SU792852A1 - Process for producing aromatic disulfides - Google Patents

Description

(54) METHOD FOR OBTAINING AROMATIC DISULFIDES

The invention relates to an improved method for the preparation of aromatic disulfides of the general formula -5 (I) where A is α-aminophenyl, lower alkyl; 1-aminophenyl, aminonaphthyl or aminopyridine, which can be used in the synthesis of polymers, as stabilizers of heat-resistant polymers and initiators ( {yutopolimerizatsii, as well as insecticides and fungicides. A known method for producing aromatic disulfides of the formula (I), in particular bis- {4-dimethylaminophenyl) -disulfide, by the interaction of benzene solution of dichloride sulfur with N, KH-Dimethyl-amylin while maintaining a temperature of 20-25 o. The disadvantages of this method are from using in the process of poisonous sulfur dichloride and toxic benzene, as well as the need for temperature control of the process of rapid reaction. The closest to the present invention is a method for the preparation of aromatic disulfides of formula (1), namely, the corresponding aryl halide is reacted with 1p6 with thiourea by irradiation with UV light and a temperature of 20-25 ° C in an aqueous or aqueous-alcoholic solution, for example, water tert-butyl alcohol. The corresponding thiourea derivative thus obtained is hydrolyzed with an alkali metal hydroxide when boiling in an inert gas, for example argon, or nitrogen, followed by acidifying 4 of the reaction mixture, for example, with hydrochloric acid and oxidizing the resulting mercaptan with -air oxygen. The desired product is isolated by known methods, for example, extraction with ether, drying and recrystallization, with a yield of 50-75% 2. However, the disadvantages of the known v method are the relatively low yield and purity of the target products. The purpose of the invention is to increase the yield and purity of the target products. The goal is achieved when implementing the described method of obtaining aromatic disulfides of formula (I), which consists in the fact that the corresponding aryl halide is exposed to thiosemicarbazide when irradiated with UV light to a temperature of 20-25 ° C, an aqueous-alcoholic solution, thus obtained the corresponding thiosemicarbazide derivative is hydrolyzed about alkali metal, in boiling in an inert gas medium, followed by acidification of the reaction mixture by oxidation of the resulting NH2 ArHa {-bS C NH- NHg and solutions and isolation of the final product are of the same type. At the end of photolysis, tert-butyl alcohol is extracted with ether. Aether. the extract is washed with water, the aqueous extracts are connected to an aqueous residue and alkaline hydrolysis is carried out with caustic feces (4 g) while boiling in an argoAr-S-C KH-NH2 atmosphere. In the case of p-chloro-N, N-dimethylanyl, the disulfide is extracted with ether. The ether is dried with sodium sulfite, the solvent is distilled off. Disulfide is purified by recrystallization. In the remaining cases, the precipitates are filtered, and they are collected on the filter. EXAMPLE 1, O, 5 gp-chloro-N, N-d methylaniline (m.p. 35c) is dissolved in 15 O ml of tert-butyl alcohol (ppm) and mixed with 2.5 g of thiosemicarbazvda (x.4.) dissolved in 200 mA of water. The reaction solution prepared in this way is placed in a quartz reactor with a submerged burner and irradiated for 3 hours with argon (nitrogen) under stirring. At the end of photolysis, the reaction solution is extracted with ether (3 -150 m. The ether extracts are combined and washed with water (). The aqueous extracts are added to the aqueous residue, 4 g of KOH are added and the mixture is boiled under argon for 20 minutes. The target product is obtained by the well-known methods - extraction, solid, recrystallization with a yield of 70-85%. The process consists in the following. The reaction is carried out by irradiating with the UV light of water-alcohol solutions of aromatic halogenes and thiosemicarbazide. full spectrum of the medium pressure mercury lamp (DRL-400) through the submerged cooler, cooled with water in the reactor of the 350 ml capacity with stirring with argon and a temperature of 20-; 25 ° C The ratio of t-butyl alcohol to water is 3: 4 by volume. r-S-C NH-NHg; to prevent the oxidation of mercaptan under these conditions. The resulting aryl mercaptide potassium, after cooling the solution to room temperature and acidifying the reaction solution with concentrated HCE to pH 8, is oxidized with atmospheric oxygen, bubbling air through the solution. Ar-S-S-Ar. The solution is then cooled to room temperature, acidified to pH 8 and air is bubbled for 6 hours. The resulting bis (4-dimethylaminophenyl) disulfide is extracted with ether (ml). The ether is dried. The residues weigh. 36O g (76%), so pl. 117C. After recrystallization from hexane so pl. . When melting with bis (4-dimethylaminodiphenyl) -disulfivd, which is completed by a known depression method, m.p. no mixing samples are given. EXAMPLE 2. From 0.5 g of p-chloroaniline and 2.5 g of thiosemicarbazide, after irradiation for 1.5 h and treatment of the reaction solution in the manner described, 39O mg (8O%) are obtained. colorless needle-like crystals of bis- (4-amnophenyl) -disulfide with so pl. after recrystallization from hexane so pl. . When melting with bis (4-am number.

nofenil) -disulfide, obtained by a known method, depression t. pl. sample does not mix.

Example 3 From O, 5 g of 1-amino-4-bromonaphthalene and 2.5 g of thiosemicarbazide, after irradiation for 2 hours and treating the reaction solution, a yellow amorphous precipitate is obtained in a manner described, which is filtered and dried. Weight 275 mg (70%); m.p. 165С. After cleaning the decantation with ethanol so pl. 167 ° C. When melting with bis- (4-aminonaphthyl) disulfide, synthesized by a known method, depression so pl. sample does not mix.

Bis44-aminophenyl) disulfide

Bis (4-dimethylaminophenyl) -disulfide

Bis44-aminonaphthyl) disulfide

ling

2-AMINO-5- Bis (2-amino-chloro-pyridine-5-pyridyl) disulfide The table shows that the proposed method provides a higher yield and high purity of the crude product. formula of the invention A process for the preparation of aromatic disulfides of the general formula ftr-S-5- / If, where AG-aminophenyl, di-lower alkylaminophenyl, aminonaphthyl, or. aminopyridinyl based on the corresponding aryl halo-

Example 4 From 0.5 g of 2-amino-5-chloropyridine and 2.5 g of thiosemicarbazide, after irradiation for 1 hour and treating the solution in the manner described, 420 mg (85%) of colorless flaky bis crystals are obtained. (2-amino-5-pyridyl) disulfide, so pl. 178-1. After recrystallization of aqueous alcohol, m.p. 18O-181 C. When melting with a bis (2-amino-5-pyridyl) disulfide, synthesized according to the well-known method, depression t. Pl. sample does not mix.

The table shows the results of the comparative data of the known and proposed methods.

50.73

80.76

75, 117

65,115

7O, 165

55, 132

75 175

85 178-179 using the reaction of irradiation of UV light at a temperature of 20-25 ° C in an aqueous-alcoholic solution, alkaline hydrolysis by boiling in an inert gas, acidifying the reaction mixture and subsequent oxidation of the corresponding mercaptan: oxygen air, characterized in that, in order to increase the yield and purity of the target product, thiosemicarbazide is subjected to interaction with irradiation with UV light with the corresponding aryl halide followed by subsequent silk

7 7928528

hydrolysis of the corresponding-l.Mierz, w .Wejt-h. vX /. Obtaining the corresponding derivative of thiosemicaric aminodisulfide, Vec,

basidic acidification of the reaction mixture (1886), 19.1571.

and the oxidation of the resulting ratio -2. USSR author's certificate

stem mercaptan. 5 STACK No. 2638742 / 23-04,

Sources of information, cl. C O7 C 149/42, 10. 07.78 (taken into account during the examination of the type).

Claims (1)

Claim The method of obtaining aromatic disulfides of the General formula Ar - s - 5 - Ar where Ar is aminophenyl, lower alkylamino phenyl, aminonaphthyl, or aminopyridinyl, based on the corresponding aryl halide using the reaction of irradiation with UV light at a temperature of 20-25 ° C in an aqueous-alcohol solution, alkaline hydrolysis'-by boiling in inert gas, acidification of the reaction mixture and subsequent oxidation of the corresponding mercaptan formed: with atmospheric oxygen, characterized in that, in order to increase the yield and purity of the target product ⁵⁵ , interaction during irradiation Thiosemicarbazide is subjected to UV light with the corresponding aryl halide followed by sequential alkaline 7 792852 8 by hydrolysis of the corresponding thiosemicarbazide derivative thus obtained, acidification of the reaction mixture and oxidation of the corresponding corresponding mercaptan.