SU1664794A1 - Method for obtaining 2,2,4-trimethyl-1,3-dithiolane - Google Patents

Abstract

The invention relates to derivatives of heterocyclic substances, in particular the preparation of 2, 2, 4-trimethyl-1, 3-dithiolane, which can be used as an extractant and complexing agent. The goal is to increase the yield of the target compound and increase the selectivity of the process. The latter is carried out by the reaction of allene with carbon disulfide at a molar ratio of 0.5: (0.25 - 0.30) in dimethylformamide or acetonitrile in the presence of a catalyst containing acetylacetonate or cobalt acetonate, an organophosphorus compound (diphenylphosphinoethane or isopropyl phosphite), carbon monoxide and ammonia at a molar ratio of NI or CO: P: CO ₂ : NH ₃ = (0.5 @ 1.0) :( 1 @ 5) :( 30 @ 50). Output 75 - 78%, t _KIP 42 ° C / 1 mm Hg. Art., the gross formula C ₆ H ₁₂ S ₂ . These conditions make it possible to increase the yield of the target product by 70–83% and increase the selectivity of the process to 100%. 1 tab.

Description

The invention relates to the chemistry of heterocyclic compounds, specifically to an improved method for the preparation of 2,2,4-trimethyl-1,3-dithiolane (I), which can be used as an effective extractant, complexing agent, as well as substances included in the composition. biologically active compounds.

The aim of the invention is to increase the yield of compound I and increase the selectivity of the process.

The goal is achieved by reacting allen with carbon disulfide at a molar ratio of 0.5: (0.25-0.3) in dimethylformamide or acetonitrile in the presence of a catalyst containing Ni or Co acetylacetonates, organophosphorus ligand (diphenylphosphinoethane, isopropyl phosphite) carbon monoxide and ammonia, the molar ratio of the components Me2 +: P: C02: NH3 (0.5-1.0) :( 1-5): 30: 50 at 140-150 ° С.

PRI me R. A catalytic mixture prepared from 0.4 g of Co (acac, 0.5 g (Ph2PCH2) 2 and 25 ml of DMF in an argon atmosphere, 0.5 M allene (30 ml), 0, 25 M CSa (-47 ml) and 0.5 M NHa (Yu ml). The autoclave is closed and injected with CO2 (50 atm, 0, 3M). The reaction mixture is heated at 150 ° C for 20 h, then cooled, the catalyst is extracted with sulfuric ether ( 10C ml), washed with 10% HC1 and water. The organic layer was dried over N32SO4. After removing the solvent, 36 g (85%) of 2,2,4-trimethyl-1,3-dithiolane were obtained, bp - 42 ° C (1 mmHg) 5025.

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NMR-cp $ ctr (13C) 2.2 /, 4-trimethyl-1,3-dithio anad / ppm: 62.02 (C2); 51.80 (C4); 46.47 t (C% 33.28 c (C6); 35.28 c (C7); 19.98 c (C8).

The table shows the research data in the examples.

Thus, the proposed method for producing 2,2,4-trimethyl-1,3-dithiolane allows an increase in the yield of the target product by 70-83% and an increase in the selectivity of the process.

Claims (1)

Invention Formula The method of obtaining 2.2 //, 4-trimethyl-1,3-dithiolane by reacting unsaturated hydrocarbon with sulfur-containing compound in the medium of an organic solvent in the presence of catalyst salts of metals at elevated temperatures, characterized in that in order to increase the yield of the target product and increase the selectivity of the process, allene is used as a unsaturated hydrocarbon. as a sulfur-containing compound, carbon disulfide, as organic solvent - dimethylformamide or acetonitrile, as a catalyst - a mixture of nickel acetylacetonate or cobalt acetylacetonate, organophosphorus compound {diphenylphosphinoethane or isopropylphosphite) - carbon monoxide and ammonia, taken in a molar ratio of (0.5-1.0) :( 1.0-5.0): 30:50, and the process is carried out at a molar ratio of allene: carbon disulfide 0.5: (0,25-0,30).