DD213434A1 - PROCESS FOR PREPARING 1,2-DITHIOL COMPOUNDS - Google Patents

Abstract

The invention relates to a process for the preparation of 4-hydroxy-5-thio-1,2-dithiol-3-thiones and derivatives and 3,5-bis (alkylthio) -1,2-dithiolyl-4-olates, which as Valence isomers of Tetrathiomesoxalsaeure, their mono- or diester are to be considered. The aim of the invention is to develop a simple process for the preparation of these previously unknown compounds. According to the invention, the object is achieved in that haloacetones with different numbers and distribution of the halogen atoms in the molecule, but with at least two halogen atoms, in particular 1,3-dihalopropan-2-one, with elemental sulfur in the presence of bases or with polysulfides, advantageously in a solvent and at room temperature to give compounds of general formula I and II. The compounds are of interest for complex crop protection and semiconductor chemistry.

Description

Process for the preparation of 1,2-dithlo compounds

Field of application of the invention

The invention relates to a process for the preparation of 1,2-dithio compounds which are of interest for complex, crop protection and semiconductor chemistry.

Characteristic of the known technical solutions

Although the 1,2-dithiols have long been known and heavily processed compound types, those with the substituent pattern shown below have not been previously described. See, for example, the review in Sulfur Reports by C.Ki.Pederson, Vol. 1 (1980) ), 1-96 (ed. S.Singing) and literature cited here. As compounds with similar chemical structure, only: 4-hydrosyl-5-phenyl-1,2-dithiol-3-thione, 3-alkylthio-5-phenyl »·, 3, 5-diaryl-, 3, 5- Di-tert-butyl and 3-tert, 3-butyl-5-aryl-1,2-dithiolyl-4-olates, which are completely different in several ways. very elaborate reaction stages were obtained from special starting compounds.

Tetrathiomesoxalic acid, its mono- and diesters or their valence-isomeric compounds were previously unknown. "Attempts to synthesize them remained unsuccessful.

31.JAM933 * O6577O

Object of the invention

it is a simple process for the preparation of the 4-hydroxy-5-mercapto-1, 2-dithiol-3-thione and derivates thereof, such as 4-hydroxy-5-alkylthio-1,2-dithiol-3 thiones and 3? 5-disubstituted 3? 5-bimercapto-1,2-dithiolyl-4-Qls.te, which are to be regarded as cyclic valence isomers of tetrathiomesoxalic acid, its mono- or Bithioesters to develop.

" Explanation of the nature of the invention

The object of the invention is to synthesize these hitherto not described Yerbindungstypen and to investigate their structure and reactivity.

According to the invention the object is achieved in that haloacetones with different numbers and distribution of the halogen atoms in the molecule, gedoch with at least 2 halogen atoms. For example, T, 3-Bihalogenpropan-2-one, with elemental sulfur in the presence of bases or with polysulfides, advantageously in a solvent or mixture, at about Eauiatemperatur reacted. As a solvent, for example, ¹ BMF, DIBO, Alka- J sole, v / water, hydrocarbons or mixtures thereof, as bases tertiary amines, alkali metal or alkaline earth metal oxides, hydroxides or alkanolates can be used. Bas to Setrathiomesoxalsäure valenzisomere, tautomerically stabilized 4-Hydr © xy-5-mereapto-1,2-dithiol-3-thione can be prepared by diluting the Sea & tion mixture with water and acidifying with dilute aqueous mineral acids to ca * pH 2 and subsequent extraction with eg Halogenated, hydrocarbons or as ammonium salt after addition of gaseous or aqueous HH- from its solutions of organic solvents, such as acetone or

Halogenated hydrocarbons] !, win. For the preparation of the mono- and dialkyl derivatives, suitable alkylating agents are alkyl, aralkyl halides, which may optionally contain further functional groups, or also dialkyl sulfates or sulfonic acid alkyl esters. The alkylation takes place in the reaction mixture or after extraction of the reaction product and with the addition of a base. Depending on the type and amount of the alkylating agent and the added base, 4-hydroxy-5-alkylthio-1,2-dithiol-3-thiones or mesoionic 3,5-bis (alkylthio) -1,2-dithiolylium-4- are formed. olate.

The 3,5-bis (alkylthio) -1,2-dithiolyl-4-olates can be'Basenzusatz, advantageously by alkali sulfides or hydrosulfides, in 4-hydroxy-5-alkylthio-1,2-dithiol-3-thiones convict.

embodiments example 1

3,5-bis (methylthio) -1,2-dithioiylium-4-olate

7.4 δ 1,3-dichloropropane-2-one, 11.5 g of sulfur powder, 36.8 g of triethylamine are reacted in TOO ml of DMP at -16 to ^{0 0} C. Thereafter, the reaction mixture with water, CH ₂ Cl ₂ and dilute mineral acid is added, laughing after separation of the CH ₂ C1 ₂ phase and 2 to 3 ^ acher extraction of the aqueous phase with CHpCl ₂ , the combined CH ₂ Cl ₂ extracts over MgSO. dried and reacted after separation of the drying agent with 12.4 g of triethylamine and excess CH-I. The precipitate, which precipitates after a relatively long time and whose formation can be completed by cooling, is filtered off with suction and washed with water. To remove possibly precipitated sulfur can

be treated with CSp. This gives 9.5 g of substance. Schinp. from GH ₃ OHrHo-HS ⁰ G (decomposition). From the CHgClg filtrate 4-Hydro2j-5-niethylthio-1,2-dithiol-3-thione can be obtained.

Example 2

4-Hydro3: y-5-methylth.io-1,2-dithiol-3-thione

7} 4 S 1 "3-dichloropropan-2-one are reacted as above. To the G ^ Clg extracts are added 6.1 g of triethylamine and H, 0 g of GHoI. After completion of the reaction, the solution is concentrated to half the volume, separated by cooling possibly formed 3,5-BisCmethylthio) -1,2-dithiolium-4-olate and then completely removed the solvent. The further purification of the dark residue is carried out by recrystallization or redissolution from ethanol; dark crystals of the Mp. H0-H5 ° G. Analogously to Example 1 baw. Example 2, the following compounds were obtained:

3,5-bis (ethylthio) -1,2-dithiolium-4-olate 5-ethylthio-4-hydroxy-1,2-dithiol-3-thione 5- (2 ', 4-dinitrophenylthio) -4 ~ hydroxy 1,2-dithiol ~ 3-thione

Example 3

4-hydroxy-5-methylthio-1,2-dithiol-3-thione

3,5-bis (meth5-ithio) -1,2-dithiolium-4-olate is dissolved in aqueous ITapS solution at room temperature, after brief stirring (5 min.) With dilute mineral acid adjusted to about pH 8-9 and extracted with CH ₂ Gl ₂ . After removal of the solvent, the dithiolthione is obtained in almost quantitative yield.

Example 4

-1,2-dithiol-3-thione-5-ammoniumthiolat

is introduced by passing gaseous UIL into the extraction solution obtained after working up of the reaction mixture of: - hydroxy-S-mercapto-i, 2-dithiolthione (see Example 1) or by adding an acetone solution with aqueous 1H, as a red to brown yield obtained approx., 805 δ calculated on dihaloacetone.

Example 5

4-hydroxy-5-methylthio-1,2-dithiol-3-thione

The above ammonium salt is dissolved in ClLOH with the addition of catalytic amounts of triethylamine and treated at excess temperature with excess CHoI, lach a short reaction time is acidified with highly dilute, aqueous HCl. The forming light brown precipitate is sucked off. M.p. 140-145 ⁰ C.

Example 6

3,5-bis (methylthio) -1,2-dithiolylium-4-olate

The ammonium salt is dissolved in methanol with the addition of equimolar or double molar amounts of triethylamine and mixed with excess CH-I. After a short reaction time, the solvent is removed and the residue is recrystallized from water. 70% yield.

Claims (3)

1. A process for the preparation of 1,2-dithiol compounds, characterized in that haloacetones with different numbers and distribution of the halogen atoms in the molecule, but with at least two halogen atoms, with elemental sulfur in the presence of bases or with polysulfides, advantageously in a solvent, at temperatures from -50 ° to 25O ⁰ C, in particular at 0 ° to 30 ⁰ C, with or without subsequent alkylation, to give compounds of general formula I and II implemented - OH (Γ R ¹ S 1 SR ² S 1 ! S-S S-S II 1 2 "3 wherein R = H, alkyl or aralkyl and R, R ^ = alkyl or aralkyl which are identical or different and optionally contain functional groups. 2. Method according to. Point% characterized in that the compounds of the general Pormel I and II (R, RR £ H) by alkylation in the reaction mixture, after extraction of the reaction product in solution or after pure isolation of I (R = H) or in the form of its salt, with or without the addition of bases. 3. Method according to. Item 1, characterized in that the compounds of the general formula I and II are to be regarded as valence isomers of tetrathiomesoxalic acid, its mono- and diesters and at least partly, e.g. in solvents, as such.