

The 4,5-dithio-substituted 2-aryl-thiazoles of the general formula are obtained in good to very good yields as yellow, crystalline substances.

! The advantage of J = Tf indung is that 4,5-dithio-; substituted 2-aryl-thiazoles of the general formula can be prepared in a preparatively simple manner by using the readily available dialkyl salts of 2-aryl-4,5-dimercaptothiazoles (cyclization products of the Qyanoditiiioformiate with aldehydes). _/

Execution example

The invention will be explained in more detail with reference to the following examples and the data of the table, without being limited thereto.

  ''

example 1

["' , * '

0.01 mol of the corresponding disodium salt of a 2-aryl-4,5-dimercaptothiazole is dissolved in 100 ml of anhydrous MeOH.

Taken up and added with 0.02 mol of 4-nitro-benzyl bromide. The dibenzylated reaction products begin to precipitate after only a short time and finally become acid after standing for five hours

 * · - * Room temperature filtered off and purified by recrystallization from Ghloroform / n-hexane mixtures with the addition of activated charcoal. -

Example 2 ".

0.01 mmol of the disodium salt of 4,5-dimercapto-2-r (4-methylthoxy-phenyl) -thiazole is suspended in 50 ml of anhydrous diethyl ether. To this is added dropwise 0.02 mol of 4-chlorobenzoyl chloride in 10 ml of diethyl ether while stirring * After the addition, stirring is continued for a further three hours at room temperature.

- 4 - 2379

diluted with 50 ml of chloroform and filtered off from sodium chloride. The filtrate is concentrated to 15 ml and the crystallized crude product filtered off. The reaction product is purified by recrystallization from chloroform.

Example 3

0.01 mol of the disodium salt of 4,5-dimercapto-2- (4-methoxyphenyl) -thiazole is largely dissolved in 50 ml of anhydrous ethanol and treated with 0.01 mol of 4-nitrobenzal bromide. The reaction mixture is heated for 10 minutes under reflux conditions and then allowed to stand for a further 5 hours at room temperature to crystallize the crude product. The precipitated reaction product is filtered off, washed with water and recrystallized from chloroform / n-hexane with the addition of activated charcoal

'.' · '. : ' Example 4

0.01 mol of the disodium salt of 4,5-dimercapto-2- (4-methoxyphenyl) thiazole is shaken together with 0.01 mol of 1,2-dibromomethane in 20 ml of anhydrous methanol for 30 minutes. After three hours of standing of the reaction mixture at room temperature, the precipitated crude product is filtered off, washed with water and recrystallized from methanol / chloroform ·

uvw exploit

(R ¹ )

( ⁰ )

Thode

10 1 65 1 Ο 1 75

144-145 136-138

4-WO ₂ -C ₆ H ₄ CH ₂ 10 1 80 164-165 1

4-Cl-C ₆ H ₄ 4-NO ₂ -O ₆ H ₄ OH ₂ 10 1 40 137-139 1

4-01-C ₆ H ₄ -CO 10 1 75 184-190 2

0 10 70

160

4-CH ₃ OC ₆ H ₄ CH ₂

(H)

1 1 0 45

97

Claims (2)

- 6 - 2379 '. '.' '*' ''. '' 3ärf claim 1. A process for the preparation of 4-, 5-dithio-substituted 2-aryl-thiazoles of the general formula : (CHR ») _V ^s "- S CQ) _W wherein H is an aromatic moiety which may be optionally substituted by lower alkyl or alkoxy groups or halogen atoms; if ν s O and u = w = 1, Q represents a nitro- or halogen-substituted aralkyl or benzoyl radical; if w β O and u = τ = 1, - '' Q represents a methylene group and Fi ^{1 represents} a hydrogen atom; if u s w '= 0 and ν »1, K ^{1 represents} a nitro-substituted phenyl radical; characterized in that dialkali salts of 2-aryl-4,5-dietherecapto-thiazoie, in which R has the above meaning - 7 - 2379 sitting, with equimolar amounts of alkyl, aralkyl or, benzoyl halides, 1,2-dihaloethane or benzal halides, which may optionally be ring-substituted, are reacted in lower alcohols or ethers at temperatures between room temperature and the boiling point of ein-r set solvent. 2 * Process according to item 1, characterized in that the corresponding sodium salts are used as alkali metal salts of 2-aryl-4,5-difflercaptothiazoles.