JPH0142276B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to novel 19-deformyl-23-demysinoyl-23-O-substituted carbamoyl desmycosine derivatives and methods for their production. More specifically, the present invention provides the formula (In the formula, R ₁ is a phenyl group that may have a substituent, R ₂ is a hydrogen atom or a lower alkyl group, R ₃
represents a hydrogen atom or a lower alkyl group) or a salt thereof. Moreover, the present invention also provides the formula (In the formula, R ₄ represents a protecting group for the hydroxyl group) is reacted with 1,1'-carbonyldiimidazole in an inert organic solvent to convert the hydroxyl group at position 23 into an imidazolide, and the resulting imidazolide is converted into an imidazolide. formula (In the formula, R ₁ , R ₂ and R ₃ mean the same groups as above) are reacted under heating, and then the protecting groups of the hydroxyl groups at the 2' and 4' positions are removed. This is a method for producing the characteristic compound [1] or a salt thereof. The above salts are pharmaceutically acceptable salts.
Such suitable salts include salts with inorganic acids such as hydrochloric, sulfuric, and phosphoric acids, and salts with organic acids such as acetic, propionic, tartaric, citric, succinic, malic, aspartic, and glutamic acids. is included. Other non-toxic salts are also included. The above-mentioned novel compound [1] shows strong antibacterial activity against Gram-positive bacteria and Gram-positive bacteria, and in particular shows much stronger antibacterial activity against Gram-positive bacteria than diyosamicin and tylosin, and is stable in vivo. Therefore, it is an antibacterial agent that is expected to have excellent clinical efficacy in treating infections. It is also useful as a therapeutic agent for animal infections, and as a feed additive for preventing infection or promoting growth. Compound [3] used in the present invention is 19-deformyl-23-demycinosyl desmycosine, that is, the formula The hydroxyl groups at the 2' and 4' positions of the compound represented by are protected with appropriate protecting groups. The above starting material [5] is 23-demycinosyldesmycosin [Tetrahedron Letters, 4737
(1970)] with (C ₆ H ₅ ) ₃ P] ₃ RhCl under heating in an inert organic solvent (JP-A No. 56-55399). Suitable protecting groups mentioned above include lower alkanoyl groups such as acetyl, propionyl, and butyryl;
Examples include halogenated acetyl groups such as chloroacetyl, dichloroacetyl, trichloroacetyl, and trifluoroacetyl, with acetyl groups being particularly preferred. The protection of the 2'- and 4'-position hydroxyl groups of compound [5] with acetyl groups is carried out by reacting compound [5] with acetic anhydride in an inert organic solvent. Preferred inert organic solvents include dichloromethane, chloroform, dichloroethane, acetone, and the like. The reaction proceeds satisfactorily at room temperature. Since the progress of the reaction can be monitored by thin layer chromatography (TLC) using silica gel or the like, high performance liquid chromatography (HPLC), etc., the reaction can be appropriately terminated after waiting for the disappearance of the compound [5]. To collect the reaction product [3] from the reaction solution, water is added to the reaction solution, and the mixture is treated with a non-hydrophilic organic solvent such as chloroform, dichloromethane, methyl isobutyl ketone, ethyl acetate, butyl acetate, etc. under an alkaline pH of 8 to 9.5. This is done by extracting. If further purification is required, an appropriate solvent such as benzene-acetone solvent,
It can be separated and purified by column chromatography eluting with a chloroform-methanol solvent or the like. In order to O-substituted carbamoylate the hydroxyl group at position 23 of compound [3], the hydroxyl group is first converted into an imidazolide. Compound [3] is reacted with 1,1'-carbonyldiimidazole in an inert organic solvent. Just let it happen. Examples of the inert organic solvent include halogenated hydrocarbon solvents such as dichloromethane, chloroform, and dichloroethane. The reaction is usually carried out at room temperature. Since the progress of the reaction can be monitored by thin layer chromatography (TLC) using silica gel or the like, high performance liquid chromatography (HPLC), etc., the reaction can be appropriately terminated after waiting for the disappearance of compound [3]. The imidazolide obtained by the above reaction may be directly used in the next reaction without being isolated from the reaction solution, that is, the reaction with amine [4], or may be used after isolation. When isolating the imidazolide, pour the reaction solution into water and adjust the pH of the aqueous layer to 8-8.
After adjusting to 9.5, an extraction operation is performed and the solvent is distilled off from the organic solvent layer. Amine directly without isolating the imidazolide [4]
When used in the reaction with compound [3] and 1,
For the reaction with 1'-carbonylimidazole, it is preferable to use a high boiling point organic solvent such as dichloroethane. The amine [4] includes benzylamine,
α-Lower alkyl-benzylamine, e.g. α-
Methylbenzylamine, α-ethylbenzylamine, N-lower alkyl-benzylamine, e.g. N-methyl-benzylamine, N-ethyl-benzylamine, N-lower alkyl-α-lower alkyl-benzylamine, e.g. N-methyl -α-methylbenzylamine, N-methyl-α-ethylbenzylamine, N-ethyl-α-methylbenzylamine, and the like. The reaction between the imidazolide and the amine [4] is carried out in an inert organic solvent under heating. Examples of inert organic solvents include dichloroethane, benzene, toluene, dioxane, and the like. Heating is carried out at a temperature at or below the boiling point of the organic solvent, usually about 70 to 90°C. The 23-O-substituted carbamoyl compound thus obtained, that is, the formula To collect the compound represented by (wherein R ₁ , R ₂ , R ₃ and R ₄ mean the same groups as above) from the reaction solution, add water to the reaction solution, and , by extraction with a non-hydrophilic organic solvent such as chloroform, dichloromethane, dichloroethane, methyl isobutyl ketone, ethyl acetate, butyl acetate, etc. If further purification is required, purification is performed by column chromatography using an adsorbent such as silica gel, activated alumina, or adsorption resin and eluting with an appropriate solvent such as a benzene-acetone solvent or a chloroform-methanol solvent. be able to. Next, the protective groups for the hydroxyl groups at the 2' and 4' positions of reaction product [2], especially the acetyl group, are eliminated, and this elimination is done by heating in a lower alcohol that may contain water. This is done by processing. Examples of lower alcohols include methanol and ethanol, with methanol being particularly preferred.
The above-mentioned elimination reaction can be monitored by TLC, HPLC, etc., and the reaction can be appropriately terminated after waiting for the disappearance of the reaction product [2]. In order to collect the thus obtained compound [1] from the reaction solution, the lower alcohol is distilled off, and a non-hydrophilic organic solvent is added under alkaline pH 8 to 9.5.
For example, this is carried out by extraction with chloroform, dichloromethane, dichloroethane, methylisobutyrtone, ethyl acetate, butyl acetate, or the like. If further purification is required, it can be purified by means of chromatography using an adsorbent such as silica gel, activated alumina, or adsorption resin. In the present invention, when R ₃ is a hydrogen atom, the reaction product [2] in that case can also be produced by another method. That is, compound [3] is reacted with bis(tri-lower alkyltin) oxide under heating in an inert organic solvent to convert the hydroxyl group at position 23 into tri-lower alkylstanylation, and the resulting reaction product has the formula (In the formula, R ₁ and R ₂ mean the same groups as above)
It is obtained by reacting an isocyanate represented by: As the above-mentioned inert organic solvent, benzene-based solvents such as benzene and toluene are preferred. As bis(tri-lower alkyltin) oxide,
Particularly preferred is bis(tributyltin) oxide. Heating is carried out at a temperature at or below the boiling point of the solvent, usually within the range of 80 to 110°C. In the above reaction, water is produced, so
It is convenient to carry out the reaction by adding an insoluble dehydrating agent to the reaction solvent, for example a molecular sieve. Compound [5] is obtained by O-substituted carbamoylation of the obtained tri-lower alkyl stannyl compound. In this carbamoylation, if the dehydrating agent used is separated from the reaction solution, the tri-lower alkyl stannyl compound can be converted to O-substituted carbamoylation. The reaction is carried out by directly adding the isocyanate represented by the formula [6] to the reaction solution without isolation or purification. Examples of the isocyanate [6] include benzyl isocyanate and α-lower alkylbenzylisocyanate, such as α-methylbenzylisocyanate and α-ethylbenzylisocyanate. These phenyl groups may be substituted with a substituent in the same manner as described above. The reaction between the tri-lower alkyl stannyl compound and the isocyanate [6] usually proceeds satisfactorily at room temperature. Since the reaction can be monitored by TLC, HPLC, etc., the reaction can be appropriately terminated after waiting for the disappearance of the tri-lower alkyl stannyl compound. The reaction product [5] thus obtained can be separated and purified from the reaction solution in the same manner as described above. Next, the results of measuring the minimum inhibitory concentration (MIC) of the target compound [1] of the present invention for microbial growth are shown in the following table.

[Table] Next, production examples of the present invention will be specifically explained with reference to reference examples and examples. Note that Rf values in Reference Examples and Examples are for TLC using the following carrier and developing solvent unless otherwise specified.
It was measured by. Carrier: DC-Fertigplatten Kiesel manufactured by Merck & Co.
gel60F ₂₅₄ Art5715 Developing solvent a; Chloroform-methanol (20:1) b; Chloroform-methanol-aqueous ammonia (150:10:1) c; Hexane-benzene-acetyl-ethyl acetate-methanol (90:80:25:60 :30) Reference example 1 2',4'-di-O-acetyl-19-deformyl-
23-Demycinosyldesmycosine 1.11g (1.95mmol) of 19-deformyl-23-demysinosyldesmycosine was added to 5.5g of dichloromethane.
ml and add 0.92 ml (9.7 mmol) of acetic anhydride to this.
was added and stirred at room temperature for 1.5 hours. After pouring the reaction solution into ice water and adjusting the pH to 9 with 7% aqueous ammonia,
Extracted three times with 20 ml of chloroform. The chloroform layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to obtain a powder of crude 2',4'-di-O-acetyl-19-deformyl-23-demycinosyl desmycocin. Yield: 1.16g (91% yield). This was dissolved in as little chloroform as possible, charged to a column containing 40 g of silica gel, and purified by chromatography using an eluent of chloroform-methanol (150:1) to obtain 475 mg of a purified product. TLC; Rf _a =0.39 Example 1 19-deformyl-23-demysinoyl-23-O
-(N-methyl-benzylcarbamoyl)-desmycosine 2',4'-di-O-acetyl-19-deformyl-
23-Demycinosyl desmycocin 176.1mg
(0.27 mmol) and 52.4 mg (0.32 mmol) of 1,1'-carbonyldiimidazole in dichloroethane.
The solution was dissolved in 2.6 ml and stirred at 50°C for 1.5 hours. The reaction solution was poured into ice water, and the pH of the aqueous layer was adjusted to 2 to 3 with 1N hydrochloric acid, followed by extraction with 20 ml of chloroform.
Water was added to the chloroform layer, the pH of the aqueous layer was adjusted to 9 with 7% aqueous ammonia, and the layer was washed. The chloroform layer was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give crude 2',4'-di-O-acetyl-19-deformyl-23-demycinosyl-23-O-(imidazol-1-yl)carbonyl-desmycosine. 192.3mg of powder was obtained. TLC; Rf _a =0.61 23-O-(imidazol-1-yl) obtained above
Carbonyl compound and N-methylbenzyl 0.066ml (1.5
equivalent amount) was dissolved in 2.3 ml of dichloroethane and stirred at 70°C overnight. Pour the reaction solution into ice water and reduce the aqueous layer to 1N.
The pH was adjusted to 2-3 with hydrochloric acid, and 20 ml of chloroform was added for extraction. Water was added to the chloroform layer, and the aqueous layer was adjusted to pH 9 with 7% ammonia and washed.
The chloroform layer was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by preparative silica gel (Merck & Co., Ltd. Art5717, 20 x 20 cm, 1 sheet) thin layer chromatography using a developing solvent of hexane-benzene-acetone-ethyl acetate-methanol (90:80:25:60:30). Purified. Rf _c = approx. 0.8
After scraping off the nearby spots and eluting with chloroform-methanol (1:1), the eluate was dried under reduced pressure to give 2',4'-di-O-acetyl-19-deformyl-23-demycinosyl-23-O. 120.7 mg of powder of -(N-methyl-benzylcarbamoyl)-desmycosin was obtained. TLC; Rf _c = 0.83 110.7 mg of the 23-O-(N-methyl-benzylcarbamoyl compound obtained above was dissolved in 5 ml of methanol,
Stirred at 55°C overnight. The reaction solution was concentrated under reduced pressure, the residue was dissolved in 50 ml of chloroform, and after adding water,
The pH was adjusted to 9 with % ammonia water and washed. After drying the chloroform layer with anhydrous magnesium sulfate,
The mixture was dried under reduced pressure to obtain a powder of 19-deformyl-23-demycinosyl-23-O-(N-methyl-benzylcarbamoyl)-desmycosin. Yield 95.9mg. TLC; Rf _b = 0.60 NMR (CDCl ₃ ) δ ^TMS _ppn ; 1.78 (br.s., 3H, CH ₃ −
12), 2.50 (s., 6H, (CH ₃ ) ₂ N), 2.82, 2.93 (each
s., total 3H, N- _CH3 ), 4.22(d., 2H, _CH2-
23) 4.29 (d., 1H, H-1'), 4.45 (br.s., 3H, -
_CH2C6H5 ), 4.7-5.2 (br.1H _{, H} -15), 5.65,
5.77 (each br.d., total 1H, H-13), 6.26 (br.d.,
1H, H-10), 7.3-7.4 (6H, -C ₆ H ₅ , H-11) MS (CI); 718 (NH ⁺ ), 174 As a result of NMR, this compound has syn and anti isomerism in the carbamoyl moiety. It was confirmed that it was a mixture of bodies.

Claims (1)

[Claims] 1 formula (In the formula, R ₁ is a phenyl group, R ₂ is a hydrogen atom or a lower alkyl group, R ₃ is a hydrogen atom or a lower alkyl group, and R ₃ is a hydrogen atom or a lower alkyl group) or a salt thereof . 2 19-deformyl-23-demycinosyl-23-
O-benzylcarbamoyl desmycocin or
19-deformyl-23-demycinosyl-23-O-
The compound according to claim 1, which is (N-methylbenzylcarbamoyl)-desmycosine, or a salt thereof. 3 formulas (In the formula, R ₄ represents a protecting group for the hydroxyl group) is reacted with 1,1'-carbonyldiimidazole in an inert organic solvent to convert the hydroxyl group at position 23 into an imidazolide, and the resulting imidazolide expression (In the formula, R ₁ is a phenyl group, R ₂ is a hydrogen atom or a lower alkyl group, and R ₃ is a hydrogen atom or a lower alkyl group) is reacted under heating, and then the 2′- and 4′-positions are reacted. A formula characterized by removing the protecting group of the hydroxyl group of A method for producing a compound represented by the formula (wherein R ₁ , R ₂ and R ₃ mean the same groups as above) or a salt thereof. 4. The production method according to claim 3, wherein the hydroxyl protecting group is a lower alkanoyl group. 5. The production method according to claim 4, wherein the lower alkanoyl group is an acetyl group.