Urea and thiourea derivatives of antibiotic glycopeptides

Abstract: The present invention is directed to N LEU -carbamoyl and thiocarbamoyl derivatives of A82846B and N DISACC variations thereof. These derivatives are useful as antibacterials and also as starting materials from which further antibacterial compounds are prepared.

Description: The present invention is directed to N LEU -carbamoyl and thiocarbamoyl derivatives of A82846B and N DISACC variations thereof. These derivatives are useful as antibacterials and also as starting materials from which further antibacterial compounds are prepared. DETAILED DESCRIPTION OF THE INVENTION EP-A-0435503 (Eli Lilly and Company, 3 July 1991), concerns compounds width an N-alkyl or N-acylmoeitz on the N-methylleucine. The present invention is directed to compounds of the formula wherein R 1 represents O or S; R 2 represents alkyl of C 1 -C 10 , phenyl, naphthyl, or phenyl substituted by one or two substituents, each of which is independently halo, loweralkyl of C 1 -C 4 , loweralkoxy of C 1 -C 4 , benzyloxy, nitro, or wherein each R 2a is independently loweralkyl of C 1 -C 4 ; and R 3 represents hydrogen or -CH 2 -R 3a wherein R 3a represents alkyl of C 1 -C 11 , alkyl of C 1 -C 11 -R 4 , or R 4 -(0 (0 or 1) -R 4 ) 0 or 1' wherein each R 4 is independently phenyl or phenyl substituted by one or two substituents, each of which is independently halo, loweralkyl of C 1 -C 4 , loweralkoxy of C 1 -C 4 , or loweralkylthio of C 1 -C 4 , and pharmaceutically acceptable salts thereof. The compounds of the present invention are prepared by reacting a parent glycopeptide of the formula wherein R 3 is as defined above, with an isocyanate or isothiocyanate of the formula R 1 CN-R 2 , wherein R 1 and R 2 are as defined above. This is the first step of the so-called Edman degradation, which is a two-step process for the cleavage of the N-terminal residue of a peptide or protein. The reaction to prepare the present compounds is carried out in a polar solvent, such as water, in the presence of an organic base, such as pyridine. Generally the reaction is carried out at a temperature of about 15°C to about 35°C for one to five hours. The reaction is preferably carried out at a temperature from about 25°C to 30°C for one to two hours, in water with pyridine as the base. The reaction consumes equimolar amounts of the reactants but a slight excess of the isocyanate or isothiocyanate is preferred. The product is separated and purified if desired in conventional procedures. When it is desired, a salt can be prepared in standard procedures. The following examples illustrate the preparation of the compounds of the present invention. Preparation of Compound of Example 22 N DISACC -(p-(p-Chlorophenyl)benzyl)A82846B trihydrochloride (100.0 mg, 0.0526 mmol) was dissolved in 10 ml H 2 O - pyridine (1:1 v/v) and treated with phenyl isothiocyanate (0.010 ml, 0.083 mmol). The resulting mixture was stirred at room temperature for 1 hour at which time HPLC analysis indicated complete consumption of the starting material. The reaction mixture was concentrated in vacuo and the crude product was purified by preparative HPLC to give 76.6 mg (76% yield) of N LEU -(phenylthiocarbamoyl)-N DISACC -(p-(p-chlorophenyl)benzyl)A82846B. FAB-MS: calc. For C 93 H 102 Cl 3 N 11 O 26 S 1925.5, obtained 1928.5 (M+3). Preparation of Compound of Example 23 A82846B triacetate (270 mg, 0.157 mmol) was dissolved in 30 ml H 2 O - pyridine (1:1 v/v) and treated with phenyl isocyanate (0.030 ml, 0.277 mmol). The resulting mixture was stirred at room temperature for 1 hour at which time HPLC analysis indicated complete consumption for the starting material. The reaction mixture was concentrated in vacuo and the crude product was purified by preparative HPLC to give 62.5 mg (23% yield) of N LEU -(phenylcarbamoyl)-A82846B. FAB-MS: Calc. For C 80 H 93 Cl 2 N 11 O 27 1709.6, obtained 1712.1 (M+3). The HPLC procedures reported in these examples were as follows: Analytical: Reactions were monitored by analytical HPLC using a Waters C 18 µBondapak or Novapak C 18 column (3.9x300 mm) and UV detection at 280 nm. Elution was accomplished with a linear gradient of 5% CH 3 CN - 95% buffer to 80% CH 3 CN - 20% buffer over 30 minutes. The buffer used was 0.5% triethylamine in water, adjusted to pH 3 with H 3 PO 4 . Preparative: Crude reaction mixtures were purified by preparative HPLC using a Waters C 18 Nova-Pak column (40x300 mm) and UV detection at 280 nm. Elution was accomplished with a linear gradient of 5% CH 3 CN - 95% buffer to 80% CH 3 CN - 20% buffer over 30 minutes. The buffer used was 0.5% triethylamine in water, adjusted to pH 3 with H 3 PO 4 . The desired fractions were subsequently desalted with a Waters C 18 Sep-Pak (35 cc) followed by lyophilization. Compounds were desalted as follows. A Waters Sep-Pak cartridge was pre-wet with methanol (2-3 column volumes) then conditioned with water (2-3 column volumes). The sample, dissolved in a minimum volume of water, was loaded onto the Sep-Pak column which was then washed with water (2-3 column volumes) to remove the unwanted salts. The product was then eluted with an appropriate solvent system, typically 1:1 CH 3 CN/H 2 O, CH3CN, and/or methanol. The organic solvent component was removed in vacuo and the resulting aqueous solution lyophilized to give the final product. Representative compounds of the present invention are listed in the following table: Ex # Name FAB-MS M+X Analytical HPLC, min 1 N LEU (PHENYLTHIOCARBAMOYL) A82846B 1728.5 3 18.2 2 N LEU -(PHENYLTHIOCARBAMOYL)-N DISACC -(p-CHLOROBENZYL)A82846B 1852.3 3 21.4 3 N LEU -(PHENYLTHIOCARBAMOYL)-N DISACC -(p-PHENOXYBENZYL)- A82846B 1911.0 3 23.6 4 N LEU -(PHENYLTHIOCARBAMOYL)-N DISACC -(p-PHENYLBENZYL) A82846B 1894.5 3 23.2 5 N LEU -(1-NAPHTHYLTHIOCARBAMOYL) A82846B 1778.5 3 19.8 6 N LEU -(1-NAPHTHYLTHIOCARBAMOYL) -N DISACC -(p-CHLOROBENZYL) A82846B 1902.5 3 15.4 7 N LEU -(1-NAPHTHYLTHIOCARBAMOYL) -N DISACC -(p-PHENOXYBENZYL) A82846B 1960.6 3 17.1 8 N LEU -((p-CHLOROPHENYL) -THIOCARBAMOYL) A82846B 1763.0 4 20.5 9 N LEU -((p-METHOXYPHENYL)THIOCARBAMOYL) A82846B 1757.3 2 21.0 10 N LEU -((p-CHLOROPHENYL)-THIOCARBAMOYL)-N DISACC -(p-PHENOXYBENZYL)A82846B 1944.3 3 26.9 11 N LEU -((p-METHOXYPHENYL)THIOCARBAMOYL)-N DISACC -(p-PHENOXYBENZYL)A82846B 1940.3 3 26.0 12 N LEU -((p-CHLOROPHENYL)THIOCARBAMOYL) -N DISACC -(p-CHLOROBENZYL)A82846B 1887.5 4 24.8 13 N LEU -((p-METHOXYPHENYL)THIOCARBAMOYL) -N DISACC -(p-CHLOROBENZYL) A82846B 1882.5 3 25.2 14 N LEU -((p-NITROPHENYL)THIOCARBAMOYL)A82846B 1774.0 3 19.1 15 N LEU -((p-(DIMETHYLAMINO)-PHENYL) THIOCARBAMOYL) A82846B 1771.4 3 17.6 16 N LEU -((p-(BENZYLOXY)PHENYL)-THIOCARBAMOYL) A82846B 1834.4 3 23.3 17 N LEU -((p-n-BUTYLPHENYL) THIOCARBAMOYL) A82846B 1784.4 3 17.0 18 N LEU -((p-n-BUTYLPHENYL)THIOCARBAMOYL) -N DISACC -(p-PHENOXYBENZYL)A82846B 1966.5 3 21.4 19 N LEU -((p-(DIMETHYLAMINO)PHENYL) THIOCARBAMOYL) -N DISACC -(p-PHENOXYBENZYL) A82846B 1953.3 3 17.1 20 N LEU -((p-(BENZYLOXY)PHENYL)-THIOCARBAMOYL) -N DISACC -(p-PHENOXYBENZYL)A82846B 2016.3 3 21.1 21 N LEU -(PHENYLTHIOCARBAMOYL)-N DISACC -(p-n-BUTYLBENZYL)-A82846B 1874.6 3 19.0 22 N LEU -(PHENYLTHIOCARBAMOYL)-N DISACC -(p-(p-CHLOROPHENYL) -BENZYL)A828468 1928.5 3 20.3 23 N LEU -(PHENYLCARBAMOYL) A828468 1712.1 3 13.8 24 N LEU -(PHENYLCARBAMOYL)-N DISACC -(p-PHENOXYBENZYL) A82846B 1894.2 3 18.9 25 N LEU -(n-DECYLTHIOCARBAMOYL)-A82846B 1792.4 3 N.A. The compounds of the present invention are useful for the treatment of bacterial infections. Therefore, in another embodiment, the present invention is directed to the use of a compound of the invention in the preparation of a medicament for the treatment of bacterial infections. In this embodiment, the medicament can be used to control and treat infections due to various bacteria, but especially gram-positive bacteria. In a preferred embodiment, the medicament is used to control and treat infections due to bacteria resistant to existing antibacterials. For example, certain bacteria are resistant to methicillin, and yet others are resistant to vancomycin and/or teicoplanin. The present compounds provide a technique for controlling and treating infections due to such resistant bacterial species. In carrying out this embodiment of the invention, the medicament of the present invention can be administered by any of the conventional techniques, including the oral route and parenteral routes such as intravenous and intramuscular. The amount of compound to be employed is not critical and will vary depending on the particular compound employed, the route of administration, the severity of the infection, the interval between dosings, and other factors known to those skilled in the art. In general, a dose of from about 0.5 to about 100 mg/kg will be effective; and in many situations, lesser doses of from about 0.5 to about 50 mg/kg will be effective. A compound of the present invention can be administered in a single dose, but in the known manner of antibacterial therapy, a compound of the present invention is typically administered repeatedly over a period of time, such as a matter of days or weeks, to ensure control of the bacterial infection. Also in accordance with known antibacterial therapy, a compound of the present invention is typically formulated for convenient delivery of the requisite dose. Therefore, in another embodiment, the present invention is directed to a pharmaceutical formulation comprising a compound of the present invention, in combination with a pharmaceutically-acceptable carrier. Such carriers are well known for both oral and parenteral routes of delivery. In general, a formulation will comprise a compound of the present invention in a concentration of from about 0.1 to about 90% by weight, and often from about 1.0 to about 3%. The antibacterial efficacy of the present compounds is illustrated by Table II. The minimal inhibitory concentrations (MICs) were determined using a standard broth micro-dilution assay.

Claims: A compound of the formula wherein R 1 represents O or S; R 2 represents alkyl of C 1 -C 10 , phenyl, naphthyl, or phenyl substituted by one or two substituents, each of which is independently halo, loweralkyl of C 1 -C 4 , loweralkoxy of C 1 -C 4 , benzyloxy, nitro, or wherein each R 2a is independently loweralkyl of C 1 -C 4 ; and R 3 represents hydrogen or -CH 2 -R 3a wherein R 3a represents alkyl of C 1 -C 11 , alkyl of C 1 -C 11 -R 4 , or R 4 -(0 (0 or 1) -R 4 ) 0 or 1 , wherein each R 4 is independently phenyl or phenyl substituted by one or two substituents, each of which is independently halo, loweralkyl of C 1 -C 4 , loweralkoxy of C 1 -C 4 , or loweralkylthio of C 1 -C 4 , or a pharmaceutically acceptable salt thereof. A compound of Claim 1 in which R 1 is S. A compound of Claim 1 in which R 2 is phenyl. A compound of Claim 1 in which R 3 is -CH 2 -R 3a . A compound of Claim 1 in which R 3 is p-(p-chlorophenyl)benzyl. A pharmaceutical formulation comprising a compound of Claims 1 - 5 in combination with a pharmaceutically-acceptable diluent or carrier. A compound of Claims 1 - 5 for use as a pharmaceutical. The use of a compound of Claims 1 - 5 in the preparation of a medicament for the treatment of bacterial inefections. The use of Claim 8 wherein said bacterial infection is attributable to a vancomycin-resistant-enterococcus. A process for the preparation of a compound as claimed in Claims 1 - 5 which comprises reacting a parent glycopeptide of the formula wherein R 3 is as defined in Claim 1, with an isocyanate or isothiocyanate of the formula R 1 CN-R 2 wherein R 1 and R 2 are as defined in Claim 1, and if desired thereafter forming a pharmaceutically acceptable salt.

Inventors: THOMPSON RICHARD CRAIG, THOMPSON, RICHARD CRAIG
Applicants: LILLY CO ELI, ELI LILLY AND COMPANY
Application year: 1998
Main classification: C07K9
IPC codes: C07K9, A61P31, A61K38