JPS649310B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing disulfides. More specifically, the present invention is a method for producing disulfides useful as aroma ingredients, dyes, medicines, various polymer additives, etc., which is characterized by reacting alkylthionitrites with mercaptans. Conventionally, asymmetric disulfides have been obtained by the reaction of symmetric disulfides, thiochlorides obtained from chlorine, and mercaptans, but this involves many steps, results in a mixture of symmetric disulfides and asymmetric disulfides, and is low in yield. , isolation was also virtually impossible. The present inventors have completed the present invention by discovering that by reacting alkylthionitrites with mercaptans, the desired disulfide, whether symmetrical or asymmetrical, can be easily obtained in extremely high yield. That is, the present invention provides a compound having the formula R ¹ --SNO [] [wherein R ¹ represents an alkyl group or an aralkyl group]. ] Thionitrites having the formula R ² —SH [ ] [wherein R ² represents an alkyl group or an aryl group]. ] Characterized by reacting with a mercaptan of the formula R ¹ -S-S-R ² [] (wherein R ¹ is R ¹ of the formula [], and R ² is R 2 of the formula [ ^] This is a method for producing disulfides. Although the reaction mechanism is not clear, mercaptans react with thionitrites as nucleophiles,
It is thought that disulfide is generated. In the above formulas [] and [], R ¹ is, for example,
Alkyl groups such as methyl, ethyl, butyl, t-butyl, hexyl, 2-ethylhexyl, dodecyl, benzyl, phenethyl, phenylpropyl,
Examples include aralkyl groups such as triphenylmethyl group. In addition, in the above formulas [] and [], as R ² ,
For example, methyl, ethyl, butyl, t-butyl,
Alkyl groups such as hexyl, 2-ethylhexyl, dodecyl, phenyl, naphthyl, anthranyl,
Examples include aryl groups such as biphenyl groups. The present invention can be easily implemented, for example, as follows. For example, if alkylthionitrite is required, it is dissolved or suspended in a solvent, kept at -30°C to 10°C, a theoretical amount of mercaptans is added, and the reaction is carried out for several seconds to several hours. After the reaction is completed, unreacted mercaptans are removed by washing with a dilute aqueous alkali solution, etc., and the desired disulfide is easily obtained by drying with magnesium sulfate, etc., and then distilling off the solvent if necessary. Obtainable. The starting material, alkylthionitrite, for example, if an alkylmercaptan is required, is dissolved or suspended in a solvent, kept at -30°C to 10°C, and a theoretical amount of N ₂ O ₄ is added to react for several seconds to 1 hour. It can be easily obtained if
Even if alkylthionitrites are isolated,
The reaction of the present invention may be carried out by directly adding mercaptans. Alkylthionitrites are very active compounds and are preferably treated at low temperatures and shielded from light. As the molecular weight of alkylthionitrite increases, its stability tends to increase; for example, n-dodecylthionitrite does not decompose for several weeks at room temperature. The solvent used if necessary in the present invention is usually an aprotic solvent, is liquid at the reaction temperature, and does not react with the starting material thionitrite. For example, a saturated solvent such as hexane or octane is preferably used. Hydrocarbons, aromatic hydrocarbons such as toluene and xylene, ethers such as diethyl ether, tetrahydrofuran, anisole, ethylene glycol diethyl ether and diethylene glycol dimethyl ether, ketones such as acetone, methyl isobutyl ketone and acetylacetone, ethyl acetoacetate, Esters such as ethyl acetate, nitriles such as acetonitrile and isobutyronitrile, halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, trichlorethylene, nitrogen-containing compounds such as dimethylformamide and nitromethane, carbon disulfide Examples include sulfur-containing compounds such as. These solvents may be used alone or in combination. That is, in the method of the present invention, various desired disulfides can be obtained very easily and quantitatively by selecting various alkylthionitrites and mercaptans and reacting them. Therefore, it is usually refined,
This is an innovative method that is particularly excellent as a method for producing asymmetric disulfides, and does not require any special operations such as isolation. As described above, the method of the present invention greatly contributes to this industry by extremely easily providing disulfides useful as aroma components, dyes, medicines, various polymeric additives, and the like. Reference examples and examples will be described below. Reference Example 1 A N ₂ O ₄ /carbon tetrachloride solution (20 mmo/2 ml) is added to 1.8 g of n-butyl mercaptan/20 ml of ether at -10°C under protection from light. The reaction solution immediately turns bright red. After washing with 5% cold sodium bicarbonate and drying with magnesium sulfate, under reduced pressure,
Trapped while shielding from light to obtain 2.36 g (yield 99%) of n-butylthionitrite. This product is used for liquid chromatography (filling material: polystyrene, column: φ2 mm, 46 cm, eluent: methanol, 150~
200Kg/cm ² ), it is a single substance. IR (CC ₄ ) ν = 1910, 1510, 1520, 770 cm ^-1 UV (CC ₄ ) λmax (ε) = 342 (780), 519 (13),
550nm (27) In addition, the IR characteristic absorption in the gas phase of methyl and ethylthionitrite, which are standard products for identification, is SN=
0; 1961, N=0; 1534, CS; 730 cm ^-1 . N ₂ O ₄ /CC ₄ solution was obtained by absorbing NO ₂ gas into cold carbon tetrachloride. The concentration was determined by titration with an aqueous solution of caustic soda. In the same manner, the alkylthionitrites shown in Table 1 are obtained.

[Table] Example 1 In the n-octylthionitrite carbon tetrachloride solution (2 mmo/20 ml) obtained in Reference Example 1, -
℃ ~ -5℃, protected from light, t-butyl mercaptan
Add 180 mg (2 mmo)/10 ml of carbon tetrachloride, stir for several minutes, and when the red color of n-octylthionitrite disappears, wash with 5% aqueous sodium bicarbonate solution, dry, and distill off the solvent to obtain n-octyl thionitrite. 384 mg (yield 82%) of t-butyl disulfide is obtained. This coincided with the peak of gas chromatography of separately synthesized n-octyl t-butyl disulfide (filling material: SE30, column φ2 mm 2 m, injection, detector 240°C, carrier gas N ₂ ). Disulfides shown in Table 1 were obtained in the same manner.

【table】

[Table] All of the disulfides produced were consistent with gas chromatography of separately synthesized standard identification products.

Claims (1)

[Claims] 1 Thionitrites of the formula R ¹ —SNO [] (wherein, R ¹ represents an alkyl group or an aralkyl group), and thionitrites of the formula R ² —SH [] (wherein, R ² represents an alkyl group or an aryl group) with a mercaptan of the formula R ¹ -S-S-R ² [] (wherein R ¹ is R ¹ of the formula [ ]), R ² is the same as R ² in formula [ ].) A method for producing disulfides.