SU1467059A1 - Method of producing dimethyl(2,2-dimethyl-4,6-dioxo-1,3-dioxamino-5-ilidene) dithiocarbonate - Google Patents

Abstract

The invention relates to derivatives of 1,3-dioxane, in particular the preparation of dimethyl (2,2-dimesh1-4,6-dioxo-I, 3-dioxano-5-ylidene) dithiocarbonate, used as an antisecretory agent in medicine. The process of redoubt from Meldrum acid, carbon disulfide and СНд in the presence of KOH or NaOH with their molar ratio is 1: 1: 2: 2 in ethanol. These conditions ensure a higher yield of the target product and simplify the process by reducing the reaction time by 2 times and using more accessible and non-explosive reagents. 1 hp f-ly, 1 tab.

Description

one

The invention relates to an improved process for the preparation of dimethyl (2,2-dimethyl-4,6-dnoxo-1,3-wild with an-5-nlide-ene). ditiok arbat ata, which can be used in medicine as an antisecretory agent.

The purpose of the invention is to increase the yield of the target product and to hinder the process technology by: using ethanol as an organic solvent, and potassium or sodium hydroxide as a base.

Example 1. To a mixture of 25.5 g (0.177 mol) of Meldrzgma acid and 8.27 ml (13.5 g of 0.177 mol) of carbon disulfide in 100 ml of ethanol slowly pour at 10-12 ° С a solution of 20 g (0.354 mol) of 85% Mr. KOH 150 ml

ethanol. The resulting mixture was stirred for 4 hours at room temperature, 20.6 ml (51 g, 0.354 mol) of methyl iodide was added and the mixture was stirred

4 hours at room temperature. The precipitate is filtered off, the filtrate is evaporated to dryness on a rotary evaporator. The residue is recrystallized from ethyl acetate-hexane. The output of dimethyl (2,2-dimethyl-4,6-dioxo-1,3-dioxane-5-igsden) -dithiocarbonate (G) 28.6 g (65%), so pl. 116-118 s.

Found,%: C 24.45; H 2.31;

514.58.

Calculated,%: C 24,11; H 2.68; S 14.29.

PNR spectrum (60 MHz, CDCl,), ppm: 1.41 (s, 6H, C (CH,),), 2.2 (s, 6H, 2CH,).

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Example2. To a mixture of 14.4 g (0.1 mol) of Meldrum acid and 6 ml (7.7 g, 0.1 mol) of carbon disulfide in 70 ml of ethanol a solution of 8 g (0.2 mol) is slowly poured in at 10-12 ° C NaOH in 100 ml of ethanol. The resulting mixture was stirred at room temperature for 2 h., 2.0 ml (28.4 g,

PrimerZ, To a mixture of 14.4 g (0.1 mol) of Meldrun acid and 6 ml (7.6 g, 0.1 mol) of carbon disulfide in 70 ml of ethanol, a solution of 11.3 g (0 , 2 mol) of 85% KOH in 100 ml of ethanol. The resulting mixture was stirred for 4 hours at 5-10 ° C, 12 ml (28.4 g.

Oi, 2 mol) of methyl iodide perimeter mol of methyl iodide, stirred at room temperature for 4 hours. The precipitate is filtered off, the filtrate is evaporated to dryness on a rotary evaporator. The residue is recrystallized from ethyl acetate-hexane. The product yield (T) 15.8 g (64%).

Ethanol is the most convenient polar solvent for carrying out the addition. It is possible to use and dilute others for 8 hours at 5-10 C. The precipitate KI is filtered off, the filtrate is evaporated to dryness on a rotary evaporator. The residue is recrystallized from a mixture of 15 ethyl acetate-hexane. The product yield (T) of 14.8 g (60%).

Example4. To a mixture of 14.4 g (Op1 mol) of Meldrum acid and 6 ml (7.6 g, .0.1 mol) of carbon disulfide in

for example, methanol, propa-20 70 ml of ethanol are slowly poured

Nola, DMSO, DMF, but these options are associated either with high toxicity (methanol, propanol) or with high cost and difficulty removing solvent (DMSO, DMF).

The choice of temperature conditions due to the following. Carrying out the reaction at room temperatures does not substantially affect the output, but increases the reaction time.

Comparison of the temperature conditions for obtaining the target product is given in the table.

10-12 ° C. A solution of 11.3 tons (0.2 mol) of 85% KOH in 100 ml of ethanol. The resulting mixture was stirred for 3 hours at 30-40 ° C, 12 mp (28.4 g,

25 0.2 mol) of methyl iodide, stirred for 2 hours at room temperature at 30-40 ° C. The precipitate is filtered off, the filtrate is evaporated to dryness on a rotary evaporator. Dark, tarry

30 The residue is recrystallized several times from ethyl acetate-hexane. The product yield (1) 9.9 g (40%)

Example5. To a mixture of 14.4 g (0.1 mol) of Meldrum acid and 6 ml

An increase in the process temperature above room temperature (25 ° C) is accompanied by a slight decrease in the yield and atmoleration of the product, the reaction.

Thus, the optimal process conditions are achieved at 15-25 ° C and a process time of 8 hours.

In the process, the reagents are used in an equimolar ratio, which is due to the reaction stoichiometry,

PrimerZ, To a mixture of 14.4 g (0.1 mol) of Meldrun acid and 6 ml (7.6 g, 0.1 mol) of carbon disulfide in 70 ml of ethanol, a solution of 11.3 g (0 , 2 mol) of 85% KOH in 100 ml of ethanol. The resulting mixture was stirred for 4 hours at 5-10 ° C, 12 ml (28.4 g.

 mol) methyl iodide, stirred for 8 h at 5-10 C. The precipitate KI is filtered off, the filtrate is evaporated to dryness on a rotary evaporator. The residue is recrystallized from ethyl acetate-hexane. The product yield (T) of 14.8 g (60%).

Example4. To a mixture of 14.4 g (Op1 mol) of Meldrum acid and 6 ml (7.6 g, .0.1 mol) of carbon disulfide in

0 ml of ethanol is slowly poured

10-12 ° C. A solution of 11.3 tons (0.2 mol) of 85% KOH in 100 ml of ethanol. The semi-mixed mixture is stirred for 3 hours at 30-40 ° C, 12 mp (28.4 g,

0.2 mol) of methyl iodide, stirred for 2 hours at room temperature 30-40 ° C. The precipitate is filtered off, the filtrate is evaporated to dryness on a rotary evaporator. Dark, tarry

the residue is recrystallized several times from ethyl acetate-hexane. The product yield (1) 9.9 g (40%)

Example5. To a mixture of 14.4 g (0.1 mol) of Meldrum acid and 6 ml

(7.6 g, 0.1 mol) of carbon disulfide in 70 MP of ethanol slowly add a solution of 11.3 g (0.2 mol of 85% KOH to 100 MP of ethanol at room temperature. The mixture heats up quickly, foaming occurs and the reagents are released from the reaction vessel.

The advantage of the proposed method is to increase the yield

target product from 8.6 to 65% and

simplifying the process by reducing the reaction time of using potassium or sodium hydroxide in ethyl alcohol instead of expensive and flammable sodium hydride in DMF and benzene.

Claims (2)

1. The method of producing dimethyl (2,2-dimethyl-4,6-dioxo-1, 3-dioxan-5-ylidene) dithiocarbonate by the interaction of Meldrum acid with carbon disulfide in an organic solution5 14670596 the bodies in the presence of a base with a potassium or sodium sitter and a process by treating the reaction mixture at a molar ratio with methyl iodide, distinguished by Meldrum, carbon disulfide, iodine depletion and with the fact that, with the aim of increasing methyl and base equal to 1: 1: 2: no yield of the target product and up-: 2, respectively, at 0-25 ° C. process, as an organized 2. The method according to claim 1, which uses a distinctive solvent, this and that with the fact that the process is pierced, as the base is hydro-water at 15-25 seconds for 8 hours.