KR830002484B1 - 3" - acylated macrolide antibiotics - Google Patents

Abstract

Macrolide antibiotics I (R3=C2˜C6 alkanoy1; R4=C2˜C5 alkanoy1; R11=C2˜C3 alkanoy1) were ! prepd. Thus, a mixt. of 2'-o-acetylleucomycin A5, pyridine, and trimethylchlorosilane in dichloromethane was stirred at room temp. for an hr. to give 2'-acety1-9-o-trimethylcyllylle- ! ucomycin A5, which was treated with tribenzylamine and acetylchloride in dioxane, and extd. with CHCl3. The CHCl3 layer was reacted with NH3-satd. MeOH, extd. with CHCl3, and refluxed in cold MeOH to give 3,3"-di-o-acety1-9-o-trimethylcyllylleucomycin A5, which was eluted with benzene-acetone soln. to give 3"-o-acetylleucomycin A4.

Description

Process for preparing 3 '' acylated macrolides

The present invention relates to a process for the preparation of novel 3 ''-acylated macrolide antibiotics of the general formula (1a).

Wherein R ₃ is an alkanoyl group (C ₂ -C ₆ ),

R ₄ is an alkanoyl group (C ₂ -C ₅ ),

R ₁₁ is an alkanoyl group (C ₂ -C ₃ ).

Also useful are salts of the compounds, where salt means a physiologically acceptable salt. Examples of such salts are inorganic salts such as hydrogen chloride, sulfate or phosphate and organic salts such as acetate, propionate, tartrate, citrate, succinate, aspartate and glutamate.

Other nontoxic salts may also be included.

The novel compound (1a) of the present invention is a conventional 16-demand macrolide such as leucommycin group antibiotics including irradiated mycin, SF-837 group antibiotics, YL-704 group antibiotics, and epinomycin grium antibiotics. It has improved antimicrobial activity against susceptible or resistant strains compared to antibiotics. In particular, the compound is very effective against strains resistant to other macrolide antibiotics such as oleamycin, erythromycin, carbomycin and spiramycin. Moreover, a series of blood levels increases because deacylation at the 4 '' position, which is one of the reasons for inactivation of 16-demiver macrolide antibiotics, cannot easily occur. In addition, since the strong and persistent bitter taste, which is a general characteristic of macrolide antibiotics, is reduced, syrups for infants having difficulty in pill administration may be preferably prepared. As a result, the compound (1a) of the present invention is expected to exhibit an excellent clinical infectious disease treatment effect. In the nomenclature of the compounds of the invention, this is influenced by substituents at the 3-position of the general formula (1a) or substituents at the 3 '' and 4 '' positions.

Thus, when the 3 '' position is acylated or when the original acyl group at the 4 '' position is not transposed at the 3 '' position as an acyl arrangement, the nomenclature is known as represented by the following structural formula (2) Is based on antibiotics.

Wherein R ₁ represents a hydrogen atom or an alkanoyl (C ₂ -C ₃ ) group,

R ₄ is an alkanoyl (C ₂ -C ₅ ) group.

The compounds represented by the above formula are listed as follows.

Antibiotics of formula (2) wherein R ₁ is a hydrogen atom have hydroxyl groups at the 3, 9, 2 'and 3''positions, and 9, 2' and 3 '' positions when R ₁ is an acetyl or propionyl group Has a hydroxyl group.

In these groups, hydroxyl groups in the 3, 9 and 2 'positions are easily acylated and therefore many acylated derivatives therefrom have been reported. However, hydroxyl groups at the 3 '' position have been reported to be inactive.

In recent years, derivatives in which hydroxyl groups at the 3 '' position are acylated have been reported. (See Japanese Patent Publication Nos. 49-124087 and 51-26887.) These compounds reported are essentially those having a propionyl group at the 3 position and an acyl group at the 9 position.

However, in order to produce derivatives (hereinafter referred to as 3 ''-acylated derivatives) in which the 3 '' position is acylated while having at least one hydroxyl group in the 3 and 9 positions, only the 3 '' position of the antibiotics previously known In order to introduce an acyl group, since there is a very active hydroxyl group at a position other than the 3 '' position, acylation by the conventional acylation method was impossible.

The inventors have found that a protecting group other than 3 ", in particular 3 and / or 9, can be easily removed without 3 " -acylating after the 3 " hydroxyl group is acylated. Found out that it could be protected.

Accordingly, it is an object of the present invention to provide a method for preparing a novel macrolide antibiotic represented by the general formula (1a).

Another object of the present invention is to provide an antibiotic having high blood levels and high activity against sensitive or resistant strains when taken.

The novel 3 ''-acylated macrolide antibiotics of general formula (1a) according to the invention are prepared as follows.

Wherein R ₁ and R ₄ are the same as defined above,

R ₅₃ is silyl,

R ₆ is a hydrogen atom or an alkanoyl group (C ₂ -C ₄ ).

Compounds of the following general formulas (4a) and (4b) by acylating by heating together with aliphatic carboxylic acid halides (C ₂ -C ₆ ) in the presence of the above-mentioned compound of formula (3 ') and an inert organic solvent and tertiary organic amine Obtain a mixture of

Wherein R ₃ , R ₄ , R ₅₃ , and R ₁₁ are as defined above,

R ₈ is alkanoyl (C ₂ -C ₅ ) or is the same as R ₃ .

Wherein R ₃ , R ₄ , R ₅₃ , R ₈ and R ₁₁ are as previously defined. The mixture is then heated in an aqueous lower alkanol, which may contain a base, to remove the silyl groups and the acyl groups at the 18 and 2 'positions, or by treatment with an aqueous lower alkanol without heating the mixture in the presence of a base. Remove the acyl group at position 18 and then heat it in a methanol which may contain water to remove the 2 'position, or treat the mixture with ammonia containing methanol to remove the acyl group at position 18 and then lower aqueous alkanol Heat in to remove the silyl groups and acyl groups in the 2 'position, or treat the mixture with methanol containing ammonia to remove the acyl groups in position 18 and then heat in the methanol to remove the acyl groups in the 2' position and then Treatment with acid to remove the silyl group yields 3 ''-acylated macrolide antibiotics of general formula (Ia).

Compound (3 ') is a compound in which a protecting group is introduced at position 9 of the antibiotic of Formula (2) to prevent acylation of hydroxyl group at position 9 in the 3' '-acylation step. This protective group is a group that can be selectively removed without breaking the chemical structure after 3 ''-acylation, for example a silyl group.

Introduction of the silyl group can be accomplished by treatment with a suitable silylation reagent such as tri-substituted halogeno silane or hexa-substituted silazane. Silylation reagents include, for example, silanes such as trimethylchloro silane and silazanes such as hexamethyl silazane. Any silylation reagent can be used as long as the silyl group introduced cannot be removed by water.

The silylation reaction is carried out in an inert organic solvent such as dichloromethane, chloroform and methyl isobutyl ketone at room temperature or lower. The amount of silylation reagent used is about 1-1.8 molar equivalents. In the silylation reaction with tri-substituted halogenosilanes, tertiary organic amines are used as dehydrohalogen reagents. Examples thereof include pyridine, quinoline, N-methylmorpholine, dimethylaniline and the like. The silylated product of formula (3 ') can be obtained by pouring the reaction mixture into water and then extracting it with a suitable organic solvent which does not mix with water. The silyl group of compound (3 ') is stable to water and cannot be removed in the presence of water.

As already explained, in the protection of the hydroxyl position at the 9 position of the antibiotic (2), the hydroxyl group at the 2 'position can be arbitrarily protected by a protecting group, which is a C ₂ -C ₄ egg such as an acetyl group. It is a canoyl group. 2 'acetylation can be carried out by the procedure described in Japanese Patent Publication No. 53-7434.

Compound (3 ') is 3' '-acylated with aliphatic carboxylic acid halides.

The reaction is carried out by heating in the presence of a tertiary organic amine in an inert organic solvent. Inert organic solvents are acetone, methyl ethyl ketone, ethyl acetate, dimethoxyethane, tetrahydrofuran, dioxane, benzene or toluene, and the tertiary organic amines are pyridine, picoline or collidine. Meanwhile, other well-known organic amines such as triethylamine, dimethylaniline, tribenzylamine, N-methylpiperidine, N-methylmorpholine, quinoline or isoquinoline may be used.

Aliphatic carboxylic acid halides used are, for example, C ₂ -C ₆ aliphatic carboxylic acid halides, such as acetyl chloride, propionyl chloride, butyryl chloride or caproyl chloride. The heating reaction temperature is 50-120 ° C. and the reaction time may vary since it depends on the reaction temperature.

Reaction termination is determined in the range of 1-50 hours, and the reaction process is detected by silica gel thin layer chromatography.

The acylation reaction at the 3 '' hydroxy group of position on the acylation of 1 and 178 and the position _{^{[- 17 CH 2 - 18 CHO}} ] instead of [- ^{17 18} CH = CHOR _3], a phosphorus compound is produced as a by-product. The amount of the aliphatic carboxylic acid halide should be changed according to the number of hydroxyl groups to be acylated, since the hydroxyl group in the 3 position and the hydroxyl group or acylated in the unprotected 2 'position.

In the reaction of compound (3 ') wherein R ₁ is a hydrogen atom, different acyl groups are introduced at the 3 and 3''positions. That is, in order to obtain a compound (4a) having an acyl group having different R ₁₁ and R ₃ , an acyl group such as an acetyl group or a propionyl group is first introduced into the 3-position hydroxyl group of the compound (3 '), and then the 3''position is not. It is a true story.

The mixture of the compounds (4a) and (4b) thus obtained is adjusted to pH 8-10 in water and precipitated, or, if the reaction solvent is an organic solvent which is not mixed with water, it is poured into water and the pH is adjusted to 8-10. Then separated by extraction with an organic solvent that does not mix with water.

Purification is carried out by chromatography using silica gel, activated alumina or sorbent resin together with benzene-acetone and the like as eluent.

The removal of the 9, 18 and 2 '' position protecting groups of the mixture of compounds (4a) and (4b) depends on the protecting group at the 9 position.

As described above, the protective groups in the 9, 18 and 2 'positions can be removed according to the following methods. The 9 position is a silyl group and the 18 and 2 'positions are acyl groups.

a) Removal of the silyl groups and acyl groups at the 18 and 2 ′ positions by heating in aqueous lower alkanols, which may include bases.

b) Treatment with aqueous base alkanol in the presence of base without heating to remove silyl groups and acyl groups at position 18, and heating in methanol, which may contain water, to remove acyl groups at position 2 '.

c) Treatment with methanol containing ammonia to remove the acyl group at position 18 and heating in aqueous lower alkanol to remove the silyl group and acyl group at the 2 'position.

d) Treatment with ammonia containing ammonia to remove acyl groups at position 18 and heating with methanol to treat acyl groups at position 2 'with aqueous acids to remove silyl groups.

The lower alkanols in the stomach are preferably methanol or ethanol.

In the above (a) and (b), tertiary organic amines, basic carbonates or basic resins can be used. Heating can be done by convection the organic solvent. In (b), unheated conditions or unspecified temperature conditions mean room temperature or below. Termination of the reaction can be detected by silica gel thin film chromatography.

Separation of compound (1a) from the reaction mixture can be carried out by well-known separation and purification methods such as concentration, extraction, washing, mobile extraction and recrystallization, chromatography using silica gel, activated alumina, adsorbent resin or ion exchange resin. Can be.

The antimicrobial spectra of compound (1a) of the present invention are shown in the following table. These data show that Compound (1a) exhibits improved antimacrobial activity against resistant strains as well as sensitive strains compared to conventional antibiotics.

Minimum Inhibitory Concentration (MIC)

ug / ml

^* Clinically isolated (macrolide antibody A-group strain)

erythromycin, oleendomycin, 16-16 ber macrolide antibodies, broth dilution in inoculum size 10 ₈ / ml

^* TM = leucomycin

The present invention will be described in detail with the following examples.

Unless otherwise specified, the Rf values of the examples are measured by the following thin film chromatography.

Carrier: Silica gel 60 (art. 5721, Merck Co.)

Developer:

A: n-hexane-benzene-acetone-ethyl acetate-methanol (90: 80: 25: 60: 30)

B: benzene-acetone (3: 1)

C: benzene acetone (5: 1)

Example 1

3 ''-0-acetylleucomycin A ₄ (3, 3 ''-di-0-acetylleucomycin A ₅ ):

Dry pyridine (6 ml) and trimethylchloro silane (5.69 ml) are added to 2'-0-acetylleucomycin A ₅ (30 g) dissolved in dry dichloromethane (150 ml) under ice cooling and stirred at room temperature for 1 hour. The reaction mixture was washed with 0.1N hydrochloric acid, water and 3% aqueous ammonia, then dehydrated with anhydrous magnesium sulfate and dried in vacuo to give coarse 2'-acetyl-9-0-trimethylsilylleucomycin A ₅ (30.2 g). . Dissolve the above in dry dioxane (50ml), add tribenzylamine (113g) and acetyl chloride (25ml) and stir at 80 ° C for 40 hours.

The reaction mixture is poured into water (1 l), adjusted to oH with ammonia water to 9.5, and extracted with chloroform (500 ml).

The extract is dehydrated with anhydrous magnesium sulfate and dried in vacuo. Add ammonia saturated ethanol solution (50 ml) to the residue and stir at half temperature for 2 hours.

The reaction mixture is poured into water (1.5 l) and extracted with chloroform (500 ml). The chloroform layer is dehydrated with anhydrous magnesium sulfate and dried in vacuo. The residue is dissolved in cold methanol (200 ml) and filtered off insoluble tribenzyl amine.

The filtrate was heated to reflux for 20 hours and dried to afford coarse 3, 3 ''-di-0-acetyl-9-0-trimethylsilylleucomycin A ₅ . This material is dissolved in acetic acid-tetrahydrofuran-water (3: 1: 1: 1) (125 ml) and stirred at room temperature for 2 hours.

Chloroform (500 ml) was added to the reaction mixture and washed with 3% ammonia water. The chloroform layer is dehydrated with anhydrous magnesium sulfate and dried in vacuo to give coarse 3, 3 ''-di-0-acetylleucomycin A. (29.8g) This material was dissolved in a small amount of benzene, chromatographed on a silica gel tube with benzene-acetone (10: 1-8: 1-6: 1) to collect the part showing Rf _A = 0.58 and dried in vacuo. Purified product is obtained.

(21.2g, yield: 67.2%)

Rf _A = 0.58 Rf _B = 0.15

Mass (m / e): 855 (M ⁺ ), 796 (M ⁺ -59), 768 (M ⁺ -87)

Example 2

3 ''-acetyl-SF-837

Acetic anhydride (2.5 ml) is added to SF-837 material (4.0 g) dissolved in acetone (40 ml) and stirred at room temperature for 3 hours. The reaction mixture was added to ice water (400 ml), the pH was adjusted to 8.5 with 7% ammonia water, and extracted once with benzene (200 ml). Dehydration of the benzene layer with anhydrous magnesium sulfate and vacuum drying yielded 2'-0-acetyl-SF-837 material (4.15 g).

Yield: 98.6%

Rf _A = 0.66 Rf _B = 0.33

In Example 1, using 3 g of 2'-0-acetyl-SF-837 instead of 2'-0-acetyl leucomycin A ₅ and reacting by controlling the amount of the other reagents at the same ratio, the target 3 '' -0-acetyl-SF-837 (2.2 g) is obtained.

Rf _A = 0.58 Rf _B = 0.22

Mass (m / e): 855 (M ⁺ ), 796 (M ⁺ -59), 782 (M ⁺ -73)

NMR (CDCl ₃ , 100 MHz): 1.43 (3``-CH ₃ ), 2.01 (3 ''-A _C )

2.57 (3``-N (CH ₃ ) ₂ ), 3.58 (4-OCH ₃ ), 9.72 (CHO) ppm

Claims (1)

Compounds of formula (3 ′) are heated with aliphatic carboxylic acid halides (C ₂ -C ₆ ) in the presence of an inert organic solvent and a tertiary organic amine to be asymmetric to give a mixture of compounds of formulas (4a) and (4b) The mixture is then heated in aqueous lower alkanol, which may contain a base, to remove the silyl groups and acyl groups at the 18 and 2 'positions, or treated with aqueous lower alkanol without heating the mixture in the presence of a base. And the acyl group at position 18 and then heated in a methanol containing water to remove the 2 'position, or the mixture is treated with ammol containing ammonia to remove the acyl group at position 18 followed by an aqueous lower alka. Heat in the furnace to remove the silyl groups and acyl groups in the 2 'position, or treat the mixture with methanol containing ammonia to remove the acyl groups in position 18 and then A method of preparing a 3 ''-acylated macrolide antibiotic of general formula (1a) by heating in methanol to remove acyl groups at the 2 'position, followed by treatment with an aqueous acid to remove the silyl groups.

Wherein R ₁₁ is an alkanoyl group (C ₂ -C ₃ ), R ₃ is an alkanoyl group (C ₂ -C ₆ ), and R ₄ is an alkanoyl group (C ₂ -C ₅ ).

Wherein R ₁ is a hydrogen atom or an alkanoyl group (C ₂ -C ₃ ), R ₄ is the same as defined above, R ₅₃ is a silyl group, R ₆ is a hydrogen atom or an alkanoyl group (C ₂ -C ₄ )being.

Wherein R ₃ , R ₄ , R ₅₃ and R ₁₁ are as previously defined and R ₈ is alkanoyl (C ₂ -C ₅ ) or equal to R ₃ .

Wherein R ₃ , R ₄ , R ₅₃ , R ₈ and R ₁₁ are as previously defined.