Carboxylic acid ester prodrug inhibitors of MEK

Abstract

The invention generally relates to compounds having structure I: ##STR00001## wherein x represents alkyl, aryl or het-aryl, each of y independently represents hydrogen or halogen and z represents hydrogen or alkyl. Further, said compounds are inhibitors of MEK 1, 2 and 5. Furthermore, the invention includes methods of making said compounds, compositions including said compounds and uses for inhibiting MEK 1, 2 and 5.

Claims

1. A method for preparing a compound of structure Ia or structure Ib: ##STR00012## the method comprising a reaction scheme selected from the group consisting of the following: ##STR00013## wherein: X.sup.1 is hydrogen, X.sup.2 is hydrogen, alkyl, aryl or hetaryl, Y.sup.1 is halogen, Z is hydrogen or alkyl, and Y.sup.4 is fluorine, Y.sup.5 is iodine, and Y.sup.2 and Y.sup.3 are hydrogen, or Y.sup.4 and Y.sup.5 are hydrogen, and Y.sup.2 and Y.sup.3 are halogen.

2. The method of claim 1, wherein Y.sup.4 and Y.sup.5 are hydrogen and Y.sup.2 and Y.sup.3 are fluorine.

3. The method of claim 1, wherein Y.sup.4 is fluorine, Y.sup.5 is iodine, and Y.sup.2 and Y.sup.3 are hydrogen.

4. A method for preparing an inhibitor of mitogen-activated protein kinase 1, 2 and 5, of structure Ia or structure Ib: ##STR00014## the method comprising a reaction scheme selected from the group consisting of the following: ##STR00015## wherein: X.sup.1 is hydrogen, X.sup.2 is hydrogen, alkyl, aryl or hetaryl, Y.sup.1 is halogen, Z is hydrogen or alkyl, and Y.sup.4 is fluorine, Y.sup.5 is iodine, and Y.sup.2 and Y.sup.3 are hydrogen, or Y.sup.4 and Y.sup.5 are hydrogen, and Y.sup.2 and Y.sup.3 are halogen.

5. The method of claim 4, wherein Y.sup.4 and Y.sup.5 are hydrogen and Y.sup.2 and Y.sup.3 are fluorine.

6. The method of claim 4, wherein Y.sup.4 is fluorine, Y.sup.5 is iodine, and Y.sup.2 and Y.sup.3 are hydrogen.

7. The method of claim 4, wherein Y.sup.1 and Y.sup.4 are fluorine, Y.sup.5 is iodine, and Y.sup.2 and Y.sup.3 are hydrogen.

Description

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(1) The invention relates to compounds having the following structure I:

(2) ##STR00004##

(3) wherein, X represents alkyl, aryl or hetaryl, each of Y independently represents hydrogen or halogen and Z represents hydrogen or alkyl.

(4) In certain embodiments, alkyl can include but is not limited to methyl, ethyl, propyl, and butyl. Further, in certain embodiments, halogen can include but is not limited to fluorine, chlorine, bromine and iodine.

(5) The compounds of the invention are inhibitors of mitogen-activated protein kinase (MAPK) 1, 2 and 5 (MEK 1, 2 and 5) Further, the invention includes methods of making said compounds, and their use in inhibiting MEK 1, 2 and 5 activity.

(6) Furthermore, the invention includes compositions that include a therapeutically effective amount of the compound having structure I to administer to a patient. As used herein, the term therapeutically effective amount means an amount or dosage such that, when administered in a physiologically tolerable composition, is sufficient to achieve an effective systemic concentration or local concentration in tissue to elicit a response in the tissue, system or individual to which it was administered. The term administering and the like means to administer a compound or composition systemically or locally, as directly into or onto a target tissue, to a patient whereby the compound or composition positively impacts the tissue to which it is targeted. The compound or composition may be administered by injection, topical administration and oral administration or by other methods alone or in combination with other known techniques. The term inhibit or the like includes the administration of a compound or composition to at least partially prevent symptoms, a disease, condition or disorder.

(7) Without intending to be bound by any theory, it is believed that a carboxylate can make an ionic interaction with an arginine in the proximity of the proposed allosteric binding site. A similar arginine residue exists in MEK1/2 although at a slightly different location. Further, it is believed that a carboxylic ester delivers a carboxylic acid across a cellular membrane as a prodrug to deliver a metabolically released active MEK inhibitor. The carboxylic acid released is similar to carboxylic acid NSAIDS.

(8) In certain embodiments, the compounds of the invention can be made in accordance with the following preparation schematic A:

(9) ##STR00005##

(10) In certain other embodiments, the compounds of the invention can be made in accordance with the following preparation schematic B:

(11) ##STR00006##

EXAMPLES

Chemical Synthesis/Biological Testing of Carboxylic Acid-Based Inhibitors of MEK 5

(12) TABLE-US-00001 TABLE I cellular cellular pERK1/2 pERK5 registration decrease decrease Structure ID (%) (%) U0126 99.72 0.28 SC-1-148 (SC-1-180 ) 98.5 20.1 SC-1-72 Ester 98.5 20.1 0 staurosporine 98.93 13 SC-1-175 64.4 2.1

(13) The above compounds identified in Table I were tested in a cellular assay and demonstrated the activity listed for cellular MEK1/2, MEK5 phsophorylation of their related ERK following induction by EFG and determined by western blot analysis. Compounds staurosporine and U0126 are included as standards.

(14) Experimental: Chemical Synthesis

(15) The chemical synthesis of the following compounds followed traditional nucleophilc displacements of a halogen by attack of an analide to give the desired compounds. In some instances, it was necessary to use an Ulmann coupling strategy.

(16) 3,4-Difluoro-2-((2-fluoro-4-iodophenyl)amino)benzoic Acid (SC-1-148 Acid)

(17) A 250 mL round bottom flask was charged with 2-fluoro-4-iodoaniline, (73; 2.38 g, 10.05 mmol), 2,3,4-trifluorobenzoic acid, (74; 1.8 g, 10.225 mmol), and 30 mL of anhydrous THF. The reaction mixture was cooled with an ice-bath to 0 C. and LiNH.sub.2 (561.2 mg, 24.45 mmol) was added in portions 3 portions over 10 min. The reaction was then warmed to 58 C. and stirred for 12 h. 1 N HCl was then added to the reaction mixture at 0 C. to obtain a final pH of 1.0 (red to pHydrion paper). The reaction mixture was extracted three times with 10 mL portions of Et.sub.2O, washed three times with 5 mL portions of 1 N HCl, washed with NaCl (aq, sat) and dried over Na.sub.2SO.sub.4. The extract was decanted and the solvent was removed under reduced pressure. The crude product was isolated on SiO.sub.2 using hexane/EA and provided 2.11 g (53%) of a white solid. mp: 199.0-200.1 C. (lit.sup.: 200-201 C.). SiO.sub.2 TLC R.sub.f 0.51 (2:1 hexane/EA). .sup.1H NMR (MeOD-d.sub.4): 7.86 (m, 1 H), 7.46 (d, J=1.6 Hz, 1 H), 7.38 (d, J=1.6 Hz, 1 H), 7.18 (m, 1 H, OH), 6.86 (m, 1 H), 6.72 (m, 1 H), 2.31 (m, 1 H, NH). Anal Calcd for C.sub.13H.sub.7F.sub.3INO.sub.2: C, 39.72; H, 1.79; N, 3.56. Found: C, 39.41; H, 1.91; N, 3.52.

(18) SC-1-14 Acid (Ullmann Coupling)

(19) A microwave reactor tube was charged with ortho-iodo benzoic acid (496 mg, 2 mmol), 2-fluoro-4-iodo aniline (237 mg, 1 mmol), K.sub.2CO.sub.3 (416 mg, 3 mmol), CuI (200 mg, 1.04 mmol) and 5 mL DMF/H.sub.2O (9:1). The reaction was subjected to 300 Watt microwave irradiation with the internal temperature maintained at 100 C. for 2 h. After completion of the reaction was observed by TLC, 1 N HCl (4 mL) was added to the reaction mixture to obtain a final pH of 6.0. The solvent was then removed under reduced pressure. The crude compound was isolated on SiO.sub.2 using hexane/EA to give 217 mg (61%) of white solid; mp: 176.6-177.0 C.

(20) SC-1-24 Amide

(21) A dry 100 mL round bottom flask was charged with SC-1-14, (140 mg, 0.39 mmol) and 5 mL of DCM. The reaction mixture was cooled on ice-bath to 0 C. 100 L of anhydrous DMF was added followed by dropwise addition of oxalyl chloride (70 L, 0.8 mmol) over 2 min at 0 C. The reaction was stirred at 23 C. for 2 h. The solvent was then removed under reduced pressure. The crude product was dissolved in 5 mL of DCM and the appropriate amine (0.5 mL, 11.5 mmol) was added neat at 23 C. The reaction was stirred at 23 C. for 2 h; completion of reaction was determined by TLC. A mixture of 10 mL of DCM and 5 mL of 5% Na.sub.2CO.sub.3 was added and the resultant mixture was extracted with DCM, washed with NaCl (aq, sat), and dried over Na.sub.2SO.sub.4. The extract was decanted and then the solvent was removed under reduced pressure and water chased with toluene. The crude product was isolated on SiO.sub.2 using EA/0.5% TEA/10% ethanol and recrystallised from HCl salt (ethereal HCl) to give 20 mg (12%) of off-white powder. mp: 217.2-217.5 C.

(22) SC-1-39 Acid

(23) A microwave reactor tube was charged with ortho-iodo benzoic acid (496 mg, 2 mmol), aniline (0.45 mL, 4 mmol), K.sub.2CO.sub.3 (832 mg, 6 mmol), CuI (400 mg, 2.08 mmol) and 10 mL DMF/H.sub.2O (9:1). The reaction was subjected to 300 Watt microwave irradiation with the internal temperature maintained at 100 C. for 1 h. After completion of the reaction was observed by TLC, 1 N HCl (9 mL) was added to the reaction mixture to obtain a final pH of 6.0. The solvent was then removed under reduced pressure and water chased with toluene. The crude compound was isolated on SiO.sub.2 using hexane/EA and recrystallised from toluene to give 267 mg (63%) of white solid; mp: 176.6-177.0 C.

(24) SC-1-175 Acid

(25) A 250 mL round bottom flask was charged with aniline (0.57 mL, 5.7 mmol), 2,3,4-trifluorobenzoic acid, (1 g, 5.7 mmol), and 15 mL of anhydrous THF. The reaction mixture was cooled with an ice-bath to 0 C. and LiNH.sub.2 (327 mg, 14.25 mmol) was added in portions 2 portions over 10 min. The reaction was then warmed to 58 C. (external temperature) and stirred for 7 h. 1 N HCl was then added to the reaction mixture at 0 C. to obtain a final pH of 1.0 (red to pHydrion paper). The reaction mixture was extracted three times with 5 mL portions of Et.sub.2O, washed three times with 5 mL portions of 1 N HCl, washed with NaCl (aq, sat) and dried over Na.sub.2SO.sub.4. The extract was decanted and the solvent was removed under reduced pressure. The crude product was isolated on SiO.sub.2 using hexane/EA and provided 606 mg (44%) yellow crystals. mp: 162.1-162.6 C. SiO.sub.2 TLC R.sub.f 0.61 (2:1 hexane/EA).

(26) Experimental: Biological Testing

(27) Western Blot Analysis of Potential MEK-5 Inhibitors

(28) The MDA-MB-231 triple negative breast cancer cell line was pretreated with compounds (10 M) for 30 min followed by stimulation with epidermal growth factor (EGF, 50 ng/mL) for 15 min. Vehicle-treated cells were pretreated with DMSO for 30 min prior to EGF stimulation for 15 min. Protein visualization and quantification analysis was performed using LI-COR Odyssey Imager.
*P<0.05 vs. Vehicle, one-way ANOVA followed by Tukey-Kramer test (n=3)

(29) While the invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will be readily apparent to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative system and method, and illustrate examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the invention.