RU2480000C2 - Method of producing 2-dimethylamino-1,3-bis(phenylthiosulphonyl)propane - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to synthesis of biologically active compounds - insecticide: 2-dimethyl-amino-1,3-bis(phenylthiosulphonyl)propane (Bancol). First, 2-dimethylamino-1,3-dichloropane is obtained by reacting 33-38% aqueous dimethylamine (DMA) solution with allyl chloride (AC) in molar ratio DMA:AC of 1.1-1.5:1.0 for 3-4 hours at temperature of 50-55°C with formation of dimethyl allylamine hydrochloride and, without separation thereof, chlorinated at temperature of 7-13°C for 8-10 hours to obtain 1-dimethylamino-2,3-dichloropropane hydrochloride (1-DMA-2,3-DCP HC). After removing residual chlorine, the 1-DMA-2,3-DCP HC is neutralised with 44-46% aqueous alkali solution in molar ratio 1-DMA-2,3-DCP HC:alkali of 1:1.25-1.5 at room temperature to form 2-dimethylamino-1,3-dichloropropane (2-DMA-1,3-DCP). The 2-DMA-1,3-DCP is separated in form of an amine layer, dried, dissolved in isopropyl alcohol and condensed with sodium benzenethiosulphonate (BTSP) in molar ratio 2-DMA-1,3-DCP: BTSP of 1:2-2.04 for 1.5-2.5 hours at temperature of 70-79°C. The sodium chloride crystals formed are filtered off under a vacuum at 70-75°C. The reaction mass is cooled to 20-10°C and the end product is separated by filtering.

EFFECT: invention increases product output and simplifies the method for production thereof.

3 cl, 2 ex

Description

The invention relates to the field of synthesis of biologically active compounds, in particular, to a method for producing an insecticide - 2-dimethylamino-1,3-bis (phenylthiosulfonyl) propane (bankol, Bensulban, Wikbenon, ruban), which finds use as a highly effective insecticide against Lepidoptera and beetlewing pests crops, in particular against the Colorado potato beetle in potato crops [Melnikov N.N. et al. Pesticides and plant growth regulators / Handbook, M .: "Chemistry", 1995, p.333].

The preparation of bankol is described by the interaction of a solution of 1-dimethylamino-2,3-dichloropropane (1-DMA-2,3-DHN) in ethyl alcohol and sodium ethylate with sodium benzenethiosulfonate (BTSF) in ethyl alcohol at 80 ° C for 2 hours . The precipitated NaCl is filtered off, the solvent is evaporated, the precipitated Bankola crystals (mp 82-83 ° C) are isolated by fractional crystallization due to the good solubility of the target product in ethanol [CH 548381. Verharen zur Herstellung never 2 - Aminopropanverbindungen].

We tested this method in the laboratory, the product yield was 49-51% of theoretical. The disadvantage of this method is the use of an alcoholic solution of raw materials, sodium ethylate, the latter is obtained from anhydrous alcohol and sodium metal, in addition, 1-dimethylamino-2,3-DC is not available in industry. If we summarize all the stages of preparation of raw materials, the process will still be quite complex (multi-stage) and the yield of the target product is not high enough.

The preparation of bankol is also described by mixing 1-dimethylamino-2,3-dichloropropane in ethanol with a calculated amount of BTSF. The mixture is kept at boiling for 2 hours. The NaCl is filtered off, the bankcol is recrystallized from diethyl ether [JP 13755. A method for producing heterocyclic amino compounds]. The yield of the target product 57%. The disadvantage of this method is the use of flammable and flammable liquids and not high enough product yield.

The closest method in terms of technical nature and the achieved result is to obtain a bankol with a yield of 61-62% of theoretical by the interaction of 1-dimethylamino-2,3-DCP and BTSP in a NaOH alcohol solution medium during boiling for 2 hours. [Konishi Kazuo. Studies on organic insecticides Part XIII. Sindesus of nereistoxin and related compounds // Agr. and Biol. Chem., 1970, V.34, N.10, p. 1549-1560]. The disadvantage of this method of obtaining bankola is the difficulty of isolating the target product, because in caustic soda medium, the latter is dissolved in alcohol and it is not clear how to isolate the product from the filtrate in the presence of caustic soda, as well as the insufficiently high yield of the product.

The problem to which the invention is directed, is to develop an improved method for producing 2-dimethylamino-1,3-bis (phenylthiosulfonyl) propane (bankcol) and increasing the yield of the product. The technical result when using the proposed method is expressed in increasing the yield of the target product and simplifying the method of its production.

The above technical result is achieved by the method of producing 2-dimethylamino-1,3-bis (phenylthiosulfonyl) propane by the interaction of 2-dimethylamino-1,3-dichloropropane with sodium benzenethiosulfonate in the presence of a solvent - isopropyl alcohol, the feature of which is the initial preparation of 2-dimethylamino-1 , 3-dichloropropane (2-DMA-1,3-DCP) by the interaction of a 33-38% aqueous solution of dimethyl amine (DMA) with allyl chloride (XA) with a molar ratio of DMA: XA equal to 1.1-1.5: 1.0, for 3-4 hours at a temperature of 50-55 ° C with the formation of hydrochloride dimetilallilamina chloride (DMAC), which without isolation is then chlorinated at 7-13 ° C for 8-10 hours to give the hydrochloride of 1-dimethylamino-2,3-dichloropropane (CH 1-DMA-2,3-DHP). The latter, after removal of chlorine residues, is neutralized with a 44-46% aqueous alkali solution at a molar ratio CG of 1-DMA-2,3-DCP: alkali equal to 1: 1.25-1.5, with the formation of 2-DMA- 1,3-DHP (due to the isomerization of 1-dimethylamino-2,3-DHP), which is separated in the form of an amine layer, dried, dissolved in isopril alcohol and condensed with sodium benzenethiosulfanate in a molar ratio of 2-DMA-1,3-DC : BTSF equal to 1: 2-2.04 for 1.5-2.5 hours at a temperature of 70-79 ° C. The precipitated NaCl crystals are filtered off under vacuum at 70-75 ° C, then the reaction mass is cooled to 20-10 ° C and the precipitated crystals of the desired 2-dimethylamino-1,3-bis (phenylthiosulfonyl) propane are filtered off, yield 79-81.5%. Isopropyl alcohol is taken in 2.0-2.5 times more in relation to the weight of the starting compounds. As alkali, an aqueous solution of sodium hydroxide or potassium is used.

Reaction Scheme:

The advantages of the proposed method are:

- availability of reagents;

- reduction of the stages of obtaining bankola to a minimum;

- the synthesis of bankola in a safe, homogeneous environment and the absence of the use of flammable liquids;

- increased product yield due to the use of isopropyl alcohol and synthesis in a homogeneous phase.

The invention is illustrated by the following examples.

Example 1. 4.95 g (0.11 mol) of DMA in the form of a 33% aqueous solution are loaded into a stirred reactor and 7.65 g (0.1 mol) of allyl chloride are metered in for 1 hour, temperature (50 ° C) of the reaction mixture is supported by a metered supply of allyl chloride, stirred to a constant value of the chlorine ion (2 hours) (according to known methods for the determination of chlorides). Excess DMA is removed with an inert gas and trapped in water. A weak DMA solution can be returned to the production of VPK-402. The resulting product, dimethylallyl amine hydrochloride, is chlorinated without isolation in free form. The reactor is additionally equipped with a rubber outlet for supplying chlorine and, at a temperature of 7 ° C, chlorine is supplied through a bubbler for 8 hours. After chlorination of DMAA hydrochloride is complete, the reaction mixture is blown off with nitrogen for 20-30 minutes. After removal of the residual chlorine, the resulting 1-DMA-2,3-DHP chloride hydrate (the absence of a double bond is determined by the bromine number method) is neutralized with 5.0 g (0.125 mol) of NaOH in the form of a 44% aqueous solution at room temperature (CG neutralization occurs simultaneously 1-DMA-2,3-DHPa and its isomerization to 2-DMA-1,3-DHP). The molar ratio of CG 1-DMA-2,3-DHP: NaOH = 1: 1.25. The reaction mixture is stirred for 0.5-1 hours and a sample is taken for analysis. For this, the sample is treated with a 40% aqueous solution of NaOH, the amine layer is isolated and 2-DMA-1,3-DC is determined by GLC. The reaction mixture was transferred to a separatory funnel, a layer of 2-DMA-1,3-DHPan was separated, dried and loaded back into the reactor, 111 ml of isopropyl alcohol were added, heated to 70 ° C and 39.98 g (2.04 mol) of benzenethiosulfonate were dosed. sodium, maintained at 79 ° C for 1.5 hours. The NaCl was filtered off at 70 ° C. under vacuum. The calculated amount of NaCl is released. The remaining mass is cooled to 10-20 ° C and crystallized light yellow crystals of bancol are filtered off under vacuum and dried under a stream of nitrogen. Isopropyl alcohol is regenerated by distillation. 34.0 g (79%) of product are isolated, T _pl. 83-83.5 ° C.

Calculated,%: S 29.69; N 3.24; C ₁₇ H ₂₁ NS ₄ O ₄ . Found,%: S 29.32; N 3.51.

Example 2. Under the conditions of example 1, 6.75 g (0.15 mol) of DMA in the form of a 38% aqueous solution was loaded into the reactor and 7.65 g (0.1 mol) of allyl chloride was dosed and stirred at 55 ° C in 4 hours to a constant value of the chlorine ion. Excess DMA is removed with an inert gas and trapped in water. The resulting DMAA hydrochloride is chlorinated without isolation in free form at a temperature of 13 ° C for 10 hours. After chlorination is complete, the reaction mass is blown off with nitrogen for 20-30 minutes and 5.85 g of neutralized CH-1-DMA-2,3-DCPa (0 , 15 mol) of potassium hydroxide in the form of a 46% aqueous solution at room temperature. The reaction mixture was stirred at room temperature for 0.5 hours. 2-DMA-1,3-DHP is separated, dried. The molar ratio of CG 1-DMA-2,3-DHP: KOH = 1: 1.5. The resulting 2-DMA-1,3-DCP was transferred to the reactor, 140 ml of isopropyl alcohol were added and 39.2 g (0.2 mol) of sodium benzenethiosulfonate were dosed. The mixture was kept at 70 ° C for 2.5 hours. Precipitated NaCl was isolated by hot filtration at 70-75 ° C under vacuum. The remaining mass is cooled to 20-10 ° C. The precipitated crystals of bankola are filtered off. Obtain 35.1 g (81.5%) of the product, T _pl. 82.5-83.5 ° C. Calculated,%: S 29.69; N 3.24; C ₁₇ H ₂₁ NS ₄ O ₄ . Found,%: S 29.98; N, 3.58.

Claims (3)

1. The method of obtaining 2-dimethylamino-1,3-bis (phenylthiosulfonyl) propane, characterized in that initially receive 2-dimethylamino-1,3-dichloropropane by reacting a 33-38% aqueous solution of dimethylamine (DMA) with allyl chloride (XA) with a molar ratio of DMA: XA equal to 1.1-1.5: 1.0, for 3-4 hours at a temperature of 50-55 ° C with the formation of dimethylallylamine hydrochloride, which is chlorinated without isolation at a temperature of 7-13 ° C for 8-10 hours to obtain 1-dimethylamino-2,3-dichloropropane hydrochloride (CG 1-DMA-2,3-DC), which, after removal of residual chlorine , neutralized with a 44-46% aqueous alkali solution at a CG molar ratio of 1-DMA-2,3-DCP: alkali equal to 1: 1.25-1.5 at room temperature to form 2-dimethylamino-1,3 -dichloropropane (2-DMA-1,3-DHP), which is separated in the form of an amine layer, dried, dissolved in isopropyl alcohol and condensed with sodium benzenethiosulfonate (BTSF) at a molar ratio of 2-DMA-1,3-DCP: BTSF, equal to 1: 2-2.04, for 1.5-2.5 hours at a temperature of 70-79 ° C, followed by filtering out crystals of sodium chloride under vacuum at 70-75 ° C, cooling the reaction mass to 20-10 ° C and you dividing the target product by filtration. 2. The method according to claim 1, characterized in that as the alkali use an aqueous solution of sodium hydroxide or potassium. 3. The method according to claim 1, characterized in that the isopropyl alcohol is taken 2-2.5 times more with respect to the weight of the starting compounds.