WO1998043953A1 - Naphthalenesulphonic or carboxylic acids and their use as atypical beta-adrenoceptor agonists - Google Patents

Abstract

The invention relates to a compound of formula (I) wherein the groups N(R?3) and R4¿ are separated by at least 4 ring carbon atoms; R1 represents a phenyl, naphthyl, phenoxymethyl, thiazolyl, pyridyl or pyrimidyl group, optionally substituted by one or more substituents selected from halogen, hydroxy, C¿1-6?alkoxy, C1-6alkyl, nitro, cyano, hydroxymethyl, trifluoromethyl, NR?6R7¿, and NHSO¿2R?6; R2 represents hydrogen or C¿1-6?alkyl; R?3¿ represents hydrogen or C¿1-4?alkyl; R?4¿ represents CO¿2R?6 or SO¿3H; R?5 represents one or more groups independently selected from hydrogen, C¿1-6?alkyl, halogen, trifluoromethyl and C1-6alkoxy; n represents an integer from 1-6; R?6 and R7¿ independently represent hydrogen or C¿1-4?alkyl; or pharmaceutically acceptable derivatives thereof, to processes for their preparation and their use in the treatment of conditions susceptible of amelioration by an atypical beta-adrenoceptor agonist.

Description

NAPHTHALENESULPHONIC OR CARBOXYLIC ACIDS AND THEIR USE AS ATYPICAL BETA-ADRENOCEPTOR AGONISTS

This invention relates to a new class of chemical compounds and to their use in medicine. In particular, the invention concerns novel naphthalene derivatives, methods for their preparation, pharmaceutical compositions containing them and their use as selective agonists at atypical beta-adrenoceptors (also known as beta-3- adrenoceptors). Such receptors have been described for example by J R S Arch et. al., Nature, 309, 163-165 (1984); C Wilson et. al., Eur. J. Pharmacol., 100, 309- 319 (1984); L J Emorine et. al., Science, 245, 1118-1121 (1989); and A. Bianchetti et. al. Br. J. Pharmacol., 100, 831-839 (1990). Phenethanolamine derivatives having activity at atypical beta-adrenoceptors are disclosed in, for example, European Patent Applications EP-A-0455006 and EP-A-0543662.

Atypical beta-adrenoceptors belong to the family of adrenoceptors which mediate the physiological actions of the hormones adrenaline and noradrenaline. Subtypes of the adrenoceptors, c^ -, α₂-, ^β ₁-, ^β ₂- and β₃-(atypical) can be identified on the basis of their pharmacological properties and physiological effects. Chemical agents which stimulate or block these receptors (but not β₃) are widely used in clinical medicine. More recently, emphasis has been placed upon specific receptor selectivity in order to reduce side effects caused, in part, by interactions with other receptors. Atypical beta-adrenoceptors are known to occur in adipose tissue and the gastrointestinal tract.

Atypical beta-ad renoceptor agonists have been found to be particularly useful as thermogenic anti-obesity agents and as anti-diabetic agents. Compounds having atypical beta-adrenoceptor agonist activity have also been described as being useful in the treatment of hyperglycaemia, as animal growth promoters, as blood platelet aggregation inhibitors, as positive inotropic agents and as antiatherosclerotic agents, and as being useful in the treatment of glaucoma.

The invention therefore provides, in a first aspect, compounds of formula (I):

(I)

wherein

The groups N(R^) and R^ are separated by at least 4 ring carbon atoms; R¹ represents a phenyl, naphthyl, phenoxymethyl, thiazolyl, pyridyl or pyrmidyl group, optionally substituted by one or more substituents selected from halogen, hydroxy, C-j^alkoxy, Cη^alkyl, nitro, cyano, hydroxy methyl, trifluoromethyl, NR°R7,

R2 represents hydrogen or C^alkyl;

R represents hydrogen or C1.4 alkyl;

R⁴ represents CO2R⁶ or SO3H;

R5 represents one or more groups independently selected from hydrogen, C-|. ρalkyl, halogen, trifluoromethyl and Cι_ρalkoxy; n represents an integer from 1-6;

R6 and R? independently represent hydrogen or C-|_4 alkyl; or pharmaceutically acceptable derivatives thereof.

A preferred subclass of compounds of formula (I) is represented by formula (la)

wherein

The groups N(R^) and R⁴ are separated by at least 4 ring carbon atoms;

R¹ represents a phenyl, naphthyl, pyridyl or pyrmidyl group, optionally substituted by one or more substituents selected from halogen, hydroxy, C-μβalkoxy, C-j_6alkyl, nitro, cyano, hydroxymethyl, trifluoromethyl, NR⁶R⁷, and NHSO2R⁶;

R2 represents hydrogen or Cι_ρ alkyl;

R3 represents hydrogen or C-j_4 alkyl;

R⁴ represents CO2R⁶ or SO3H;

R5 represents one or more groups independently selected from hydrogen, C_η. 6^a'kyl, halogen, trifluoromethyl and Cη.ρalkoxy; n represents an integer from 1-6; R6 and R⁷ independently represent hydrogen or C-j_4 alkyl; or pharmaceutically acceptable derivatives thereof.

Referring to the general formula (I), the term 'alkyl' as used herein respectively contains the appropriate indicated number of carbon atoms and appropriately includes straight chained alkyl groups, typically methyl and ethyl groups, and straight chain and branched propyl and butyl groups. Similarly, the term 'alkoxy^* includes both straight and branched chain groups.

Referring to the general formula (I), halogen includes fluorine, chlorine, bromine and iodine. Suitably R¹ represents phenyl optionally substituted by one, two or three substituents selected from halogen, hydroxy, C^alkoxy, C^alkyl, nitro, cyano, hydroxymethyl and trifluoromethyl. Preferably R¹ represents phenyl substituted by a chlorine, fluorine or bromine atom or a methyl or trifluoromethyl group, which atom or group is preferably located in the meta position. More preferably R¹ represents phenyl substituted by a chlorine atom located in the meta position.

R² is suitably hydrogen or methyl.

R³ is suitably hydrogen or methyl. R³ is preferably hydrogen.

R⁴ is suitably CO2H, or SO3H. Preferably, R⁴ is CO2H.

R⁵ is suitably hydrogen.

A further preferred subgroup of the present invention is represented by a compound of formula (lb):

where the naphthyl amino group and R⁴ are separated by at least 4 ring carbon atoms

R2 represents hydrogen or C^alkyl;

R⁴ represents CO2H or SO3H; or pharmaceutically acceptable derivatives thereof.

It will be appreciated that references to a compound of formula (I) hereinafter are equally applicable to a compound of formula (la) or (lb).

It will be appreciated that the above compounds of formula (I) may contain optically active centres. The individual, isolated isomers and mixtures thereof, including racemates, are all within the scope of the present invention. Typically, mixtures of diastereomers of compounds of formula (I) may be obtained, which are enriched with greater than or equal to 80% by weight of one diastereomer. Particularly preferred compounds of formula (I) are those wherein the asymmetric carbon atoms in the - CH(OH)- group and the -CH(R²)- group are both in the (R)-configuration.

Suitable compounds of formula (I) of the invention include:

6-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-2- sulfonic acid;

5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-2- sulfonic acid;

6-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-1- sulfonic acid;

7-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- sulfonic acid; 5-{2-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-ethylamino}-naphthalene-2- sulfonic acid;

5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- carboxylic acid;

6-{2R-[2-(3-Chlorophenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- carboxylic acid;

6-{2R-[2-(3-Chlorophenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-1- carboxylic acid;

5-{2S-[2-(3-Chlorophenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- carboxylic acid; Methyl 5-{2S-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate;

Methyl 5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate; and pharmaceutically acceptable derivatives thereof.

Preferred compounds of the invention include: 5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- carboxylic acid; and pharmaceutically acceptable derivatives thereof.

By "a pharmaceutically acceptable derivative" is meant any pharmaceutically acceptable salt, ester, or salt of such ester, of a compound of formula (I) or any other compound which, upon administration to the recipient, is capable of providing (directly or indirectly) a compound of formula (I) or an active metabolite or residue thereof.

It will be appreciated by those skilled in the art that the compounds of formula (I) may be modified to provide pharmaceutically acceptable derivatives thereof at any of the functional groups in the compounds of formula (I). Of particular interest as such derivatives are compounds modified at the carboxyl function, hydroxyl functions or at amino groups.

It will be appreciated by those skilled in the art that the pharmaceutically acceptable derivatives of the compounds of formula (I) may be derivatised at more than one position.

Preferred pharmaceutically acceptable derivatives of the compounds of formula (I) are pharmaceutically acceptable salts thereof.

Pharmaceutically acceptable salts of the compounds of formula (I) include those derived from pharmaceutically acceptable inorganic and organic acids and bases. Examples of suitable acids include hydrochloric, hydrobromic, sulphuric, nitric, perchloric, fumaric, maleic, phosphoric, glycollic, lactic, salicylic, succinic, toluene- p- sulphonic, tartaric, acetic, citric, methanesulphonic, formic, benzoic, malonic, naphthalene-2-sulphonic and benzenesulphonic acids. Other acids such as oxalic, while not in themselves pharmaceutically acceptable may be useful in the preparation of salts useful as intermediates in obtaining compounds of the invention and their pharmaceutically acceptable acid addition salts.

Salts derived from appropriate bases include alkali metal (e.g. sodium), alkaline earth metal (e.g. magnesium), ammonium and NR₄ ⁺ (where R is C^alkyl) salts.

The compounds of formula (I) act as agonists at atypical beta -adrenoceptors and as such are useful in the treatment of clinical conditions susceptible to amelioration by administration of an atypical beta-ad renoceptor agonist. Such conditions include hyperglycaemia, obesity, hyperlipemia, irritable bowel syndrome and its associated pain, motility dysfunction, excessive gastrointestinal secretion, non-specific diarrhoea, neurogenic inflammation, regulation of intraocular pressure, triglyceridemia, diabetes, e.g. non-insulin-dependent diabetes mellitus (NIDDM or

Type II), such as obese NIDDM and non-obese NIDDM, diabetic complications such as retinopathy, nephropathy, neuropathy, cataracts, coronary heart diseases and arteriosclerosis, osteoporosis; and gastrointestinal disorders, particularly inflammatory gastrointestinal disorders. They are also of use in increasing the high- density-lipoprotein (HDL) cholesterol concentration and decreasing the triglyceride concentration in blood serum, especially human blood serum, and are therefore of potential use in the treatment and/or prophylaxis of atherosclerosis. They also may be useful for the treatment of hyperinsulinaemia, depression, muscle wasting, and urinary incontinence. Accordingly, the present invention provides, as a further aspect, a method of treatment of a mammal, including man, suffering from condition susceptible of amelioration by an atypical beta-ad renoceptor agonist which method comprises administering to the subject an effective amount of a compound of general formula (I) or a pharmaceutically acceptable derivative thereof. References in this specification to treatment include prophylactic treatment as well as the alleviation of symptoms.

In a further aspect, the invention provides the use of a compound of general formula (I) or a pharmaceutically acceptable salt or solvate thereof, for the manufacture of a medicament for the treatment of a condition susceptible of amelioration by an atypical beta-adrenoceptor agonist.

While it is possible that, for use in therapy, a compound of the invention may be administered as the raw chemical it is preferable to present the active ingredient as a pharmaceutical formulation.

The invention thus further provides a pharmaceutical formulation comprising a compound of formula (I) or a pharmaceutically acceptable derivative thereof together with one or more pharmaceutically acceptable carriers therefor and, optionally, other therapeutic and/or prophylactic ingredients. The carrier(s) or excipient(s) must be "acceptable" in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof. Thus, the compounds for use according to the present invention may be formulated for oral, buccal, parenteral, rectal or transdermal administration or in a form suitable for administration by inhalation or insufflation (either through the mouth or the nose).

For oral administration, the pharmaceutical compositions may take the form of, for example, tablets or capsules prepared by conventional means with pharmaceutically acceptable excipients such as binding agents (e.g. pregelatinised maize starch, polyvinylpyrrolidone or hydroxypropyl methylcellulose); fillers (e.g. lactose, microcrystalline cellulose or calcium hydrogen phosphate); lubricants (e.g. magnesium stearate, talc or silica); disintegrants (e.g. potato starch or sodium starch glycollate); or wetting agents (e.g. sodium lauryl sulphate). The tablets may be coated by methods well known in the art. Liquid preparations for oral administration may take the form of, for example, solutions, syrups or suspensions, or they may be presented as a dry product for constitution with water or other suitable vehicle before use. Such liquid preparations may be prepared by conventional means with pharmaceutically acceptable additives such as suspending agents (e.g. sorbitol syrup, cellulose derivatives or hydrogenated edible fats); emulsifying agents (e.g. ?

lecithin or acacia); non-aqueous vehicles (e.g. almond oil, oily esters, ethyl alcohol or fractionated vegetable oils); and preservatives (e.g. methyl or propyl-p- hydroxybenzoates or sorbic acid). The preparations may also contain buffer salts, flavouring, colouring and sweetening agents as appropriate. Preparations for oral administration may be suitably formulated to give controlled release of the active compound.

For buccal administration the compositions may take the form of tablets or lozenges formulated in conventional manner.

The compounds according to the present invention may be formulated for parenteral administration by injection e.g. by bolus injection or continuous infusion. Formulations for injection may be presented in unit dosage form e.g. in ampoules or in multi-dose containers, with an added preservative. The compositions may take such forms as suspensions, solutions or emulsions in oily or aqueous vehicles, and may contain formulatory agents such as suspending, stabilising and/or dispersing agents. Alternatively, the active ingredient may be in powder form for constitution with a suitable vehicle, e.g. sterile pyrogen-free water, before use.

The compounds according to the present invention may also be formulated in rectal compositions such as suppositories or retention enemas, e.g. containing conventional suppository bases such as cocoa butter or other glycerides. In addition to the formulations described previously, the compounds may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example subcutaneously, transcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the compounds according to the present invention may be formulated with suitable polymeric or hydrophobic materials (for example as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.

Suitable therapeutic ingredients which may be formulated with compounds of the invention, together with one or more pharmaceutical carriers or excipients, include ingredients which may be used in the same clinical conditions as those listed herein for atypical beta-adrenoceptor agonists. Such ingredients may include, for example, PPAR-gamma agonists.

A proposed dose of the compounds according to the present invention for administration to a human (of approximately 70kg body weight) is 0.1 mg to 1g, preferably to 1mg to 100mg of the active ingredient per unit dose, expressed as the weight of free base. The unit dose may be administered, for example, 1 to 4 times per day. The dose will depend on the route of administration. It will be appreciated that it may be necessary to make routine variations to the dosage depending on the age and weight of the patient as well as the severity of the condition to be treated. The precise dose and route of administration will ultimately be at the discretion of the attendant physician or veterinarian.

The compounds of the invention may be prepared by any of the processes known in the art for the preparation of similar compounds. For example, according to a first process (A) wherein R¹, R², R³, R⁵ and n are as defined as for formula (I), compounds of formula (I) may be prepared from of a compound of formula (II):

where p1 and P² are suitable protecting groups for oxygen and nitrogen groups respectively, R⁴ is CO2R⁶ or SO3H and R⁶ is C-|_6 alkyl, by deprotection of P¹ and P² under suitable conditions such as treatment with an acid, e.g. aqueous hydrochloric acid in a suitable solvent such as dioxane.

As a further process (B), compounds of formula (I) may be prepared from other compounds of formula (I). For instance, a compound of formula (I) where R6 is H may be prepared from a compound of formula (I) where Rβ is C-j_6 alkyl by hydrolysis, e.g. base hydrolysis with a reagent such as lithium hydroxide in a solvent such as tetrahydrofuran.

Compounds of formula (II) may be prepared by reaction of a compound of formula (III) with a compound of formula (IV):

where p1 and P² are suitable protecting groups for oxygen and nitrogen groups respectively, R⁴ is CO2R⁶ or SO3H and R⁶ is C-|_6 alkyl, in the presence of a reducing agent.

As a yet further process (C), the preparation of compounds of formula (II), as defined above, followed by step (A) may be combined without purification of intermediate products.

Compounds of formula (III) are described in WO95/33724 and as described herein.

Compounds of formula (IV) are known or may be prepared by standard methods. For example, where a compound of formula (IV) is a 5-amino-2-naphthoate ester, this may be prepared from a compound of formula (V)

where R$ and n are defined above and R6 is a C-j^alkyl group, by reaction with benzylamine and cesium carbonate in the presence of a suitable catalyst/catalysts, e.g. (R)-(+)-2,2^,-bis(diphenylphosphino)-1,1'-binaphthyl and tris(dibenzylideneacetone) dipalladium(O), followed by suitable reduction, e.g. hydrogenation, of the benzyl group.

Compounds of formula (V) are known or may be prepared by standard methods, e.g. Aust. J. Chem., 1965, 18, 1351-64.

Alternatively, a compound of formula (IV) which is a 5-amino-2-naphthoate ester may be obtained from a compound of formula (VI)

where R⁵ and n are defined above and P³ represents a suitable primary nitrogen protecting group, e.g. an isoindole, by reaction with carbon monoxide, under pressure and at elevated temperature, e.g. 100°C, in the presence of a suitable catalyst or catalysts such as palladium (II) acetate and 1,1'-bis(diphenylphosphino)- ferrocene and lithium chloride, in a suitable solvent such as triethylamine and methanoi, followed by deprotection of the amino protecting group under suitable conditions, e.g. hydrazine in methanoi at elevated temperature.

A compound of formula (VI) may be prepared from the corresponding 5-amino-2- naphthol by sequential reaction with a suitable reagent such as phthallic anhydride in a suitable solvent such as N,N-dimethylacetamide followed by reaction with trifluoromethanesulfonic anhydride and triethylamine in a suitable solvent such as dichloromethane.

Suitable reducing agents of use in the reactions include hydrogen in the presence of a catalyst, such as a noble metal catalyst, for example palladium, platinum or platinum oxide, Raney-nickel or hydride reducing agents such as borohydrides, for example sodium borohydride sodium triacetoxyborohydride or sodium cyanoborohydride. Suitable reaction conditions will be readily apparent to those skilled in the art and are further illustrated by the accompanying examples.

The protecting groups used in the preparation of compounds of formula (I) may be used in conventional manner. See for example 'Protective Groups in Organic Chemistry' Ed. J. F. W. McOmie (Plenum Press 1973) or 'Protective Groups in Organic Synthesis' by Theodora W Greene and P M G Wuts (John Wiley and Sons 1991).

Conventional amino protecting groups may include for example aralkyl groups, such as benzyl, diphenylmethyl or triphenylmethyl groups; and acyl groups such as N- benzyloxycarbonyl or t-butoxycarbonyl.

Conventional oxygen protecting groups may include for example alky silyl groups, such as trimethylsilyl, or tert-butyldimethylsilyl; alkylethers such as tetrahydropyranyl, or tert-butyl; or esters such as acetate.

Removal of any protecting groups present may be achieved by conventional procedures.

Atypical beta-adrenoceptor agonists are compounds which demonstrate a pharmacological response mediated at atypical beta-adrenoceptors. This activity has been be measured as the ability to stimulate lipolysis by rat adipocytes at sub- micromolar concentrations, in a response that is resistant to blockade by standard beta-adrenoceptor blocking drugs such as propranolol.

Another useful means of identifying an atypical beta-adrenoceptor agonist involves the measurement of agonist activity at atypical beta-adrenoceptors in the rat isolated lower oesophagus. Typically in this assay, a compound of general formula (I) for use according to the present invention has an equipotent molar ratio (EPMR) relevant to isoprenaline of less than 30. The rat oesophagus assay is based upon that described by Ford et. al., Br. J. Pharmacol., 105(suppl.), 235p, 1992.

A particularly useful method for determining agoinst activity at human atypical beta- adrenoceptors involves the use of Chinese hamster ovarian (CHO) cells transfected with the human beta-3-adrenoceptor according to Method 1. The cell lines may also be transfected with human beta-1- and beta-2- adrenoceptor in a similar manner to provide a method of determining the selectivity of the compounds of the invention at the three receptors.

Method 1

General cell culture guidelines are observed (Fershney, R.A. (1987) Culture of animal cells: A manual of basic technique. Wiley-Liss, Inc., N.Y.). A standard cell culture incubator is used (37°C, 5% C0₂ in air, 95% relative humidity). H β₃CHO cells are grown in DMEM/F12 (with pyroxidine-HCI, 15 mM HEPES, L-glutamine), supplanted with 10% heat-inactivated FBS, 500 μg/ml G418, 2 mM L-gluatmine, 100 units penicillin G and 100 μg streptomycin sulfate. One confluent flask of cells is trypsinised and resuspended in the above medium at a concentration of 30-40,000 cells/100 ul and plated into 96-well flat bottom plates. The cells are then used for assay within 18-24 hours. Experimental method:

The medium is aspirated from each well, and replaced with 180 μl DMEM/F12 with 500 mM IBMX. Antagonists, if required, are added at this stage. The plate is then placed back in the incubator for 30min. Drugs are then added to the wells (20μl, 100x required final concentration) for 60 min. Responses were determined by measuring cAMP levels of a 20 ul sample of extracellular media using a scintillation proximity based radio-immunoassay (NEN Flashplates).

CHO-6CRE-luciferase cell lines which stably express hβ₃ receptors are seeded at 30,000 cells/well for 24 hr in DMEM/F12 containing 10% FBS. Media is removed from the cells and replaced with DMEM/F12 buffer (180 μl) containing 300 mM IBMX and 1 mM ascorbic acid for 30 min prior to addition of compound. Vehicle or agonist (20 μl) is added and incubated at 37°C for 60 minutes. At the end of the incubation period, samples of extracellular media are removed for direct assay in cAMP Flashplates (NEN).

The relative potency of each test agonist (EPMR) is compared to isoprenaline as follows:

EPMR = EC₃₀ agonist /EC₃₀ isoprenaline wherein EC₃₀ is the molar concentration of agonist which produces 30% of the maximum possible response for that agonist. Using the non-selective beta-adrenoceptor agonist isoprenaline as a reference agonist, compounds selective for atypical beta-adrenoceptors should preferably be a minimum of 10-30 times less potent than isoprenaline at β or β₂-adrenoceptors and, more preferably, 300-1000 times less potent than isoprenaline at β or β₂- adrenoceptors. In addition to their activity at the atypical beta adrenoceptor, the compounds of the present invention have been determined to be highly selective for this receptor compared to the β or β₂-adrenoceptors.

The invention is further illustrated by the following intermediates and examples. All temperatures are in degrees centigrade.

HPLC characterisation was carried out where specified using a Dynamax-60A C18 83-201 -C, 25cm x 4.6mm column, eluting with 5-40% CH₃CN in H₂0 with 0.1 % TFA buffer, with a programme time of 30.0 min and flow rate of 1.5ml_. min). Retention times are expressed as t_r in minutes. Optical rotation values are expressed as [ ]__ values.

Mass spectra (ms) were obtained using electrospray (positive or negative ion) analysis.

Intermediate 1

(R)-(3-chloro-phenyl)-hydroxy-acetic acid methyl ester

A solution of (R)-(3-chloro-phenyl)-hydroxy-acetic acid (19.98g) in methanoi (250ml) containing concentrated sulphuric acid (1ml) was heated under reflux for 6.5h. The solution was cooled, neutralised with aqueous sodium bicarbonate solution, and concentrated. The residue, dissolved in ethyl acetate, was washed with aqueous sodium bicarbonate solution, dried, and evaporated to give the title compound (21.13g) as a pale-yellow oil:

[α]_D = -104° (c 1.00 MeOH)

Intermediate 2

(R)-(3-chloro-phenyl)-(tert-butyl-dimethyl-silanoxy)-acetic acid methyl ester

A solution of (R)-(3-chloro-phenyl)-hydroxy-acetic acid methyl ester (21. Og), imidazole (14.25g), and tert-butyldimethylsilyl chloride (25. Og) in N,N- dimethylformamide (250ml) was stirred at room temperature for 18h. The mixture was poured into water and extracted with ethyl acetate. The combined extracts were washed with water and saturated brine, dried, and concentrated. The residue was purified by chromatography, eluting with cyclohexane:ethyl acetate (9:1) to give the title compound as a colourless oil (32.63g)

[α]_D = -55.4° (c 1.21 MeOH)

Intermediate 3

(R)-(3-chloro-phenyl)-(tert-butyl-dimethyl-silanoxy)-acetaldehyde

To a stirred solution of (R)-(3-chloro-phenyl)-(tert-butyl-dimethyl-silanoxy)-acetic acid methyl ester (4.0g) in anhydrous ether (10ml) maintained at <-65 °C was added dropwise a 1.5M solution of di-isobututylaluminium hydride in toluene (10ml). When addition was complete the solution was stirred at -65 °C for a further hour, then quenched with methanoi (10ml). The mixture was allowed to attain room temperature, was adsorbed onto silica and purified by chromatography eluting with cyclohexane:ethyl acetate (9:1) to give the title compound as a colourless liquid (3.09g)

[α]_D = -45.3° (c 1.50 MeOH)

Intermediate 4

5-Amino-2-naphthalene carboxylic acid methyl ester (i)

A solution of methyl-2-naphthoate (10.00g) in acetic acid (54mL) was stirred at 0°C as nitronium tetrafluoroborate (7.13g) was added. The solution was stirred at 0°C for one hour then for three hours at room temperature. The mixture was diluted with water then extracted with chloroform. The organic layer was washed with saturated aqueous NaHC0₃, dried with MgS0₄, filtered and evaporated. The residue was chromatographed on silica gel, eluting with ethyl acetate:hexane (1 :9) to yield a mixture of nitro - naphthalene-2-carboxylic acid methyl esters (8.63g). The mixture was suspended in methanoi (365mL) and stirred as 10% palladium on carbon (1.05g) was added. The resulting mixture was stirred under a hydrogen atmosphere for 18 hours then filtered through celite and evaporated. The residue was chromatographed on silica gel, eluting with ethyl acetate: hexane (1 :4), then recrystallized from methanoi to yield the title compound (1.005g)

Assay Found: C, 71.72; H, 5.58; N, 6.97. C₁₂H₁₁N0₂ requires: C, 71.63; H, 5.5 I ; N, 6.96.

Intermediate 5

2-(6-Hydroxy-1-naphthyl)-1H-isoindole-1 ,3(2H)-dione

A solution of 5-amino-2-naphthol (25.24 g) and phthalic anhydride (24.66 g) in N,N- dimethyl acetamide (200 mL) was stirred at 172 °C under nitrogen for 3.5 h. The reaction mixture was then concentrated at 50 °C and 0.3 Torr, and methanoi (600 mL) was added to the resulting dark red residue. The mixture was sonicated and heated, resulting in the formation of a crystalline solid. The mixture was then cooled to 0 °C and the crystalline solid was isolated by filtration, rinsing with methanoi (50 mL). It was then dried under vacuum to afford the title compound as a colorless crystalline solid (18.96 g). The filtrate was concentrated and again triturated with methanoi (200 mL) to afford a second crop after filtration and drying under vacuum (18.56 g).

Assay: Found: C 74.44, H 3.94, N 4.96% C18H11 NO3 requires C 74.73, H 3.83, N 4.84% Similarly prepared were:

Intermediate 6

2-(6-Bromo-2-naphthyl)-1 H-isoindole-1 ,3(2H)-dione as a colorless crystalline solid (10.81 g),

Assay: Found: C 61.30, H 3.09, N 3.93% Ci8HifjN02Br requires C 61.39, H 2.86, N 3.98% from 6-bromo-2-naphthalenamine (9.50 g) (Journal of Organic Chemistry, 25, 214 1960).

Intermediate 7

2-(5-Hydroxy-2-naphthyl)-1 H-isoindole-1 ,3(2H)-dione as a red solid (contaminated with N,N-dimethyl acetamide) (1.10 g),

Electrospray ms (positive ion) (M+H) 290 from 6-amino-1-naphthol (4.20 g).

Intermediate 8

5-(1 ,3-Dioxo-1 ,3-dihydro-2 -/-isoindol-2-yl)-2-naphthyl trifluoromethanesulfonate

Trifluoromethanesulfonic anhydride (10.09 mL) was added dropwise under nitrogen to a slurry of 2-(6-hydroxy-1-naphthyl)-1H-isoindole-1 ,3(2H)-dione (14.46 g) in dichloromethane (200 mL) containing triethylamine (13.9 mL) at -78 °C. After 2 h, 1

N hydrochloric acid (100 mL) was added. The mixture was allowed to warm to room temperature, and the two phases were separated. The yellow aqueous phase was extracted with dichloromethane, and the extracts were combined with the organic layer. The combined organic phase was then washed with 1 N hydrochloric acid (50 mL), followed by saturated aqueous sodium chloride solution (50 mL). The solution was dried (magnesium sulfate), decolorized over activated charcoal, and filtered through a silica plug, eluting with hexane/ethyl acetate (4:1). The filtrate was then concentrated to afford the title compound as a light pink crystalline solid (19.71 g). An analytical sample was obtained via recrystallization from hexane/ethyl acetate

(4:1).

Assay: Found: C 54.07, H 2.37, N 3.28, S 7.58% C19H10NO5SF requires C 54.16, H 2.39, N 3.32, S 7.61% Similarly prepared were:

Intermediate 9

6-(1 ,3-Dioxo-1 ,3-dihydro-2/-/-isoindol-2-yl)-1 -naphthyl trifluoromethanesulfonate as an off-white crystalline solid (481 mg),

¹H n.m.r. (CDCI3): δ values include 7.54 (s), 7.54-7.60 (m), 7.78 (dd), 7.81-7.87 (m), 7.94 (dd), 8.00-8.04 (m), 8.08 (d), 8.21 (d) from 2-(5-hydroxy-2-naphthyl)-1H-isoindole-1 ,3(2/-/)-dione (950 mg).

Intermediate 10

Methyl 5-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-2-naphthoate as a colorless crystalline solid (240 mg),

Assay: Found: C 72.34, H 3.95, N 4.17% C20H13NO4 requires C 72.50, H 3.95, N 4.23% from 5-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-2-naphthyl trifluoromethanesulfonate (313 mg).

Intermediate 11

Methyl 6-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-2-naphthoate A solution of 2-(6-bromo-2-naphthyl)-1H-isoindole-1 ,3(2/-/)-dione (3.52 g), palladium (II) acetate (111 mg), 1 ,1'-bis(diphenylphosphino)-ferrocene (554 mg), lithium chloride (1.271 g), triethylamine (6.97 mL), and methanoi (8.10 mL) in N,N- dimethylformamide (50 mL) was stirred in a Parr bomb at 100 °C under 30 psi of carbon monoxide for 3 h. Upon cooling to room temperature, the bomb was vented, and the contents were partitioned between ethyl acetate (800 mL) and 1 N hydrochloric acid (400 mL). The aqueous layer and undissolved solids were then extracted with ethyl acetate. These extracts were combined with the organic layer, washed with 1 N hydrochloric acid and saturated aqueous sodium chloride solution, and dried (magnesium sulfate). Filtration through celite and concentration under vacuum afforded a black solid, which was chromatographed on silica gel, eluting with hexane/ethyl acetate (4:1 to 1 :2). The product was then recrystallized from ethyl acetate to afford the title compound (1.82 g) as colorless crystals. Assay: Found: C 72.39, H 4.02, N 4.18% C20H13NO4 requires C 72.50, H 3.95, N 4.23%

Similarly prepared was: Intermediate 12

Methyl 6-(1 ,3-dioxo-1 ,3-dihydro-2 -/-isoindol-2-yl)-1 -naphthoate as an off-white crystalline solid (73 mg),

Electrospray ms (positive ion) (M+H) 332 from 6-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-1 -naphthyl trifluoromethanesulfonate (290 mg).

Intermediate 13

5-Benzylamino-naphthalene-2-carboxylic acid methyl ester

Cesium carbonate (15.48 g) was added to a solution of 5-bromo-naphthalene-2- carboxylic acid methyl ester (9.0 g) (Aust. J. Chem. 18, 1351-64, 1965) and benzylamine (4.46 mL)in toluene (100 mL), and the mixture was degassed. (R)-(+)- 2,2'-bis(diphenylphosphino)-1 ,1'-binaphthyl (315.2 mg) and tris(dibenzylideneacetone) dipalladium(O) (154.4 mg) were added and the reaction mixture was heated at 81 °C for 16 hours. 5-Benzylamino-naphthalene-2-carboxylic acid methyl ester was obtained by collecting the resulting yellow solid (4.86g) and rinsing with tetrahydrofuran. Additional product (2.40 g) was obtained by washing the filtrate with water, concentrating and triturating the residue with diethyl ether.

¹ H n.m.r. (DMSO-d₆): δ values include 3.88 (s), 4.47 (d), 6.45-6.49 (m), 7.11 (t), 7.16-7.24 (m), 7.28 (t), 7.37 (d), 7.86 (dd), 8.34 (d), 8.42 (s).

Intermediate 14

5-Amino-2-naphthalene carboxylic acid methyl ester (ii)

A slurry of methyl 5-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-2-naphthoate (3.24 g) in methanoi (100 mL) was heated to reflux. Hydrazine (313 μL) was then added, and the reaction mixture was stirred. The mixture was cooled after 3 h, and volatiles were removed under vacuum. The yellow solid that remained was slurried in water (100 mL) containing 1 M hydrochloric acid (12.25 mL), and heated at 55 °C for 15 min. The mixture was then cooled to room temperature and filtered to remove precipitated solids. The filter plug was extracted with ethyl acetate/methanol (10:1). These extracts were combined and washed with saturated aqueous sodium bicarbonate. Precipitated solids were drawn off with the aqueous layer. The pH of the filtrate was then adjusted to a value of ca. 8 with 1 M aqueous sodium hydroxide solution, and the resulting cloudy mixture was extracted with ethyl acetate. The extracts were combined with those from the filter plug, dried (magnesium sulfate), and concentrated to afford the title compound (1.62 g).

Similarly prepared were: Intermediate 15

Methyl 6-amino-2-naphthoate as a slightly pink solid (335 mg),

Assay: Found: C 71.63, H 5.51 , N 6.96% C12H11 NO2 requires C 71.44, H 5.58, N 6.90% from methyl 6-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-2-naphthoate (994 mg).

Intermediate 16

Methyl 6-amino-1-naphthoate as a colorless oil (83 mg),

Electrospray ms (positive ion) (M+H) 202 from methyl 6-(1 ,3-dioxo-1 ,3-dihydro-2H-isoindol-2-yl)-1-naphthoate (168 mg).

Intermediate 17

5-Amino-2-naphthalene carboxylic acid methyl ester (iii)

To a solution of 5-benzylamino-naphthalene-2-carboxylic acid methyl ester (8.2 g) in tetrahydrofuran (115 mL) was added 10% palladium on carbon (2.5 g). The reaction vessel was evacuated and flushed with nitrogen, followed by hydrogen. The mixture was then stirred under hydrogen (1 atm) for 4 hours. The reaction mixture was filtered through celite and concentrated to afford the title compound (5.47 g) as a yellow solid.

Intermediate 18 Methyl (2S)-2-[(2R)-2-[fetf-butyl(dimethyl)silyl]oxy-2-(3- chlorophenyl)ethyl]aminopropanoate

A solution of (2R)-2-[terf-butyl(dimethyl)silyl]oxy-2-(3-chlorophenyl)ethanal (5.0 g) in dichloromethane was stirred in the presence of 4 A molesieves (ca. 50 beads) for 5 min. L-alanine methyl ester (2.45 g) was added, and the mixture was stirred for an additional 5 min. Sodium triacetoxyborohydride (5.6 g) was added, and the cloudy mixture was stirred at room temperature for 2 h. The reaction mixture was then diluted with saturated aqueous sodium bicarbonate solution (200 mL), and extracted with dichloromethane (3X150 mL). The combined organic layers were washed with saturated aqueous sodium chloride (150 mL), dried (magnesium sulfate), and concentrated under vacuum to afford a yellow oil (5.0 g), which was chromatographed on silica gel. Elution with hexane/ethyl acetate (9:1) afforded the title compound as a pale yellow oil (4.0 g).

Electrospray ms (positive ion) (M+H) 372

Intermediate 19

Methyl (2S)-2-(tert-butoxycarbonyl)r(2R)-2-[tert-butyl(dimethyl)silylloxy-2-(3- chlorophenyl)ethyl]aminopropanoate

Di-tert-butyl dicarbonate (2.05 g) was added to methyl (2S)-2-[(2R)-2-[tert- butyl(dimethyl)silyl]oxy-2-(3-chlorophenyl)ethyl]aminopropanoate (3.50 g), and the mixture was heated at 95 °C under nitrogen for 10 min. The solution was cooled to room temperature and chromatographed on silica gel, eluting with hexane/ethyl acetate (95:5). The title compound (4.15 g) was obtained as a colorless oil.

Electrospray ms (positive ion) (M+Na) 494/496

Intermediate 20

{2S-(tert-butoxycarbonyl)-[2R-(tert-butyldimethylsilanoxy)-2-(3-chlorophenyl)-ethyl1- amino}propionaldehyde

Diisobutylaluminum hydride (4 mL, 1.5 M in toluene) was added dropwise under nitrogen to a solution of methyl (2S)-2-(fetf-butoxycarbonyl)[(2R)-2-[tetf- butyl(dimethyl)silyl]oxy-2-(3-chlorophenyl)ethyl]aminopropanoate (1.28 g) in toluene (20 mL) at -78 °C. The resulting colorless solution was stirred at this temperature for 90 min, before a saturated aqueous solution of Rochelle's salt (20 mL) was added dropwise. The resulting mixture was allowed to warm to room temperature, and was then filtered through celite, rinsing with water (50 mL) and ethyl acetate. The filtrate was separated into its two layers, and the aqueous layer was extracted with ethyl acetate. The extracts were combined with the organic layer of the filtrate, washed with saturated aqueous sodium chloride solution (20 mL), dried (magnesium sulfate), and concentrated to afford the title compound as a colorless oil (1.08 g).

¹H n.m.r. (CDCI3): δ values include 0.00, 0.03, and 0.07 (3s), 0.22 and 0.24 (2s), 1.06 (s), 1.46 and 1.51 (2d), 1.62 and 1.65 (2s), 5.11 and 5.27 (2m), 7.36-7.60 (m), 9.76 and 9.83 (2s)

Intermediate 21

Methyl 6-[((2R)-2-(tert-butoxycarbonyl)[(2R)-2-[tert-butyl(dimethyl)silyl]oxy-2-(3- chlorophenyl)ethyl]aminopropyl)amino]-2-naphthoate

Methyl 6-amino-2-naphthoate (201 mg) was dissolved in a 0.14 M solution of {2R- (tert-butoxycarbonyl)-[2R-(tert-butyldimethylsilanoxy)-2-(3-chlorophenyl)-ethyl]- aminojpropionaldehyde in 1 ,2-dichloroethane (12.0 mL) under nitrogen. Acetic acid (87μL ) and 4 A molsieves (4 beads) were added, and the mixture was stirred for 25 min. Sodium triacetoxyborohydride (636 mg) was then added, and the tan mixture was stirred at room temperature for 17 h, before being diluted with ethyl acetate (30 mL) and a saturated aqueous solution of Rochelle's salt (15 mL). The mixture was filtered through celite, rinsing with ethylacetate (30 mL), and the two layers were separated. The aqueous phase was extracted with ethyl acetate. The extracts were then combined with the organic phase, dried (magnesium sulfate), and concentrated to a yellow oil. Silica gel chromatography, eluting with hexane/ethyl acetate (10:1), afforded the crude title compound (804 mg) which was used in the next step without further purification.

Electrospray ms (positive ion) (M+H) 627/629

Similarly prepared were:

Intermediate 22

Methyl 6-[((2R)-2-(fett-butoxycarbonyl)[(2f?)-2-[.ett-butyl(dimethyl)silyl]oxy-2-(3- chlorophenyl)ethyl]aminopropyl)amino]-1 -naphthoate as a yellow oil (260 mg), low resolution MS (ES+) 627/629 from methyl 6-amino-1 -naphthoate (85 mg) and {2R-(tert-butoxycarbonyl)-[2R-(tert- butyldimethylsilanoxy)-2-(3-chlorophenyl)-ethyl]-amino}propionaldehyde in 1 ,2- dichloroethane (6.0 mL, 0.83 mmol of aldehyde). Intermediate 23

Methyl 5-[((2S)-2-(tetf-butoxycarbonyl)[(2R)-2-[.etf-butyl(dimethyl)silyl]oxy-2-(3- chlorophenyl)ethyl]aminopropyl)amino]-2-naphthoate as a pale yellow oil (720 mg), low resolution MS (ES+) 627/629 from methyl 5-amino-2-naphthoate (328 mg) and {2S-(tert-butoxycarbonyl)-[2R-(tert- butyldimethylsilanoxy)-2-(3-chlorophenyl)-ethyl]-amino}propionaldehyde (1.08 g).

Example 1

6-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-2- sulfonic acid

A suspension of 6-amino-2-napthalene sulfonic acid (0.505g) and {2R-(tert- butoxycarbonyl)-[2R-(tenf-butyl-dimethyl-silanoxy)-2-(3-chloro-phenyl)-ethyl]-amino}- propionaldehyde (0.500g) in Λ/,Λ/-dimethylformamide (8.1mL) was stirred for ten minutes before the addition of sodium triacetoxyborohydride (0.479g). The mixture was stirred for 18 hours. A 15% aqueous solution of Rochelle's salts was added and the mixture was stirred for one hour. The mixture was extracted with toluene. The organic layer was dried with magnesium sulfate, concentrated, and evaporated to a dark oil, which was purified by chromatography on silica gel with chloroform:methanol:water (60:30:4) to give the blocked compound as an oil (0.38g). The oil was dissolved in tetrahydrofuran (4mL) and 6N hydrochloric acid (4mL) was added. The mixture was stirred at room temperature for two days. The solution was neutralized with ammonium hydroxide and evaporated. The residue was purified by column chromatography on silica gel with chloroform:methanol:water:ammonium hydroxide (60:30:2:2) to give the title compound as an oil. The sample was solidified with ethanohwater to yield the title compound as a tan powder (87.1mg).

¹H NMR (DMSO -d6) : δ values include 1.29 (d), 3.09 (br m), 3.24(br m), 3.50(br m), 4.97(d), 6.23(br m), 6.30(), 6.82(s), 6.98(m), 7.37(m), 7.48(m), 8.62(br s).

HPLC: t_r= 16.2 min (t₀=1.6min).

Example 2

5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-2- sulfonic acid

A suspension of 5-amino-2-napthalene sulfonic acid (0.118g) and {2R-(tert- butoxycarbonyl)-[2R-(tert-butyl-dimethyl-silanoxy)-2-(3-chloro-phenyl)-ethyl]-amino}- propionaldehyde (0.115g) in N,N-dimethylformamide (1.9mL) was stirred for ten minutes before the addition of sodium triacetoxyborohydride (0.113g). The mixture was stirred for 18 hours. A 15% aqueous solution of Rochelle's salts was added and the mixture was stirred for one hour. The mixture was extracted with toluene. The organic layer was dried (magnesium sulfate) and concentrated to a dark oil. The residue was dissolved in dichloromethane (10mL) , trifluoroacetic acid (1 mL) was added, and the resulting solution was stirred at room temperature for 4 hours before beingconcentrated. The residue was redissolved in 1 ,4-dioxane (3.3mL), and6N hydrochloric acid (3.3mL) was added. The mixture was stirred at room temperature for 18 hours then concentrated to a purple solid, which was purified by column chromatography on silica gel with chloroform:methanol:water:ammonium hydroxide (60:30:2:2). The concentrated extracts were slurried with ethanol to yield the title compound as a light yellow powder (21.5mg).

¹H NMR (DMSO -d6) : δ values include 1.36 (d), 3.15(br m), 3.26(m, 1), 3.43(br m), 3.62(br m), 4.97(d), 6.35(br m), 6.66(d), 7.28-7.16(m), 7.40-7.30(m), 7.42(m), 7.54(s), 7.66(d), 8.02(s), 8.13(d), 8.61(br s).

HPLC: t_r= 19.4 min (to=1.6min).

Example 3

6-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-1- sulfonic acid

A suspension of 6-amino-1-napthalene sulfonic acid (0.118g) and {2R-(tert- butoxycarbonyl)-[2R-(tert-butyl-dimethyl-silanoxy)-2-(3-chloro-phenyl)-ethyl]-amino}- propionaldehyde (0.115g) in Λ/,Λ/-dimethylformamide (1.9mL) was stirred for ten minutes before the addition of sodium triacetoxyborohydride (0.113g). The mixture was stirred for 18 hours. A 15% aqueous solution of Rochelle's salts was added and the mixture was stirred for 30 minutes. The mixture was extracted with toluene, and the organic layer was dried (magnesium sulfate) and concentrated to a dark oil, which was purified by chromatography on silica gel with chloroform:methanol:water (60:30:4) to give the blocked compound as an oil (0.105g). The oil was dissolved in 1 , 4- dioxane (4mL) and 4N hydrochloric acid was added. The resulting mixture was stirred at room temperature for 18 hours. It was then neutralized with ammonium hydroxide and concentrated. The residue was purified by column chromatography on silica gel with chloroform:methanol:water:ammonium hydroxide (60:30:2:2) to give an oil which was solidified with water to yield the title compound as a tan powder (26mg).

¹H NMR (DMSO -d₆) : δ values include 1.35 (d ), 3.13 (br m), 3.36 (br m, overlapping H₂0), 3.54 (br m), 4.98 (d), 6.13 (br m), 6.36 (d ), 6.87 (s), 7.02 (dd ), 7.27 (m), 7.42 (m), 7.62-7.50 (m), 8.62 (d ).

C₂₁H₂₃CIN₂0₄S: MH+ 435.1148 (error -0.3 ppm) Example 4

7-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- sulfonic acid A suspension of 7-amino - 2 - naphthalene sulfonic acid sodium salt (0.554g) and {2R-(tert-butoxycarbonyl)-[2R-(tert-butyl-dimethyi-silanoxy)-2-(3-chloro-phenyl)- ethyl]-amino}-propionaldehyde (0.500g) in N,N-dimethylformamide (8.1mL) was stirred for ten minutes before the addition of sodium triacetoxyborohydride (0.479g). The mixture was stirred for 18 hours. A 15% aqueous solution of Rochelle's salt was added and the mixture was stirred for one hour. The mixture was then extracted with toluene. The organic layer was dried, filtered, and evaporated to a dark oil, which was purified by chromatography on silica gel with chloroform:methanol:water (60:30:4) to give the blocked product as an oil (0.46g). The oil was dissolved in tetrahydrofuran (4mL) and 6N HCI (4mL) was added. The resulting mixture was stirred at room temperature for two days. It was then neutralized with ammonium hydroxide and concentrated.. The residue was purified by column chromatography on silica gel with chloroform:methanol:water:ammonium hydroxide (60:30:2:2) to give the title compound as an oil. The sample was solidified with ethanohwater to yield a tan powder (63.9mg). HPLC: t_r= 17.54min (to=1.6min).

C₂₁H₂₃CIN₂0₄S: MH+ 435.1163 (error 1.8 ppm)

Example 5

5-{2-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-ethylamino}-naphthalene-2- sulfonic acid

A solution of {2-(tetf-butoxycarbonyl)-[2R-(fett-butyl-dimethyl-silanoxy)-2-(3-chloro- phenyl)-ethyl]-amino}-acetaldehyde (0.32g) and 5-amino - 2 - naphthalene sulfonic acid (0.335g) in N,N-dimethylformamide (5.4mL) was stirred for ten minutes before the addition of sodium triacetoxyborohydride (0.318g). The resulting mixture was stirred for 18 hours. A 15% aqueous solution of Rochelle's salts was then added and the mixture was stirred for an additional hour. The mixture was extracted with toluene. The organic layer was dried (magnesium sulfate),, filtered, and concentrated. The residue was purified by chromatography on silica gel with chloroform:methanol:water (60:30:4) to give the blocked product (0.56g),which was dissolved in tetrahydrofuran (5mL). Following the addition of 6N hydrochloric acid (5mL), the mixture was stirred at room temperature for 18 hours before being evaporated. The residue was purified by column chromatography on silica gel with chloroform:methanol:water:ammonium hydroxide (60:30:2:2) to afford the title compound as a tan powder (73.7mg).

HPLC: t_r= 17.8 min (t₀=1.8min).

C₂₀H₂₁CIN₂O₄S: MH+ 421.0999 (error 1.1 ppm)

Example 6

Methyl 5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate dihydrochloride

Methyl 5-[((2S)-2-(_etf-butoxycarbonyl)[(2R)-2-[fetf-butyl(dimethyl)silyl]oxy-2-(3- chlorophenyl)ethyl]aminopropyl)amino]-2-naphthoate (1.21 g) was covered in a solution of 4N hydrochloric acid in dioxane (9 mL). The mixture was stirred for 2 h and diethyl ether (30 mL) was added. The resulting precipitate was collected by suction filtration and dried en vacuo to afford the title compound (807 mg) as a pale green powder. ¹H NMR (DMSO-d6) : δ values include 1.51(d), 3.99(s), 5.02(dd), 6.88(d), 8.01(d), 8.20(d), 8.53( s).

Electrospray ms (positive ion) (M+H) 413.2

Similarly prepared was: Example 7

Methyl 5-{2S-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate dihydrochloride

Electrospray ms (negative ion) 413/415 from methyl 5-[((2S)-2-(fett-butoxycarbonyl)[(2f?)-2-[.etf-butyl(dimethyl)silyl]oxy-2- (3-chlorophenyl)ethyl]aminopropyl)amino]-2-naphthoate (580 mg).

Example 8

5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- carboxylic acid A solution of 5-{2R-[2-(3-chloro-phenyl)-2R-hydroxy-ethylamino}-naphthalene-2- carboxylic acid methyl ester dihydrochloride (1.55 g) and lithium hydroxide monohydrate (852 mg) in 3:1 methanokwater (20 mL) was stirred for 16 h. The mixture was concentrated to leave a residue which was purified by silica gel chromatography eluting with 46:15:1 chloroform:methanol:ammonium hydroxide to afford, after concentrating the relevant fractions, a yellow powder. Trituration with water and drying under vacuum afforded the title compound (946 mg) as a cream colored powder.

Assay Found: C65.53; H, 5.89; N, 6.91 C₂₂H₂₃N₂0₃CI 0.25 H₂0 requires: C, 65.50; H, 5.87; N, 6.94

Electrospray ms (positive ion) (M+H) 399.3

Similarly prepared was:

Example 9 5-{2S-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-2- carboxylic acid (114 mg),

Assay: Found: C 66.48, H 5.96, N 6.79, Cl 8.72% C22H23N2O3CI requires C 66.24, H 5.81 N 7.02, Cl 8.89%

Electrospray ms (negative ion) (M-H) 399/401 from methyl 5-{2S-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate dihydrochloride (218 mg).

Example 10

6-{2R-[2-(3-Chlorophenyl)-2R-hydroxyethyl]aminopropyl)amino]-naphthalene-2- carboxylic acid

A solution of methyl 6-[((2R)-2-(tert-butoxycarbonyl)[(2S)-2-[tert- butyl(dimethyl)silyl]oxy-2-(3-chlorophenyl)ethyl]aminopropyl)amino]-2-naphthoate (804 mg) in 4 N HCI in dioxane (7 mL) was stirred for 5.5 h under nitrogen. Volatiles were then removed under vacuum, leaving a gummy purple solid, which was redissolved in dioxane/water (10 mL, 5:1). Lithium hydroxide monohydrate (378 mg) was then added, and the pink solution was stirred for 16 h. Volatiles were then removed under vacuum. Portions of methanoi were distilled off under vacuum to remove water, and the resulting orange gum was chromatographed on silica gel, eluting with chloroform/methanol/ammonium hydroxide (80:15:2). Portions of ethanol were distilled under vacuum from the off-white solid so obtained. The resulting material was triturated in water (5 mL) and dried under vacuum to afford the title compound (141 mg) as a white powder.

Assay: Found: C 65.76, H 6.01 , N 6.66, Cl 8.71%

C22H23N2O3CI 0.04 H2O 0.2 C2H6O requires C 65.81 , H 5.99 N 6.85, Cl 8.67% mp: 206-207 °C (dec)

Similarly prepared was:

Example 11

6-{2R-[2-(3-Chlorophenyl)-2R-hydroxyethyl]aminopropyl)amino]-naphthalene-1- carboxylic acid (98 mg),

Assay: Found: C 64.41 , H 6.00, N 6.58, Cl 8.66%

C22H23N2O3CI 0.06 H2O 0.6 C2H6O requires C 64.41, H 6.00, N 6.79, Cl 8.60% mp: 224-226 °C (dec) from methyl 6-[((2R)-2-(fett-butoxycarbonyl)[(2R)-2-[fet.-butyl(dimethyl)silyl]oxy-2-(3- chlorophenyl)ethyl]aminopropyl)amino]-1 -naphthoate (260 mg).

TABLETS FOR ORAL ADMINISTRATION

Tablets may be prepared by the normal methods such as direct compression or wet granulation. The tablets may be film coated with suitable film forming materials, such as hydroxypropyl methylcellulose, using standard techniques. Alternatively the tablets may be sugar coated.

Direct Compression Tablet mg/tablet (i) Active Ingredient 4.68

Calcium Hydrogen Phosphate BP^* 83.06

Croscarmellose Sodium NF 1.8

Magnesium Stearate BP 0.452

Compression weight 90.0 ^* of a grade suitable for direct compression. The active ingredient is passed through a 60 mesh sieve, blended with the calcium hydrogen phosphate, croscarmeliose sodium and magnesium stearate. The resultant mix is compressed into tablets using a Manesty F3 tablet machine fitted with 5.5mm, flat bevelled edge punches. mg/tablet

(ϋ) Active Ingredient. 0.31

Anhydrous Lactose USNF 131.99

Pregelatinised Starch USNF 7.0

Magnesium Stearate BP 0.7

Compression weight 140.0

The active ingredient is passed through a 60 mesh sieve, and blended with the lactose, pregelatinised starch and magnesium stearate. The resultant mix is compressed into tablets using a Manesty F3 tablet machine fitted with 7.5mm normal concave punches.

SYRUP

This may be either a sucrose or sucrose free presentation.

A. Sucrose Syrup mg/5ml dose

Active Ingredient 2.5

Sucrose BP 2750.0

Glycerine BP 500.0

Buffer )

Flavour )

Colour ) as required

Preservative )

Purified Water BP to 5.0ml

The active ingredient, buffer, flavour, colour and preservative are dissolved in some of the water and the glycerine is added. The remainder of the water is heated to dissolve the sucrose and is then cooled. The two solutions are combined, adjusted to volume and mixed. The syrup is clarified by filtration.

B. Sucrose-free Syrup mg/5ml dose

Active Ingredient 2.5

Hydroxypropylmethylcellulose USP viscosity type 4000) 22.5 2?

Buffer )

Flavour )

Colour ) as required

Preservative) Sweetener )

Purified Water BP to 5.0ml

The hydroxypropylmethylcellulose is dispersed in hot water, cooled and then mixed with an aqueous solution containing the active ingredient and the other components of the formulation. The resultant solufion is adjusted to volume and mixed. The syrup is clarified by filtration.

INJECTION FOR INTRAVENOUS ADMINISTRATION yg/m!

(i) Active Ingredient 800 Dilute Hydrochloric Acid BP to pH 3.5

Sodium Chloride Injection BP to 1ml

The active ingredient is dissolved in a suitable volume of Sodium Chloride Injection BP, the pH of the resultant solution is adjusted to pH3.5 with dilute hydrochloric acid BP then the solution is made to volume with sodium chloride injection BP and thoroughly mixed. The solution is filled into Type I clear glass 5ml ampoules which are sealed under a headspace of air, by fusion of the glass then sterilised by autoclaving at 120^ for not less than 15 minutes.

]___[___

(ii) Active ingredient 56.2 Sodium Chloride BP as required

Water for Injection BP to 1.0ml

Sodium chloride may be added to adjust the tonicity of the solution and the pH may be adjusted, using acid or alkali, to that of optimum stability and/or facilitate solution of the active ingredient. Alternatively, suitable buffer salts may be used. The solution is prepared, clarified and filled into appropriate size ampoules sealed by fusion of the glass. The injection is sterilised by heating in an autoclave using one of the acceptable cycles. Alternatively, the solution may be sterilised by filtration and filled into sterile ampoules under aseptic conditions. The solufion may be packed under an inert atmosphere of nitrogen or other suitable gas. SUPPOSITORY FOR RECTAL ADMINISTRATION

Active ingredient 49.0 mg Witepsol^* H15 to 1.0g

*a proprietary grade of Adeps Solidus Ph.Eur. A suspension of the active ingredient in molten Witepsol is prepared and filled using suitable machinery, into 1g size suppository moulds.

BIOLOGICAL RESULTS

The compounds of Examples were tested for beta-3-adrenoceptor activity using above described Method with the following results:

Claims

compound of formula (I)

(I) wherein

The groups N(R3) and R⁴ are separated by at least 4 ring carbon atoms;

R² represents hydrogen or C^alkyl;

R represents hydrogen or C ι_4 alkyl;

R⁴ represents CO2R⁶ or SO3H;

R5 represents one or more groups independently selected from hydrogen, Cη.5 alkyl, halogen, trifluoromethyl and C^alkoxy; n represents an integer from 1-6;

R6 and R⁷ independently represent hydrogen or C-|_4 alkyl; or pharmaceutically acceptable derivatives thereof.

A compound as claimed in claim 1 of formula (la)

wherein

The groups N(R3) and R⁴ are separated by at least 4 ring carbon atoms; Rl represents a phenyl, naphthyl, pyridyl or pyrmidyl group, optionally substituted by one or more substituents selected from halogen, hydroxy, C-j. ρalkoxy, Chalky!, nitro, cyano, hydroxymethyl, trifluoromethyl, NR⁶R⁷, and

NHS0₂R⁶;

R² represents hydrogen or C^alkyl; R³ represents hydrogen or Cι_4 alkyl; R⁴ represents CO2R⁶ or SO3H; R5 represents one or more groups independently selected from hydrogen,

C-|.ρ alkyl, halogen, trifluoromethyl and C^alkoxy; n represents an integer from 1-6;

R6 and R⁷ independently represent hydrogen or C-]_4 alkyl; or pharmaceutically acceptable derivatives thereof. 3. A compound as claimed in claim 1 or 2 where R¹ represents phenyl optionally substituted by one, two or three substituents selected from halogen, hydroxy, C^alkoxy, C^alkyl, nitro, cyano, hydroxymethyl and trifluoromethyl.

4. A compound as claimed in any one of claims 1 to 3 wherein R¹ represents a phenyl group substituted by a chlorine atom located in the meta position. 5. A compound as claimed in any one of claims 1 to 4 wherein R² is methyl or hydrogen.

6. A compound as claimed in any one of claims 1 to 5 where R³ is hydrogen.

7. A compound as claimed in any one of claims 1 to 6 where R⁴ is CO2H.

8. A compound as claimed in claim 1 represented by formula (lb):

where R² represents hydrogen or methyl;

R⁴ represents CO2H or SO3H; or pharmaceuticallyacceptable derivatives thereof.

9. A compound selected from: 6-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene-

2-sulfonic acid; 5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene- 2-sulfonic acid;

6-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}-napthalene- 1 -sulfonic acid; 7-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}- naphthalene-2-sulfonic acid;

5-{2-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-ethylamino}-naphthalene-2- sulfonic acid;

5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}- naphthalene-2-carboxylic acid;

6-{2R-[2-(3-Chlorophenyl)-2R-hydroxy-ethylamino]-propylamino}- naphthalene-2-carboxylic acid;

6-{2R-[2-(3-Chlorophenyl)-2R-hydroxy-ethylamino]-propylamino}- naphthalene-1 -carboxylic acid; 5-{2S-[2-(3-Chlorophenyl)-2R-hydroxy-ethylamino]-propylamino}-naphthalene-

2-carboxylic acid;

Methyl 5-{2S-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate;

Methyl 5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino}-2-naphthoate; and pharmaceutically acceptable derivatives thereof. 10. 5-{2R-[2-(3-Chloro-phenyl)-2R-hydroxy-ethylamino]-propylamino}- naphthalene-2-carboxylic acid; and pharmaceutically acceptable derivatives thereof.

11. A compound according to any one of Claims 1 to 10 for use in therapy.

12. A method of treatment of a mammal, including man, suffering from a condition susceptible of amelioration by an atypical beta-adrenoceptor agonist comprising administration of an effective amount of a compound according to any one of claims 1 to 10 or a pharmaceutically acceptable derivative thereof.

13. The use of a compound according to any one of claims 1 to 10 or a pharmaceuticallyacceptable derivative thereof, for the manufacture of a medicament for the treatment of a condition susceptible of amelioration by an atypical beta-adrenoceptor agonist.

14. A pharmaceufical composifion comprising a compound according to any one of claims 1 to 10 or a pharmaceuticallyacceptable derivative thereof together with one or more pharmaceutically acceptable carriers.

15. A pharmaceutical composition which comprises a compound according to any one of claims 1 to 10 and a non-steroidal anti-Inflammatory drug, together with one or more pharmaceutically acceptable carriers.

16. A process for preparing a compound of formula (I) as claimed in claim 1, or a pharmaceutically acceptable derivative thereof, which comprises:

(A) reaction of a compound of formula (II):

where p1 and P² are suitable protecting groups for oxygen and nitrogen groups respectively, R⁴ is CO2R⁶ or SO3H and R⁶ is C<|_6 alkyl, by deprotection of pi and P² under suitable conditions; or

(B) reaction of a compound of formula (I) to give a different compound of formula (I); or

(C) reaction of a compound of formula (III) with a compound of formula (IV)

where P¹ and P² are suitable protecting groups for oxygen and nitrogen groups respectively, R⁴ is CO2R⁶ or SO3H and R⁶ is C_π_6 alkyl, followed by deprotection of any protecting groups, without purification of the intermediate product.