DD251130A1 - PROCESS FOR THE PREPARATION OF 4 AND 5 POSITION SUBSTITUTED DERIVATIVES OF 1,3-DITHIOL-2-THIONE - Google Patents

Abstract

The invention relates to a novel improved process for the preparation of derivatives of 1,3-dithiol-2-thiones having substituents in the positions 4 and 5 of the general formula I, in which R1 is an alkyloxycarbonyl, nitrile, acetyl, benzoyl or substituted benzoyl group and R2 is an alkyl, benzyl, subst. Benzyl-alkoxycarbonylmethyl, cyanomethyl, phenacyl, subst. Phenacyl group or acetylmethyl group. According to the invention are O-alkyl-S- (acceptoromethyl) -dithiokohlensaeureester, wherein the acceptor corresponds to the radicals R1 of the general formula and an alkoxycarbonyl, nitrile, acetyl, benzoyl or substituted benzoyl group, with carbon disulfide in the two-phase system chloroform or a similar water-immiscible organic solvent / aqueous alkali metal hydroxide solution in the presence of a compound used in phase transfer catalysis, such as. B. Benzyltriethylammoniumhalogenid or hydrogen sulfate, and the resulting 1,3-dithiol-2-thione-4-thiolate with alkylating agents R2X, wherein XChlor, bromine, iodine and R2 alkyl, benzyl, subst. Benzyl, alkoxycarbonylmethyl, cyanomethyl, phenacyl, subst. Phenacyl or acetylmethyl group, is reacted. The 1,3-dithiol-2-thiones serve as synthesis building blocks for the preparation of organic metals, pesticidal compounds and antioxidants of various fields of application.

Description

Explanation of the essence of the invention

The invention is based on the object of finding a new single-stage chemical process for the preparation of 1,3-dithiol-2-thiones. According to the present invention, in a two-phase reaction, they are reacted in chloroform or a similar water-immiscible organic solvent and aqueous alkali hydroxide solution in the presence of a compound used in the phase transfer catalysis such as benzyltriethylammonium halide or hydrogensulfate, O-alkyl-S-acceptoromethyldithiocarbonic acid ester and carbon disulfide. In this reaction, the resulting after carbon disulfide addition to the carbanion formed intermediate cyclized to form the Benzyltriethylammoniumsalzes of 1,3-dithiol-2-thione-4-thiolates, with a variety of alkylating agents R ² X (X = chlorine, bromine, iodine) to the compounds I is implemented. In this case, a reaction process occurs, which was completely surprising. According to the known reaction of / 3-keto esters and nitriles with carbon disulfide under the conditions of the phase transfer reaction to salts of corresponding dithiocarboxylic acids whose alkylation under basic conditions leads to keten-SS-acetals (L JENSEN, L DALGAARD, S.-O. LAWESSON: Tetrah., 30, 2413 [1974]), it was thought that ketene-SS-acetals having the acceptor group R ¹ and the alkoxythiocarbonylthio group were obtained. According to the invention, these substituted 1,3-dithiol-2-thiones of general formula I are prepared by reacting O-alkyl-S- (2-oxo-propyl) -, O-alkyl-S- (phenacyl) -, O-alkyl -S- (cyanomethyl) - or O-alkyl-S- (alkoxycarbonylmethyl) -dithiocarbonic acid esters readily available from potassium alkyl xanthogenates and 2-haloacetic acid derivatives, bromoacetone or phenacyl halides at room temperature dissolved in carbon disulfide to a mixture of chloroform or a similar to water miscible organic solvent / water / alkali hydroxide / benzyl triethyl-ammonium salt are added dropwise with vigorous stirring and 15 minutes later, the alkylating agent R ² X, wherein R ^{2 has} the same meaning as in the general formula I is added. After 1 hour of vigorous stirring, the organic phase is separated and the product is isolated by concentration of this solution. For purification, it is recrystallised, for example from the solvents listed in the tables.

The process according to the invention illustrates equation 1. Tables 1 and 2 give examples of compounds prepared by the process according to the invention.

General formula I:

RS ^N S equation 1:

Alkali hydroxide solution ΤΞΒΑ halide or

H .0-CS-SOLR ¹ + CS ₀ Hydrogen sulfate II

TEBA

R ² X

R.

 s

S ^XX S

Table 1

R ¹ .S

Verb.

Mp [ ⁰ C]

Y. [%]

CO ₂ C ₂ H ₅

CN

COCH ₃

COC ₆ H ₅

COC ₆ H ₄ -P-CI

COC ₆ H ₄ -P-Br

130-31 (acetonitrile) 118-119.5 (methanol) 165-166 (acetonitrile) 142.5-143.5 (acetonitrile) 164.5-166 (n-butanol) 182-183 (n-butanol)

72 65 69 58 65 70

Table 2

CH CO

Verb.

Mp [ ⁰ C]

Y. [%]

C ₂ H ₅ 93-94 (ethanol) 59 CH ₂ CO ₂ CH ₃ 97-97.5 (n-butanol) 63 CH ₂ COC ₆ H ₅ 156-158.5 (n-butanol) 80 CH ₂ COC ₆ H ₄ -P-CI 147.148.5 (n-butanol) 76 CH ₂ COC ₆ H ₄ -P-Br 177-178.5 (n-butanol) 78 CH ₂ C ₆ H ₅ 113-114 (ethanol) 64 CH ₂ COCH ₃ 190-191 (n-butanol) 67

embodiments Example 1:

ö-ethoxycarbonyl ^ methylthio-i ^ ^ dithiol -thione

10.4 g (0.05 mol) of ethylxanthogeneacetic acid ethyl ester are dissolved in 50 ml of carbon disulfide and added to 19.2 g (0.1 mol) of triethylbenzylammonium bromide, 11.2 g (0.2 mol) of potassium hydroxide in 100 ml of water and 100 ml of chloroform. After stirring at room temperature for 15 min, 7.92 g (0.055 mol) of methyl iodide are added dropwise while cooling with ice, and the mixture is stirred at room temperature for 1 h. Thereafter, the layers are separated and the organic phase is dried over sodium sulfate and evaporated down iV. This gives 9.1 g of yellow needles (with acetonitrile / A-carbon purified) of melting point 130-131 ⁰ C.

Example 2:

ö-acetyl-phenacylthio-i, 3-dithiol-2-thione

8.9 y (0.05 mol) Ethylxanthogenaceton be implemented in the above procedure. The alkylating agent used is 10.9 g (0.055 mol) of phenacyl bromide. This gives 12.9 g of yellow needles (recrystallized with n-butanol / charcoal) of melting point 156-158.5 ° C.

Claims (1)

A process for the preparation of 4-substituted and 5-substituted 1,3-dithiol-2-thionen of the general formula I in which R ^{1 is} an alkyloxycarbonyl, nitrile, acetyl, benzoyl or substituted benzoyl group and R ^{2 is} an alkyl , Benzyl, subst. Benzyl, alkoxycarbonylmethyl, cyanomethyl, phenacyl, subst. Phenacyl or acetylmethyl group, from O-alkyl-S- (acceptoromethyl) -dithiokohlensäureestern, wherein the acceptor groups the radicals R ^{1 of} the general formula I correspond to carbon disulfide, characterized in that in the two-phase system chloroform or a similar water-immiscible organic Solvent / aqueous alkali hydroxide solution and in the presence of compounds used in the phase transfer catalysis, such as. B. Benzyltriethylammoniumhalogenid or hydrogen sulfate, are reacted and the resulting thiolate anions with a halogeno compound R ² X (X = Cl, Br, I), in which R ^{2 has} the same meaning as in the general formula I alkylated. For this 1 page formulas Field of application of the invention The invention relates to a novel improved process for the preparation of derivatives of the 1,3-dithiol-2-thiones of the general formula I in which R ^{1 is} an alkyloxycarbonyl, nitrile, acetyl, benzoyl or substituted benzoyl group and R ^{2 is} an alkyl , Benzyl, subst. Benzyl, alkoxycarbonylmethyl, cyanomethyl, phenacyl, subst. Phenacyl group or acetylmethyl group. The production process according to the invention makes available intermediate products which can be used for the preparation of tetrathiafulvalenes. The process according to the invention can be used in organic intermediate chemistry for the production of organic metals, pesticidal compounds and antioxidants in a wide variety of applications. Characteristic of the known technical solutions The preparation of the 1,3-dithiol-2-thiones, which contain functional groups in the 4- and 5-position, is achieved by a number of methods. The reduction of carbon disulfide by various procedures yields the dianions of 4,5-dithiol-1,3-dithiol-2-thiones, which can be alkylated or acylated in various ways (I. KÖSTER and K. HARTKE: Arch. Pharm. [Weinheim] 317, 995-1002 [1984]). Another synthesis is based on carbon disulfide iron complexes, which with activated acetylene compounds such. B. acetylenedicarboxylic be implemented. These addition compounds can be converted to the 4,5-disubstituted 1,3-dithiol-2-thiones with sulfur (M. NGOUNA, H. LE BOZEC, P. DIXNEUF: J. Org. Chem.47.4000 [1982]) , The yields of this synthesis are not very high. Further, the photochemical reaction of phenylacetylenes with ethylenedithiocarbonate results in poor yields of phenyl-substituted 1,3-dithiol-2-thiones (S. YAMADA, N. MINO, N. NAKAYAMA, M.OHASHI: J. Chem. Soc. Perkin Trans. 11984 2497). In addition, the photolytic reaction of 1,2,3-thiadiazoles in carbon disulfide also provides compounds of the 1,3-dithiol type (R. HUISGEN, V. WEBERNDÖRFER: Experentia 17,566 [1961]). A further method consists of reacting O-alkyl-S-acceptoromethyldithiocarbonic acid esters with carbon disulfide in a dipolar aprotic medium in the presence of a base, the title compounds being obtained in reasonable yields after alkylation (M-AUGUSTIN ₁ W-DoLLING: DD 208152 [1984] ). Derivatives of the 1,3-dithiol-2-thione, which carry a donor substituent in the 5-position in the 4-position in the form of the alkylthio group, can be obtained for the first time using this method. However, this method has the disadvantages that one must work with anhydrous solvents, with tertiary alcoholates or sodium hydride as bases and under inert gas (nitrogen). Object of the invention The aim of the invention is to produce the derivatives of 1,3-dithiol-2-thiones from readily available, cheaper starting materials while saving process steps with improved yields and in a simple manner.