PT99350A - PROCESS FOR THE PREPARATION OF OXINDOLE PEPTID ANTAGONISTS - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to novel oxindole derivatives, pharmaceutical compositions containing them and methods of administering them to a subject in need of inhibition of the binding of gastritis-releasing peptide receptors. It is known that gastrin releasing peptide (PLG) stimulates a wide variety of biological responses in different tissues and cell lines, including mitogenesis. PLG also plays an important role in the pathophysiology of small cell lung cancer. PLG inhibitors therefore have clinical utility as inhibitors of the pathophysiological response to PLG in diseases of humans. Prior art receptor binding PLG inhibitors are peptides, such as those disclosed in D.C. Heimbrook et al., &Quot; Peptides, Proceedings of the Eleventh American Peptide Symposium ", pages 56-59 (1989). The present invention provides oxindoles which are inhibitors of receptor binding PLG. Oxindoles have been described in U.S. Patents 4,464,380 and 4,644,005, both of which are hereby incorporated by reference, as inhibitors of aldose reductase. The present oxindoles and / or their inhibition activity of PLG receptor binding are not disclosed.

Summary of the Invention

According to the present invention, it has been found that certain novel oxindoles are active inhibitors of PLG receptor binding. These oxindols have the following general formula

wherein it is methyl, ethyl, or benzyl which is phenyl-substituted by one or two of chlorine or bromine; R is = CH-Ar or spirohydantoin; R3 is C1 -C4 alkyl, fluoro, chloro, bromo, iodo or R4; R 4 is hydrogen, or a 5- or 6-substituent as follows: -O (CH 2) n CONH 2, -O (CH 2) n OH, -O (CH 2) -CO 2 H, -OCH 2 CH (OH) CH 2 OH, or benzyloxy which is phenyl-substituted by ortho or metacarbocycl, hydroxymethyl or carbamoyl; or R4 represents two substituents: a 5-substituent as defined above and β-methyl; n is 0, 1, 2, 3 or 4; Ar is imidazolyl, thienyl, pyrrolyl, piperazinyl, naphthyl, or

r5

wherein R 5 is one of trifluoromethyl; or two of methyl, t-butyl or hydroxy; or one of methyl with one of hydroxy; or 3,5-di (t-butyl) -4-hydroxy; with the proviso that (1) R 3 and R 4 are not both hydrogen, (2) R 1 is methyl or ethyl when R 2 is = CH-Ar, and (3) R 3 is bromo or chloro and R 3 is 3,4-dichlorobenzyl when R2 is spirohydantoin.

The specific oxindols of formula I are those wherein R1 is methyl or ethyl, and those wherein R2 is = CH-Ar, wherein Ar is 3,5-di (t-butyl) -4-hydroxybenzyloxy.

Other specific compounds of formula I are those wherein R 3 is methyl, those wherein R 3 is methyl. and R 4 is 5-carbamoyl, 5-OCH 2 CONH 2, or 5-carboxybenzyloxy, and those wherein R 3 is methyl and R 4 is 5-carbamoyl-6-methyl, 5-OCH 2 CONH 2 or 5-carboxybenzoxy-6-methyl.

A preferred class of compounds of formula I is the class wherein R1 is 3,4-dichlorophenyl and R2 is spirohydantoin. The present invention further relates to a pharmaceutical composition having a receptor binding inhibitory activity to the PLG group and comprising a compound of formula I in an amount sufficient to cause inhibition of PLG receptor binding, and a carrier or pharmaceutical diluent. The present invention also relates to a method of inhibiting the binding of gastrin releasing peptides, which comprises administering to a subject in need of inhibition of gastrin releasing peptide receptor binding of a compound of formula formula I as defined above in an amount sufficient to cause said inhibition. The present invention also relates to a method of inhibiting gastrin releasing peptide receptor which comprises administering to a subject in need of inhibition of gastrin releasing peptide receptor binding of a compound of formula 6

R1

VIII

Wherein R 1 is methyl, ethyl or benzyl which is optionally

Phenyl is substituted by one or two of chlorine and bromine; and R is

The bromine or chlorine in an amount sufficient to cause said inhibition.

Detailed Description of the Invention

The oxindole compounds of the invention are made by different processes depending on R2 being = CH-Ar or spirohydantoin and the indole ring being 4-alkyl or 4-substituted hexy. The preparation of the oxindole compounds wherein R2 is spirohydantoin is described in U.S. Patent 4,464,380. According to this method, a compound of formula

is condensed with an alkali metal cyanide such as sodium cyanide or potassium cyanide to form the corresponding spirohydantoin oxindole wherein R is chloro or bromo and R 2 is as defined for formula I. This condensation is generally effected in the presence of a reaction-inert organic polar solvent, in which both the reactants and reaction products are miscible. Preferred organic molar solvents include cyclic ethers such as dioxane and tetrahydrofuran, lower alkylene glycols such as ethylene glycol and trimethenylene glycol, water miscible lower alkanols such as methanol, ethanol and isopropanol, and Î ±, β-dimethylacetamide. The reaction is usually conducted at a temperature between about 50 ° and about 150 ° C, for a time period of from about two hours to four days. While the amount of reagents used may vary, it is preferred to use a slight molar excess of the alkali metal cyanide reagent relative to the carbonyl ring starting material of formula II to obtain the maximum yield.

Compounds of formula I in which is = CHAr may be prepared in the manner described in Reaction Scheme I. R3, R4 and Ar in the formulas III and IV of the Scheme are as defined above with respect to formula I. Reaction of the oxindoles of formula III with the aldehydes of formula IV is generally conducted in a reaction-inert solvent. Suitable solvents include aromatic amines such as pyrrolidine or piperidine, aliphatic amines such as tetrahydrofuran and alcohols such as methanol, ethanol, propanol and t-butanol. According to a preferred method, the reaction solvent is methanol and pyrrolidine. The reaction is usually conducted at temperatures between about -10 ° C and about 80 ° C. A preferred reaction temperature is room temperature. The oxindole of formula III is advantageously first dissolved in a reaction-inert polar solvent, such as C1-C6 lower alkanol, for example methanol, before being dissolved with the aldehyde of formula IV. The reaction of compounds III with compounds IV is conducted in the presence of a base. Suitable bases are the alkali metal hydroxides such as sodium hydroxide, and the organic bases such as pyrrolidine and piperidine. A preferred base is pyrrolidine.

Alternatively, compounds of formula I in which is = CHAr may be prepared in the manner described in Scheme II. And Ar in the formulas IV, V and VI of the Scheme are as defined above with respect to the compounds of formula I. R 5 in formula VII is (CH 2) n CONH 2, (CH 2) n OH, (CH 2) n COO 2 H, CH 2 CH (OH) benzyl substituted by ortho or meta-carboxy, hydroxymethyl or carbamoyl. X in formula VII is halide such as chloride. The reaction of the N-R1-hydroxy-indoles of formula V with the aldehyde of formula IV proceeds in the manner described above with respect to Reaction Scheme I. Reaction of compounds VI with compounds VII proceeds in the presence of a catalyst. Suitable catalysts are lithium bis (trimethylsilyl) amide, lithium bis (dimethylphenylsilyl) amide, lithium t-butyl (lithium tri-alkylsilyl) amide and lithium hexamethyldisilylamide A preferred catalyst is bis trimethylsilyl) amide The reaction temperature generally ranges from about -78 ° C to about 10 ° C.

The preferred reaction temperature ranges from about -40Â ° C to -30Â ° C. The reaction generally proceeds in the presence of a reaction inert solvent. Suitable solvents are dimethylformamide, dimethylacetamide, and ethylene glycol dimethyl ether of tetrahydrofuran. Preferred solvents are dimethylformamide and dimethylacetamide.

Reaction Scheme I

I

V

"1

flrCHO - > I where R2 | = CHflr

III

IV

Reaction Scheme II

- > R 2 = CH 2

VII

The starting materials of formula V may be prepared by known methods. For example, N-methyl-N-chloroacetyl-p-anisidine can be reacted with aluminum trichloride to form N-methyl-5-hydroxyoxindole. The starting material of formula III can be prepared from the hydroxyindole derivatives of formula V by reaction with the compounds of formula VII as described above for the reaction of formula VI in Reaction Scheme II.

Compounds of formula VIII may be prepared in the manner described in U.S. Patent 4,464,380.

The novel compounds of formula I and the compounds of formula VIII are useful for the treatment of diseases in humans resulting from pathophysiological reactions to PLG, for example for the treatment of small cell lung cancer, for the treatment of disorders of the central nervous system such as psychosis, panic and madness diseases, for the treatment of gastrointestinal diseases such as gastric ulcers, and for the treatment of appetite disorders such as anorexia and bulimia.

The compounds of the invention may be administered alone but are generally administered in admixture with a pharmaceutical carrier selected having regard to the intended route of administration and standard pharmaceutical practice. For example, they may be administered orally or in the form of tablets containing excipients such as starch or lactose, or in the form of capsules, alone or in admixture with excipients, or in the form of elixirs or suspensions containing flavoring or coloring agents . They may be injected parenterally, for example intramuscularly, intravenously or subcutaneously. For parenteral administration, they are best used in the form of a sterile aqueous solution which may contain other solutes, for example, a sufficient amount of salt or glucose to render the solution isotonic. The present invention also provides pharmaceutical compositions comprising an effective amount of a compound of formula (I), together with a pharmaceutically acceptable diluent or carrier.

The compounds of the present invention may be administered to humans for the treatment of diseases either orally or parenterally and may be administered orally with 12

dosage levels of about 0.1 to 500 mg / kg / day, advantageously 0.5-50 mg / kg / day, taken in an individual dose or up to 3 divided doses. For intramuscular or intravenous administration, the dosage levels are about 0.1-200 mg / kg / day, advantageously 0.5-50 mg / kg / day. While intramuscular administration may be done in an individual dose or up to 3 divided doses, intravenous administration may comprise continuous immersion. The variations which will necessarily occur will depend upon the weight and condition of the subject being treated and the particular route of administration chosen, as is known to those skilled in the art. The activity of the present compounds in inhibiting the binding of PLG receptors can be demonstrated by the following in vivo assay, cells from a small cell lung carcinoma are implanted subcutaneously in athymic mice. These animals receive a test compound at determined time intervals to inhibit tumor growth. Untreated rats succumb to the invading cells. The in vitro activity of a test compound can be determined by an in vitro receptor binding assay. using the cell membranes derived from a small lung cell carcinoma. »

The following examples illustrate the present invention.

Example 1 A. N-Chloroacetyl-N-methylanisidine To a solution of 5.98 ml of chloroacetyl chloride in 68 ml of methylene dichloride under nitrogen at -10 ° C was added dropwise a mixture of N-methyl (9.3 g) and diisopropylethylamine (14.2 ml) in 20 ml of methylene dichloride. The resulting mixture was allowed to warm to room temperature and was stirred at this temperature for 7 hrs. Water (30 ml) was added and the organic layer was separated. Water (30 ml) was added again and the mixture was acidified to pH 2 with hydrochloric acid, stirred for 15 minutes and extracted with methylene dichloride. The organic layer was separated, washed, dried and evaporated to give the title compound, 11.5 g (79%), m / e 13 (specific mass). B. N-methyl-5-hydroxyindole

15.78 g (0.118 mol, 2.2 molar equivalents) of AlCl3 were added at room temperature under nitrogen to a 500 ml three-necked flask. The mixture was stirred with a mechanical stirrer and gradually heated to 220 ° C. At 47 ° C, a strong gaseous stream emerged. Fifteen minutes later, the mixture equilibrated at 221 ° C and stirring was continued at that temperature for two hours. After cooling to room temperature, ice water (200 ml) was added and the resulting mixture was stirred at room temperature overnight. The reaction mixture was filtered and the cake was washed with water. The wet cake was recrystallized from ethyl acetate and dried to provide 590 mg of the title product, m.p. 198-199 ° C (dec). Mass spectrum m / e 13. c. To a solution of 1-methyl-5-hydroxy-2-oxindole (2 g, 12 mmol) in dichloromethane ) in 60 ml of methanol were added 1.02 ml (12 mmol) of pyrrolidine followed by 2.86 g (12 mmol) of 3,5-di-tert-butyl-4-hydroxy-benzaldehyde and the resulting mixture was stirred at room temperature overnight. Then, the reaction mixture was poured into a mixture of 100 ml of ice water and 14

200 ml of 1N HCl. The solid formed was collected by filtration and dried to afford the title compound, 3.5 g (78%), mp 136-140 ° C (dec.). Mass spectrum m / e 379, NMR (DMSO) δ , 5 ppm and 9 ppm (2H of OH), 6.7-7.2 ppm (aromatic 5H), 3.4 ppm (3H of CH3 and 1.5 ppm (18H of tert -butyl) D. 1-Methyl- 3'-5'-tert-butyl-4'-hydroxyphenyl] -5- (2'-carbomethoxybenzyloxy) indole

The title compound of Step C (1.2 g, 3.16 mmol) was dissolved in 12.4 mL of dimethylformamide and cooled to -40øC under nitrogen. Then, the lithium bis (trimethylsilyl) amide (6.95 mL, 6.95 mmol) was added and the mixture was stirred at -40 ° C for 5 minutes. To the resulting mixture 1.08 g (3.79 mmol) of 2-bromo-ethyl benzoic acid methyl ester were added dropwise. The cooling bath was then removed and the reaction mixture was stirred at room temperature overnight. The reaction mixture was poured into a mixture of 100 ml of water with 200 ml of 1N HCl and then extracted into ethyl acetate. The organic layer was separated, washed with water and saturated aqueous NaCl solution, dried over anhydrous magnesium sulfate, filtered and evaporated to give the crude product, 1.6 g. Purification by silica gel column chromatography afforded the fractions eluted with chloroform, 820 mg (49%), m.p. 159-162 ° C (dec.). Mass Spectrum m / e 527, NMR (CDCl3 6.8-8.2) ppm (aromatic 9H), 4.9 and 5.2 ppm (3H, OH and CH2), 3.9 ppm (3H of OCOCH3) , 3.3 ppm (3H of N-CH3) and 1.4 ppm (9H of tert-butyl). And The title compound of Step D (400 mg, 0.6 mmol) was dissolved in dichloromethane (50 ml) and the title compound 76 mmol) was hydrolyzed by dissolving in 3.8 ml of tetrahydrofuran by adding 3.8 ml of methanol and then by introducing 3.8 ml of 6N NaOH. The resulting mixture was stirred at room temperature and then poured into a mixture of 100 ml of water and 100 ml of 1N HCl. The precipitates formed were collected by filtration, washed with water and dried to provide the desired compound, 350 mg (90%), m.p. 124-125 ° C. Mass Spectrum m / e 513. Anal. Calc'd for C 32 H 35 NO 5 • C = 74.81, H = 6.87, N = 2.73; Found: C = 74.68, H = 6.28, N = 2.53.

Example 2 To a solution of 1-methyl-5-hydroxy-2-oxindole oxindole (2-methyl-3-methylene-3,4- , 12 mmol) in 60 ml of methanol were added 1.02 ml (12 mmol) of pyrrolidine, followed by 2.86 g (12 mmol) of 3,5-di-tert-butyl-4-hydroxy -benzaldehyde. The resulting mixture was stirred at room temperature overnight. Then the reaction mixture was poured into a mixture of 100 ml of ice water and 200 ml of 1 N HCl. The formed solid was collected by filtration and dried to afford the title compound: 3.5 g (78%), m.p. 136-140 ° C (dec.). Mass Spectrum m / e 379. NMR (DMSO): 8.5. and 9 ppm (2H of OH), 6.7-7.2 ppm (aromatic 5H), 3.4 ppm (3H of CH3) and 1.5 ppm (18H of tert-butyl). The title compound from Step A (1.2 g, 3.16 mmol) was dissolved in dichloromethane mmoles) was dissolved in 12.4 ml of dimethylformamide and cooled to -40 ° C under nitrogen. Then, lithium bis (trimethylsilyl) amide (6.95 mL, 6.95 mmol) was added and the mixture was stirred at -40 ° C for five minutes. 1.08 g (3.79 mmol) of 2-bromoethyl benzoic acid methyl ester were added dropwise to the resulting mixture. After the addition, the cooling bath was removed and the reaction mixture was stirred at room temperature overnight. The reaction mixture was poured into a mixture of 100 ml of water and 200 ml of 1N HCl and extracted into ethyl acetate. The organic layer was separated, washed with water and saturated aqueous NaCl solution and dried over anhydrous magnesium sulfate, filtered and evaporated to give the crude product, 1.6 g. Purification by silica gel column chromatography afforded the fractions eluted with chloroform, 820 mg (49%), m.p. 159-162 ° C (dec.).

Mass spectrum m / e 527. NMR (CDCl3): 6.8-8.2 ppm (9H aromatic), 4.9 and 5.2 ppm (3H, OH and CH2), 3.9 ppm (3H of CH3), 3.3 ppm (3H of N-CH3) and 1.4 ppm (9H of tert-butyl). The benzyloxy ester of step B (400 mg, 0.6 mmol) was dissolved in dichloromethane 0.76 mmole) was hydrolyzed by dissolving in 3.8 ml of tetrahydrofuran and adding 3.8 ml of methanol. Then, 3.8 ml of 6N NaOH were introduced. The resulting mixture was stirred at room temperature overnight and poured into a mixture of 100 ml of water and 100 ml of 1N HCl. The formed precipitate was collected by filtration, washed, and dried to afford compound 17

350 mg (90%), m.p. 124-125 ° C. Mass spectrum m / e 513. Anal. Calc'd for C 20 H 20 NO 4. C = 74.81, H = 6.87, N = 2.73; Found C = 74.68, H = 6.28, N = 2.53.

Example 3

According to the procedure of Example 2, the following compounds of formula I were prepared.

18 »oμ Ό (ti 3σ * 3 νη 2 - -μB 2y uT iS f u

(B), and (b) in the presence of a compound of the formula: ## STR1 ## in which R 1 is hydrogen, , and (2), (2) and (3), and (4) and (4). M is 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, (1) (2) (1) (2) (1) (2) (2) (2) (2) 2 Γ Γ c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c 2 (1) (1) (1) (1) (2) (1) (1) 1 8 u u u u u u u u u u u u u u Ό Ό Ό Ό Ό m m m m m m m m m m m m m m m m m m m m m m m MM MM MM MM MM MM MM a 0O r ·} MM 1 sS σι un * OU> 3 * O) IHI • μ Q 0 ~ 0 - Λ · Η Λ · Η ia ή b 5á Μ X U X 6 S 0 3 0 3 o 1 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • v > J5 vn

or Ti Ti Wu. M M * »M *** υ u - Η O X ίαφ! ιΑ Λ

IR (KBr):

• M M M M M M C M M U U U U U

19

0 3 G S H - P &gt; N 2 &lt; o '&gt; p &lt; / RTI &gt; NS 77.11 8.53 &lt; SS 3 P &lt; 2 &gt; 75.10 7.06 m Ό o C 8 S S o o o o S S S Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό Ό;;;; 3. 3. 3. 3.. (H ** n · «») is N ΓΜ Ov tart <N_ 1> KV = es ^ C ' 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 12 11 12 11 12 11 12 13 14 15 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; NS in -sT Ι-Γ Γ Γ Γ N N Μ Μ Μ Μ Μ Μ Μ Μ -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 -5 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; N NP PS or cs'? S t O cc

cj

i • H

-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -NH - ccc -ii ϋ tn ϋ HO

(1) (2) (2) (1) (2) (1) (1) (2) (2) where: I + J + 1! -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 H

i • H T5 --I Ή LO -H nS - m or d G -H 0) -P Ή S • Η Λ 4J I --H Ti I LD -ri 'J5 Γ0 I - - - = 51 Γ-l CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH u 1

Ti I in

I -H o c S i i • H S + J O Φ iH E U

1 H-NMR (DMSO-d 6)

• H '• iH T I | Ti I f LO -H 1 1 LO * H ta ta no CO 1 h 1 1 -1-1 Q IH CC -H CD Φ -m mm ή d -H 1 -rH Ή C-.Η 0) 4-> ; MH D -H • ΗΛ X M-> I O § £ V% u u u

Claims (7)

20 A process for the preparation of a compound of formula I, .. .1 Characterized in that it comprises reacting a compound of formula ... wherein Hal 3 is hydrogen, C 1 -C 4 alkyl, fluoro, chloro, bromo, iodo or R 4; R 4 is hydrogen, or a 5- or 6-substituent such as -O (CH 2) n CO 2 NH 2, -O (CH 2) n OH, -O (CH 2) n CO 2 H, -OCH 2 CH (OH) CH 2 OH, or benzyloxy which is phenyl substituted by ortho or meta-carboxy, hydroxymethyl or carbamoyl; or R4 are two substituents: a 5-substituent as defined above and 6-methyl- provided that R2 and R4 are not both hydrogen; and Hal is one or two of chlorine or bromine with an alkali metal cyanide to give the compounds of formula I wherein R2 is spirohydantoin and R1 is benzyl which is phenyl-substituted by one or two chlorine or bromo; or the reaction of a compound of formula 21 ι * ψ · with an aldehyde of formula ArCHO wherein Ar is imidazolyl, thienyl, pyrrolyl, piperazyl, naphthyl or wherein R 5 is one of trifluoromethyl; or two of methyl, t-butyl or hydroxy; or one of methyl with one of hydroxy; to give the compounds of formula I wherein R2 is = CH-Ar and R1 is methyl or ethyl, and R3 and R4 are as defined above; or the reaction of a compound of formula wherein R1 is methyl, ethyl, or benzyl which is phenyl-substituted by one or two of chlorine or bromine; and Ar are as defined above, provided that (1) R 2 is methyl or ethyl when R 2 is = CH-Ar, and (2) R 3 is bromine or chlorine and R 1 is 3,4-dichlorobenzyl when R 2 is -hydantoin, with a halide CH2CH (OH) CH2OH, or benzyl substituted with ortho or meta-carbocyclic, hydroxymethyl or carbamoyl and X is halo. 23. The process of claim 1, wherein R1 is methyl or ethyl. 33. A process according to claim 1 or 2 wherein R2 is = CH-Ar wherein Ar is 3,5-di (t-butyl) -4-hydroxybenzyloxy. 43. A process as claimed in any one of claims 1 to 3, wherein R 1 is methyl. 53. A process as claimed in any one of claims 1 to 4, characterized in that R 5 is 5-carbamoyl, 5-O-CH 2 CNH 3, or 5-carboxybenzyloxy. A process according to claim 5, wherein R4 is 5-carbamoyl-6-methyl, 5-OCH2 CONH2-6-methyl, or 5-carboxybenzyloxy-6-methyl. 73. A process as claimed in claim 1, wherein R is 3,4-dichlorophenyl and R is spirohydantoin. Lisbon, October 28, 1991 J. PEREIRA DA CRUZ Official Agent for Industrial Property RUA VICTOR CORDON, 10-A 3.fl 1200 LISBOA