PL213535B1 - New S-substituted 2-thiorotic acids and the method of obtaining them - Google Patents

Description

Description of the invention

The invention relates to novel compounds useful in the synthesis of 2-thiorotic acid derivatives.

2-thioorotic acid finds application as a potential antimetabolite of orotic acid.

The literature (MA Lea, A. Luke, A. Assad, M. Patel, PA Reddy; International Journal of Biochemistry 24 (9), 1453-1459 (1992)) describes the action of 2-thioorotic acid as an inhibitor of nucleotide metabolism and acid synthesis nucleic acid in liver cancer cells, which inhibits the growth of these cells, and therefore can be used in the treatment of liver cancer.

The use of 2-thiorotic acid as a pharmaceutical is significantly limited due to its very low solubility in both water, organic solvents and fats. The introduction of a substituent on the sulfur atom to the molecule of this compound generally improves its solubility in many organic solvents, e.g. in ethyl alcohol and significantly increases the lipophilicity of the molecule, and thus its affinity for fats, and thus the ability to penetrate inside the cell in a living organism.

Despite the existing practical applications of both 2-thioorotic acid and its derivatives, few such derivatives are known due to the low reactivity of 2-thioorotic acid at room temperature and its susceptibility to decomposition at elevated temperatures in the reaction environment, e.g. . de-thiolation.

The object of the invention was to find compounds which will readily undergo reactions to give 2-thioorotic acid derivatives substituted at the sulfur atom.

The present invention relates to new, S-substituted 2-thioorotic acids of general formula 1:

wherein R is a straight chain ω-bromoalkyl substituent containing from 2 to 10 groups

CH2.

In a second aspect, the invention relates to a process for the preparation of S-substituted 2-thioorotic acids of general formula I in which R is as defined above.

The process according to the invention consists in the reaction of 2-thioorotic acid of formula 2:

with α, ω-dibromoalkanes of general formula 3:

wherein n ranges from 2 to 10 in a solution of a polar organic solvent in the presence of an amount of alkalizing agent used in an amount corresponding to twice the excess over 2-thioorotic acid.

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An underflow of an alkalizing agent can also be used, but it has a negative effect on the yield as some of the 2-thioorotic acid will not dissolve in the reaction medium. An excess of alkalizing agent results in the precipitation of the 2-thiorotic acid salt, which also lowers the yield of the reaction. In view of the stability of the 2-thiorotic acid, it is preferable to carry out the reaction at room temperature.

The reaction is carried out in the presence of alkalizing agents selected from the group: NaOH, KOH, sodium, potassium or calcium carbonates, ammonia water, it is preferable to use sodium hydroxide.

Solvents used as solvents are selected from the group: lower aliphatic alcohols, polyhydric alcohols containing from 2 to 3 carbon atoms, benzyl alcohol, acetonitrile, DMSO, DMF. The use of methanol is particularly preferred.

For a good yield, it is preferable to use an excess of the dibromoalkane, the ratio of acid to alkane being from 1: 1.5 to 1: 5.

After completion of the reaction, the precipitate of the 2-thioorohydic acid salt is separated, and the reaction mixture is then concentrated under reduced pressure with gentle heating (35-40 ° C). The crude product is then precipitated by acidifying the cooled mixture. Due to the instability of the product in a strongly alkaline environment, it is advisable not to exceed the pH value of 10 during the concentration of the solution.

The compounds, which are the subject of the invention, are new, easy-to-obtain derivatives of 2-thioorotic acid, which can be used for further modifications (e.g. allow the use of the alkylthioorotic group as a substituent for other organic molecules), and as biologically active substances - enzyme inhibitors and substances mucoprotective.

The compounds according to the invention are characterized by high reactivity in many substitution reactions due to the presence of a bromine atom at the end of the alkyl chain, which is exchanged for another functional group, and therefore can be used to easily prepare new 2-thiorotic acid derivatives. In particular, they can be used to prepare a wide range of 2-thioorotic acid derivatives that have not been synthesized so far, i.e. the corresponding alcohols, ethers, thiols, sulfides, thiocyanates, azides, etc. and to use them for further reactions according to the reactivity of the groups introduced. functional

The 2-bromoalkylthioorotic acids according to the invention can be used as biologically active agents. The activity of the above compounds was assessed by the in silico method [Stepanchikova A. V., Lagunin A. A., Filimonov D. A., Poroikov V. V .; Prediction of biological activity spectra for substances: Evaluation of diverse sets of drug-like structures; Curr. Med. Chem. 2003, vol. 10, 225-233], from which it was found that the compounds according to the invention may exhibit pharmacological activity. The results of the in silico analysis, ie examples of predicted effects, are summarized in the table below. The value of Pa> 0.7 indicates a very high possibility of a given activity, and Pa> 0.5 - the possibility of the occurrence of a given activity (Pa - probability of activity).

T a b e l a 1

Possibility of biological activity (Pa)

Type of biological activity Relationship AND II-VII Protective for mucous membranes (mucoprotective) 0.510 0.578 Anti-ulcer 0.510 0.578 Inhibiting proline aminopeptidase 0.953 0.928 Protein phosphoenol-pyruvate inhibiting phosphotransferase 0.939 0.910 Threonine aldolase inhibiting 0.906 0.859 Inhibiting (-) - (4S) -limonene synthase 0.906 0.876 Inhibiting (R, R) -butanediol dehydrogenase 0.877 0.826 Inhibiting pitrilysin 0.808 0.736

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The above mentioned Pa values indicate that these compounds can, with a high probability, be inhibitors of enzyme flagella, and thus influence various metabolic processes in the body, as well as have anti-ulcer and protective mucosal properties.

The invention is illustrated by the following examples which do not exhaust all possible uses of the synthesis method according to the invention.

The obtained compounds were characterized by the value of the chromatographic constant Rf (TLC, DC-Alufolien Kieselgel 60 F254, Merck 1.05554; butanol-acetic acid-water mobile phase 5: 2: 3), elemental analysis (Elementar Americas Elementar Analyzer Vario III EL) and spectroscopic parameters UV / Vis (spectrophotometer Specord UV / Vis); IR (KBr measurement camera Pcrkin Elmer M-180), ¹ H NMR (Varian Gemini apparatus VT 300) and MS (Mass Intectra apparatus AMD AMD 402).

P r z k ł a d 1

In a 100 mL round bottom flask 0.344 g of 2-thioorotic acid (2 mmol) was added and 0.1 M methanolic sodium hydroxide (40 mL) was added portionwise with stirring until all of the 2-thioorotic acid was dissolved.

To the resulting clear solution, 1.88 g (10 mmol) of 1,2-dibromoethane was added dropwise and stirring was continued at room temperature for 2 days. During the reaction, the sodium salt of 2-thioorotic acid precipitates from the solution. The reaction is monitored by thin layer chromatography (TLC). After completion of the reaction, the precipitated sodium 2-thioorotate is filtered off, and the filtrate is concentrated on a rotary evaporator at 35-40 ° C water bath to half the original volume. The concentrated reaction mixture is acidified after cooling with 1M hydrochloric acid to a pH of about 1. The precipitate formed is filtered off, washed twice with diethyl ether and air-dried. Crystallization of the obtained solid from methanol gave a colorless product, 2-bromoethylthioorotic acid, mp = 209-214 ° C, yield 45%;

Rf = 0.60 (butanol-acetic acid-water 5: 2: 3);

MS: M ⁺ m / z 278/280;

¹ H NMR (δ, ppm): -13 (COOH); 6.39 (s, 1H, C5-H); 4.71 (t, 2H, Br-CH2); 3.51 (t, 211, CH2-S);

IR (KBr, v, cm ^-1 ): 1680 (C = O acid), 1650 (C = O ketone), 1550 (C5 = C6);

UV / Vis (CH3OH): λ, ηαχ 234.8, Ig ε 4.22.

Elemental analysis:

Calcd%: C 30.12, H 2.53, N 10.04;

Found%: C 30.83, H 2.69, N 10.28.

P r z k ł a d 2

The procedure is as in Example 1, but in place of 1,2-dibromacetate, 0.642 g (4 mmol) of 1,5-dibromopentane. The reaction was carried out for 7 days. After working up the reaction mixture as in Example 1, 2-bromopentylthioorotic acid was obtained in 25% of theory.

Rf = 0.66 (butanol-acetic acid-water 5: 2: 3);

MS: M ⁺ m / z 320/322;

¹ H NMR (δ, ppm): -13 (COOH); 6.33 (s, 1H, C5-H); 3.52 (t, 2H, Br-CH2); 3.18 (t, 2H, CH2-S);

IR (KBr, v, cm ¹ ): 1690 (C = O acid), 1640 (C = O ketone), 1575 (C5 = C6);

UV / Vis (CH3OH): λ, ηαχ 236.0, Ig ε 4.14.

Elemental analysis:

Calcd%: C 37.69, H 4.22, N 8.38;

Found%: C 37.39, H 4.08, N 8.72.

P r z k ł a d 3

The procedure is as in Example 1, but in place of 1,2-dibromacetate, 0.67 g (4 mmol) of 1,6-dibromohexane. The reaction was carried out for 14 days. 2-bromohexylthioorotic acid was obtained in a yield of 37% of theory.

Rf = 0.66 (butanol-acetic acid-water 5: 2: 3);

MS: M ⁺ m / z 334/336;

¹ H NMR (δ, ppm): -13 (COOH); 6.61 (s, 1H, C5-H); 3.52 (t, 2H, Br-CH2); 3.18 (t, 2H, CH2-S);

IR (KBr, v, cm ¹ ): 1690 (C = O acid), 1640 (C = O ketone), 1575 (C5 = C6);

UV / Vis (CH3OH): λ, ηαχ 236.2, Ig ε 4.13.

Elemental analysis:

Calcd (x 1/2 H2O)%: C 38.77, H, N 8.39;

Found%: C 38.35, H 4.54, N 8.13.

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P r z k ł a d 4

The procedure is as in Example 1, but in place of 1,2-dibromoethane, 0.699 g (4 mmol) of 1,7-dibromoheptane. The reaction was carried out for 8 days. 2-bromoheptylthioorotic acid was obtained in 30% of theory.

Rf = 0.66 (butanol-acetic acid-water 5: 2: 3);

MS: M ⁺ m / z 348/350;

¹ H NMR (δ, ppm): -13 (COOH); 6.61 (s, 1H, C5-H); 3.52 (t, 2H, Br-CH2); 3.18 (t, 2H, CH2-S);

IR (KBr, v, cm ¹ ): 1690 (C = O acid), 1640 (C = O ketone), 1575 (C5 = C6);

UV / Vis (CH3OH): Amax 236.2, Ig ε 4.12.

Elemental analysis:

Calcd (x H2O)%: C 38.91, H 4.81, N 7.39;

Found%: C 39.21, H 5.17, N 7.63.

Claims (2)

1. New, S-substituted 2-thioorotic acids of general formula I, in which R is a ω-bromoalkyl substituent, containing in a straight chain from 2 to 10 methylene groups: 2. The method of obtaining new S-substituted 2-thioorotic acids of general formula 1: in which R is a ω-bromoalkyl group containing in a straight chain from 2 to 10 methylene groups, characterized by the reaction of a 2-thioorotic acid of formula 2: with the corresponding α, ω-dibromoalkane of general formula 3: where n = 2-10, in a polar organic solvent, in the presence of an alkalizing agent used in an amount sufficient to completely dissolve the 2-thioorotic acid.