SU543350A3 - The method of producing thiazolsulfenamides - Google Patents

Description

(54) METHOD FOR OBTAINING TIAZULSULFENAMIDES

This invention relates to a process for the preparation of thiazole sulfenamides, in particular benzothiazole sulfenamides obp1, of formula I. K. 11 11 g -S-tmg CSN R, -CS, which are important industrial products used as rubber vulcanization accelerators, where RI and R2 together form a bivalent radical of general formula II where RR, R and the same or different means hydrogen, halogen, nitro, alkyl or alkyloxy radical with 1-5 carbon atoms, aryl radical with 6-12 carbon atoms, and Rs and R4 identical or different, mean hydrogen, alkylene radical, linear or branched with 1-20 carbon atoms, cycloalkyl radical with 5-12 carbon atoms, arylalkyl radical with 7-15 carbon atoms, or together with the nitrogen atom with which they are bound, form a heterocycle containing 5-7 chain units and optionally 1 -2 heteroatoms of nitrogen, oxygen, sulfur, and oxygen, substituted or unsubstituted with alkyl or alkyloxy groups of 1-5 carbon atoms. A known method for the preparation of thiazolsulfenamides and the oxidative condensation of mercaptothiazoles or their disulfides with primary or secondary amines in an aqueous or organic medium, preferably in the presence of an oxidizing agent, such as alkali metal hydrohalides, such as sodium hypochlorite. This method leads to a good yield of thiazole sulfenamides, but it has the disadvantage of consuming a significant amount of expensive oxidizing agents. There is also known a method for producing thiazolsulfenamides of general formula I by reacting dithiazolyl-2,2-disulfide of general formula III

V,

(Ш1

S-C-R.

or 2-mercaptobenzothiazole with a nitrogen-containing compound of the general formula IV

TO:;

where Rb R2, Rs and R4 are as defined above, at 25-100 ° C in the presence of oxygen or air and a metal phthalocyanine, preferably containing a hydrophilic group, for example a sulfonate group as a catalyst.

Cobalt phthalocmanines are preferably used, although metal phthalocyanines, such as manganese, vanadium, chromium, nickel, iron and copper, can also be mentioned. Metallic phthalocyanines, in particular copper sulfated phthalocyanines, are not widely available and difficult to obtain, which generally reduces the efficiency of the process.

In order to increase the efficiency of the process, it is proposed to use the copper salt of a lower aliphatic carboxylic acid as a catalyst.

In formulas I and II, Ri, Rs, Ri, R, R, and Riv means, in particular, chlorine or bromine, an alkyl radical such as methyl, ethyl, propyl, isopropyl, butyl, Guoeg-butyl, pentyl, methyloxyl, ethyl oxyl , propyloxyl, butyloxy, toluyl, ethylphenyl, nitrophenyl, chlorophenyl, naphthyl; Rs and R4 mean methyl, ethyl, propyl, isopropyl, butyl, its / 5-butyl, treg-butyl, npeptil, isopentyl, hexyl, heptyl, w-octyl, decyl; cyclopentyl, cyclohexyl-2-methylcyclohexyl, cycloheptyl, cyclooctyl, cyclododecyl; benzyl, p-phenylethyl, or together with the nitrogen atom to which they are bonded, form pineridyl-, morpholyl-, pyrrolidyl-alkylpiperazyl, 3,5-dimethylmorpholyl-, 2,6-dimethylmorpholyl-, 2-methyl-5-ethylpiperidyl -, hexahydroazepinylcycle.

Of the nitrogen-containing derivatives corresponding to formula III, ammonia, primary amines such as methylamine, ethylamine, n-propylamine, isopropylamine, α-βB3Tylamine, b-butylamine, t-butylamine, n-pentylamine, n-hexylamine, tert-pentilamine, n-hexylamine, can be used. , heat-octylamine, noktilamin, cyclopentylamine, cyclohexylamine, 2-methylcyclohexylamine, (cyclopentylmethyl) amine, benzylamine, a-methylbenzylamine, secondary amines such as dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, dibutylamine, di-Treg-butylamine , din-pentylamine , dpizopentylamine, dicyclohexylamine, ethylcyclohexylamine, methyl - "- butylamine, methylbenzylamine; heterocyclic bases such as cyceridine, morpholine, pyrrolidine, dimethyl-2,6-morpholine, 3,5-dimethylmorpholine, hexahydroazepine, MOHo-N-methylpiperazine, N-ethylpiperazine, thiomorpholine, 2 methyl-5-ethylpiperapi, 2-methylpiperazine

Although metallic copper provides the normal oxidative condensation of dithiazolyl disulfide and amines or ammonia, it is preferable to use its derivatives. It is preferable to choose a compound that is soluble in the reaction medium used, which may be an aqueous, organic or aqueous organic medium.

As examples of copper salts of lower aliphatic carboxylic acids used according to the proposed method, formic, acetic, chloroacetic, dichloroacetic, propionic, butyric, caproic, valeric, adipic, tartaric, cyclohexanecarboxylic acid can be mentioned.

As separate examples of copper salts of carboxylic acids, monovalent and divalent copper acetates can be mentioned.

Sy SNSOO; C SNZSOO 2-H20;

bivalent copper formate; basic copper acetates

2Ci CH2SOO 2, Cu (OH) 2-5H2O; Cu CH3 2, Cu (OH) 2-5H2O; Si CH3SOO 2, 2Ci (OH) 2; Si CH3SOO 2-ZCi (OH) 2;

basic copper formates

 ZSi (OH) 2; ,

2Ci (OH) 2.

The molar ratio of ammonia or amine to dithiazolyl-2,2-disulfide can be varied within very wide limits depending on the reaction conditions. If this reaction is carried out in water or in an organic solvent, stoichiometric quantities of reagents can be used; then molar

the ratio is 2, although it is preferred to use an excess of the nitrogen-containing compound, which may be 0.5 to 5 times more stoichiometric amounts. It is even more advantageous to use amines as the reaction solvent.

The organic solvents include aliphatic alcohols - methanol, ethanol, propanol, treg-butanol; amides-dimethylacetamide, acetonitrile, complex

methyl acetate and ethyl acetate; tertiary amines — trimethylamine, triethylamine; tertiary heterocyclic bases — pyridine; aromatic hydrocarbons - benzene, toluene.

The amount of copper used, expressed as the ratio of the number of atoms of copper to the number of moles of dithiazolyl-2,2-disulfide, can be varied over very wide limits. More precisely, this ratio may be 0.0001 -

0.5 and preferably 0.001-0.1.

The process is carried out at O-200 ° C, preferably at 20-150 ° C, the partial pressure of oxygen can be varied from 0.1 to 30 atm.

The practical implementation of the proposed method is very simple; it is sufficient to contact the liquid reagents containing the catalyst with oxygen or a gas containing it according to the methods commonly used to ensure that reactions take place between the liquid and gaseous phases. When the reaction is complete, sulfenamide is isolated by conventional means.

Example. A 200 cm glass reactor, equipped with a double scrub for circulating heating fluid, a thermometer, a reflux condenser and a stirring system, is charged with 37 cm of cyclohexylamine (0.288 mol), 5.25 g of dibenzothiazolyl-2, 2-disulfide (0.015 mol) and 0.205 g of cupric acetate. The temperature is raised to 50 ° C, held for 25 minutes under these conditions, then the contents of the reactor are cooled to 20 ° C and filled with nitrogen. 190 cm of oxygen (0.007 mol) is generally absorbed. The excess cyclohexylamine is determined by IN H 2 SO 4 (it is 0.266 mol). Distilled water is added to the reaction mass and transferred for 20 minutes at 20 ° C. A precipitate is obtained, which is separated by filtration, washed on the filter with 2 times 20 cm of water, dried in a drying cabinet to a constant weight. So get 6,17 g of the product is white with so pl. 102-103 ° C, in which 91.5% of N-cyclohexylbenzothiazole sulfenamide is measured (after the sample is dissolved in a toluene / isocropanol 40% / 60% by volume, decomposition of H2S and determining the free amine by acidometry). The yield of sulfenamide with respect to the disulfide recovered is 71.5%.

where RI and R2 are the same or different, together form a bivalent radical of general, formula II

Ul

IV where R R, R ™ and R are identical or different, means hydrogen, halogen, nitro, alkyl or alkyloxy radical with 1-5 carbon atoms, aryl radical with 6-12 carbon atoms; Rs and R4 are the same or different, mean hydrogen, an alkyl radical, linear or branched with 1-20 carbon atoms, a cycloalkyl radical with 5-12 carbon atoms, arylalkyl radical with 7-15 carbon atoms, or together with the nitrogen atom with which they are linked, form a heterocycle containing 5-7 chain links, possibly an additional 1-2 heteroatoms from the group of oxygen, nitrogen or sulfur, substituted or unsubstituted by alkyl or alkyloxy groups with 1-5 carbon atoms, by reacting dithiazolyl-2,2 -disulfide of general formula III

„G- (III) V city / 5 -t - Kj

  .

With a nitrogen-containing compound of the general formula IV

./RS

NiK: / uvi

Claims (1)

M, Formula of the invention. A method for the preparation of thiazole sulfenamides of the general formula I T1, -CN 3 (: - sN: (J). J50 where RI, Rs, Rs and R4 are as defined above, at elevated temperatures in the presence of oxygen or oxygen-containing gas and a copper based catalyst, characterized in that, in order to increase the efficiency of the process, a copper salt of lower aliphatic carboxylic acid is used as a catalyst.