Method of producing 1-adamantane carboxylic acid

FIELD: chemistry.

SUBSTANCE: invention relates to pharmaceutical chemistry, specifically to a method of producing 1-adamantane carboxylic acid which is a basic intermediate product in production of antiviral agent ramantadin. The method of producing 1-adamantane carboxylic acid is realised through carboxylation of 1-nitroxyadamantane with methanoic acid in the presence of sulphuric acid. 1-nitroxyadamantane is dissolved in 93.0-96.0% sulphuric acid containing 0.7-1.0 moles of urea. Methanoic acid or its salt is added in amount of 1.5-2.0 mol per mole of 1-nitroxyadamantane and held at temperature 18-20°C for 4-24 hours. The reaction mass is diluted with water at temperature 90-95°C and held at temperature 80-90°C for 30-40 minutes to complete hydrolysis of the formed 1-nitrourea and 1,3-dinitrourea. Adamantane carboxylic acid is the cooled and filtered. Output of the end product with melting point of 177-180°C is theoretically equal to 90-99%.

EFFECT: design of an efficient method of obtaining 1-adamantane carboxylic acid.

3 cl, 8 ex

 

The invention relates to the field of pharmaceutical chemistry, in particular to a method for producing 1-adamantanecarbonyl acid (1-ACC), the primary intermediate product in the synthesis of medicinal drug rimantadine.

There are a large number of ways to obtain 1-ACC. They are all based on the carboxylation reaction of adamantane and its derivatives containing in position 1 such substituents as bromine, hydroxy - or nitroxide, with formic acid in the environment 97-100%sulfuric acid by the reaction, an open-Koch-Hatom. Because of the very low solubility of adamantane in sulfuric acid the reaction is usually carried out in the presence of organic solvents, such as hexane, chlorinated hydrocarbons, tert-butanol, etc.

Thus, according to the patent of the Russian Federation 2118313 the carboxylation adamantane is carried out in a mixture of 97-100%sulfuric acid, carbon tetrachloride and tertiary butanol formic acid. Output adamantanecarbonyl acid reaches 80%. However, as was demonstrated by another Koch and Haaf (Angew. Chem. 1960, t, str), in these conditions simultaneously with adamantanecarbonyl acid is formed pavlikova acid with the yield up to 87% for parallel running of the carboxylation reaction of tertiary butanol. The spent acid after dilution with water is a complex mixture of sulfuric acid with organic products, processing which is predstavljaet very complex problem. It is well known that sulfuric acid and carbon tetrachloride to form phosgene.

The carboxylation of 1-nitroacetophenone, according to the mosaic I.K. and Doroshenko R.I. (J. Orghim., 1983, t, str), can be implemented in the absence of organic solvents exit 1-ACC 96% with MP. 178-179°C. as a prototype we have chosen this work.

Optimum conditions for maximum output 1-ACC, are: a reaction temperature of 20-22°C, reaction time of 1 hour, the molar ratio of sulfuric acid, formic acid and nitrosoanabasine 9,8:12:1. This method of obtaining 1-ACC selected by the authors as the closest equivalent.

Multiple experimental verification of the method of Moses and Doroshenko has shown that he has a very major shortcomings, namely:

- exit 1-ACC raw is 59-60% instead of 94%, as stated in the work;

the melting point of the product raw is a very wide range from 170° to 250°C, which indicates the complex composition of the mixture.

Analysis of the obtained products showed that they contain 40-60% high-melting by-products, the main of which is 1,3-adamantanecarbonyl acid with MP. in its pure form 267-268°C.

Education impurities 1,3-adamantanecarbonyl acid at the carboxylation of 1-nitrosoanabasine formic acid explains p is our opinion, the course of the following reactions. It is well known that nitrates alcohols in the environment of sulfuric acid are subjected to the reactions of hydrolysis and transesterification with the allocation of free nitric acid, therefore, in an environment of concentrated sulfuric acid forms a complex equilibrium mixture of products

Also it is well known that 1-nitrosoamine easily nitroade in position 3 with the formation of 1,3-dinitrostilbene (Moiseev I.K. and other J. Org. chem. 1995, v.9, str-215) even when the nitration adamantane only nitric acid

The resulting 1,3-dinitrobutane, according to the same authors, carboxylases in the environment of sulfuric acid to 1,3-adamantanecarbonyl acid.

The problem to which this invention is directed is to provide a method for obtaining 1-ACC, providing higher yield of the target product and high quality education waste solutions of acids that can be processed by known methods.

This object is achieved by a new method of obtaining 1-ACC, which is as follows.

1-Nitrosoamine dissolved in 93-96%sulfuric acid, which is pre-mixed urea in the amount of 0.7÷1 mol per mol of 1-nitrosoanabasine and the ATEM formic acid or its salts in a quantity of 1.5 to 2.0 mole per mole of 1-nitrosoanabasine, maintained at a temperature of 18-20°C for 4-24 hours to complete carboxylation and dilute the reaction mass at a temperature of 90-95°C, then maintained at a temperature of 80-90°C 30-40 minutes to complete the hydrolysis of the formed 1-nitrocefin and partially 1,3-dinitramine to gaseous products. At the stage of carboxylation instead of formic acid, you can use it more accessible salt is sodium, potassium or ammonium.

At the stage of dissolution 1-nitrosoanabasine in 93-96%sulfuric acid, nitric acid, formed by the equation (1), quickly associated with urea with the formation of 1-nitrocefin and partially 1,3-dinitramine.

Due to these reactions is precluded its further involvement in the formation of 1,3-dinitrostilbene by the equation (2) or other similar nitrosopropane 1,3-disubstituted adamantane. Accordingly eliminated and the formation of 1,3-adamantanecarbonyl acid, as high-melting impurities to 1-ACC.

The resulting 1-nitrocefin does not interfere with the reactions of carboxylation of 1-hydroxyadamantane formed according to reaction (1). To obtain pure 1-ACC must be removed 1-nitrocefin. The reaction of decomposition of 1-nitrocefin and 1,3-dinitramine easily flows when diluted and water at a temperature of 80-95°C with the formation of gaseous products in equations (6) and (7).

Carbon dioxide and monoxide nitrogen emitted, and ammonia associated with the formation of ammonium bisulfate, which does not interfere with the recycling and reuse of the regenerated sulfuric acid, in contrast to all of the ways to obtain 1-ACC using solvents or chlorinated hydrocarbons and tert-butanol.

Output 1-ACC by our proposed method reaches 96-98% and provides high quality product. The product melts at 178-180°C.

A significant factor affecting the quality of the obtained 1-ACC, is the concentration of the used sulfuric acid. We found that the use of oleum and even 97-100% sulfuric acid forms a dark-colored reaction mass. The formation of colored products, clearly associated with adverse reactions to the deep destruction adamantanol frame. The use of sulfuric acid with a concentration of 93-96% minimizes the formation of dark-colored by-products 1-ACC allocated after the decomposition of a 1-nitrocefin at 90-95°C represents a completely white product, in contrast to methods using a more concentrated sulfuric acid. When using 93-96%sulfuric acid complete dissolution of 1-nitrosoanabasine in the presence of 1 mole of urea is achieved when mA is sovam the ratio of sulfuric acid to 1-nitroksidnye 8-9:1. In the optimized conditions on concentration and quantity of sulfuric acid for the full carboxylation of the resulting 1-hydroxyadamantane 1.5-2.0 moles of formic acid per mole of 1-nitrosoanabasine.

The use of sulfuric acid with a concentration of less than 93% significantly slows down the carboxylation reaction.

The examples below explain the essence of the invention.

Example 1

To 90 ml of sulfuric acid of a concentration 93,6% at a temperature of 5-10°C. was added upon cooling, 4.0 g of urea (0.7 mol/mol) and then when cooled was added in small portions 18.0 g of 1-nitrosoanabasine, while maintaining the temperature of 3-5°C. Add 1-nitrosoanabasine usually requires about 20 minutes Then gave exposure 10 min to dissolve the 1-nitrosoanabasine and at a temperature of 2-4°C was dosed out 8 ml of 90%formic acid for 40-45 minutes, gave exposure 2 hours while cooling, and then allowing the temperature to rise to 18-20°C and held at this temperature for another 4 hours. The resulting homogeneous solution was added to 220 ml of water, heated to 70°C. While immediately crystallizes 1-adamantanecarbonyl acid (1-ACC) and the intensive gassing. After pouring the reaction mass was heated slurry at 80-90°C for 30-40 minutes. After 15 minutes gassing almost prikrashatisya was cooled to room temperature, was filtered, thoroughly washed with water and dried at 100-110°C to constant weight. The output of 14.76 g (90% of theory). MP. 178-180°C. the IR spectrum of the product is identical with the spectrum of the sample obtained by the method of Koch-Haifa from adamantane.

Example 2

The reaction was carried out as described in example 1, but to complete the process of carboxylation reaction mass was left at room temperature for 24 hours. Other operations are carried out analogously to example 1. Output 1-ACC 16.3 g (99% of theory). MP. 177-180°C.

Example 3

The reaction was carried out as described in example 1, but instead of 8 ml of 90%formic acid was used to 11.5 g of ammonium formate. The reaction mass before dilution was kept for 24 hours. Output 1-ACC of 14.7 g (89% of theory). MP. 177-180°C.

Example 4

The reaction was carried out as described in example 1, but instead of 8 ml of 90%formic acid was used to 18.6 g of sodium formiate. The reaction mass before dilution was kept for 24 hours. Received 12.4 g (77% of theory) 1-ACC. MP. 178-180°C.

Example 5

The reaction was carried out as described in example 1, using 6 g of urea (1 mol/mol). Received 16.3 g (99% of theory) 1-ACC. MP. 178-180°C.

Example 6

The reaction was carried out as described in example 1, but given holding 10 hours at room temperature. Other operations are carried out analogously to example 1. Output 1-ACC of 15.3 g (93% of theory). MP. 177-180°C.

Example 7

The reaction was carried out as described in example 1, but given holding 18 hours at room temperature. Other operations are carried out analogously to example 1. Output 1-ACC to 15.8 g (96.5% of theory). MP. 177-180°C.

Example 8

The reaction was carried out as described in example 1, but using 96%sulfuric acid. The reaction mass before dilution was kept for 24 hours at room temperature. Output 1-ACC 15.7 g (96% of theory). MP. 177-180°C.

1. A method of obtaining a 1-adamantanecarbonyl acid by carboxylation of 1-nitrosoanabasine formic acid in the presence of sulfuric acid, characterized in that 1-nitrosoamine dissolved in 93,0-96,0%sulfuric acid containing 0.7 to 1.0 mol of urea, add formic acid or its salts in a quantity of 1.5 to 2.0 mole per mole of 1-nitrosoanabasine and maintained at a temperature of 18-20°C for 4-24 h, dilute the reaction mixture with water at a temperature of 90-95°C and maintained at a temperature of 80-90°C 30-40 minutes to complete the hydrolysis of the resulting 1-nitrocefin and 1,3-dinitramine then adamantanecarbonyl acid is cooled and filtered.

2. The method according to claim 1, characterized in that as carboxylases tools use sodium or potassium, or ammonium salt of formic acid.

3. The method according to claim 1, characterized in that the reaction of carboxylases the use of 93-96%sulfuric acid in the amount of 8.0 to 9.0 parts per 1 part 1-nitrosoanabasine.



 

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FIELD: chemistry.

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16 cl, 5 dwg, 7 ex, 8 tbl

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16 cl, 10 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of purifying carboxylic acid from a mixture which contains one or more carboxylic acids selected from a group consisting of terephthalic acid, isophthalic acid, orthophthalic acid and their mixtures, and also contains one or more substances selected from a group consisting of carboxybenzaldehyde, toluic acid and xylene. The method involves: bringing the mixture into contact with a selective solvent for crystallisation at temperature and in a period of time sufficient for formation of a suspension of a complex salt of carboxylic acid with the selective solvent for crystallisation without complete dissolution of the complex salt of carboxylic acid; extraction of the complex salt and decomposition of the complex salt in the selective solvent for crystallisation in order to obtain free carboxylic acid. The mixture containing unpurified carboxylic acid is brought into contact with the selective solvent for crystallisation in order to form a suspension of a complex salt of carboxylic acid with the selective solvent for crystallisation. The complex salt is extracted and, if desired, processed for extraction of free carboxylic acid.

EFFECT: methods are especially suitable for purifying aromatic dibasic carboxylic acids such as terephthalic acid, and also enables reduction of the degree of contamination of phthalic acids with carboxybenzaldehyde isomers.

22 cl, 3 tbl, 1 dwg, 3 ex

FIELD: process engineering.

SUBSTANCE: invention relates to removal of impurities and mother solution and wash filtrate extraction from oxidising reactor discharge flow formed in synthesis of carboxylic acid, usually, terephthalic acid. Proposed method comprises: (a) directing oxidised flow in zone of enrichment by solid particles to settle solid particles and form dumping flow suspension via cooling it, adding settling agent, removing solvent or combining said cooling and adding; (b) separating dumping flow suspension in separation zone to form filter pad and mother solution and forced flushing of said filter pad at high pressure in said separation zone by flushing fluid flow comprising water and, not obligatorily, solvent to form washed pad. Note here that said separation zone comprises at least one filter device operated at pressure and comprising at least one filter cell. Note also that said filter cell accumulates layer of filter pad with depth of at least 0.635 cm (0.25 inch), "c" directing at least a portion of flushing filtrate and at least a portion of mother solution to oxidising zone.

EFFECT: higher efficiency.

44 cl, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing highly pure terephthalic acid which involves the following steps: (a) an oxidation reaction, where p-xylene is oxidised in an acetic acid solution in the presence of a catalyst to form terephthalic acid, (b) obtaining crystals of crude terephthalic acid, where the suspension containing the precipitate of the obtained terephthalic acid is separated into a solid phase and a liquid to obtain crystals of crude terephthalic acid, (c) hydrogenation step, where crystals of crude terephthalic acid are dissolved in water to form an aqueous solution which is hydrogenated, (d) crystallisation of highly pure terephthalic acid, where terephthalic acid is crystallised from the hydrogenated aqueous solution to form a suspension of highly pure terephthalic acid, (e) obtaining crystals of highly pure terephthalic acid, where the suspension of highly pure terephthalic acid is separated into a solid phase and a liquid to obtain crystals of highly pure terephthalic acid and a primary mother solution, and (f) extraction of p-toluic acid from the primary mother solution and taking it to the oxidation reaction step, where the p-toluic acid extraction step includes the following steps: (I) adsorption step, where primary or secondary mother solution, obtained by cooling the primary mother solution in order to separate the solid phase and liquid, is fed in form of treated liquid into an adsorption column filled with an adsorption agent, where the p-toluic acid breakthrough time is greater than that of benzoic acid, for adsorption of p-toluic acid and benzoic acid from the treated liquid on the adsorption agent, (II) cutting supply of the treated liquid into the adsorption column for at a certain moment in time when concentration of benzoic acid in the effluent from the adsorption column reaches at least 10% of the concentration of benzoic acid in the treated liquid, (III) desorption step, where a desorption agent in form of acetic acid, methylacetate or their mixture is fed into the adsorption column for desorption of the adsorbed p-toluic acid and (IV) circulation step, where p-toluic acid contained in the desorption agent flows from the adsorption column and taken to the oxidation reaction step.

EFFECT: design of a method of obtaining highly pure terephthalic acid through selective extraction of p-toluic acid from waste water currently released, and use of the waste water as raw material for producing terephthalic acid.

19 cl, 6 dwg, 5 ex, 1 tbl

FIELD: chemistry.

SUBSTANCE: method involves, for example: (a) evaporation of said oxidised discharge stream, containing terephthalic acid, metallic catalyst, impurities, water and solvent, in the first zone of an evaporator to obtain a vapour stream and a concentrated suspension of the discharge stream; and (b) evaporation of the said concentrated suspension of the discharge stream in the second zone of the evaporator to obtain a stream rich in solvent and a high-concentration suspension of the discharge stream, where the said second zone of the evaporator has an evaporator operating at temperature ranging from 20°C to 70°C, where from 75 to 99 wt % of the said solvent and water is removed by evaporation from the said oxidised discharge stream at step (a) and (b); (c) the said high-concentration suspension of the discharge stream is filtered in a zone for separating solid products and liquid to form a filtered product and a mother liquid; (d) washing the said filtered product using washing substances fed into the said zone for separating solid products and liquid to form a washed filtered product and washing filtrate; and dehydration of the said filtered product in the said zone for separating solid products and liquid to form a dehydrated filtered product; where the said zone for separating solid products and liquid has at least one pressure filtration device, where the said pressure filtration device works at pressure ranging from 1 atmosphere to 50 atmospheres; (e) mixing water and optionally extractive solvent with the said mother liquid and with all of the said washing filtrate or its portion in the mixing zone to form an aqueous mixture; (f) bringing the extractive solvent into contact with the said aqueous mixture in the extraction zone to form a stream of extract and a purified stream, where the said metallic catalyst is extracted from the said purified stream.

EFFECT: improved method of extracting metallic catalyst from an oxidised discharge stream obtained during production of terephthalic acid.

36 cl, 3 dwg, 2 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to pharmaceutical chemistry, specifically to a method of producing 1-adamantane carboxylic acid which is a basic intermediate product in production of antiviral agent ramantadin. The method of producing 1-adamantane carboxylic acid is realised through carboxylation of 1-nitroxyadamantane with methanoic acid in the presence of sulphuric acid. 1-nitroxyadamantane is dissolved in 93.0-96.0% sulphuric acid containing 0.7-1.0 moles of urea. Methanoic acid or its salt is added in amount of 1.5-2.0 mol per mole of 1-nitroxyadamantane and held at temperature 18-20°C for 4-24 hours. The reaction mass is diluted with water at temperature 90-95°C and held at temperature 80-90°C for 30-40 minutes to complete hydrolysis of the formed 1-nitrourea and 1,3-dinitrourea. Adamantane carboxylic acid is the cooled and filtered. Output of the end product with melting point of 177-180°C is theoretically equal to 90-99%.

EFFECT: design of an efficient method of obtaining 1-adamantane carboxylic acid.

3 cl, 8 ex

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