compounds of formula ( i ) for use in the invention include ( but are not limited to ) novel compounds such as : it is understood that the invention refers to salts , e . g . the hydrochloride of compounds ( i ). the compounds may also be provided as metabolites and pro - drugs thereof . the compounds are chiral , and the invention includes substantially single diastereomers and enantiomers of ( i ). aryl and heteroaryl groups are know , and typically have up to 12 atoms . the compounds of formula ( i ) according to the invention are used to treat inflammatory diseases including , but not exclusive to , autoimmune diseases involving multiple organs , such as systemic lupus erythematosus ( sle ) and scleroderma , specific tissues or organs such as the musculoskeletal tissue ( rheumatoid arthritis , ankylosing spondylitis ), gastro - intestinal tract , ( crohn &# 39 ; s disease and ulcerative colitis ), the central nervous system ( alzheimers , multiple sclerosis , motor neurone disease , parkinson &# 39 ; s disease and chronic fatigue syndrome ), pancreatic beta cells ( insulin dependent diabetes mellitus ), the adrenal gland ( addison &# 39 ; s diseae ), the kidney ( goodpasture &# 39 ; s syndrome , iga nephropathy , interstitial nephritis ) exocrine glands ( sjogrens syndrome and autoimmune pancreatitis ) and skin ( psoriasis and atopic dermatitis ), chronic inflammatory diseases such as osteoarthritis , periodontal disease , diabetic nephropathy , chronic obstructive pulmonary disease , artherosclerosis , graft versus host disease , chronic pelvic inflammatory disease , endometriosis , chronic hepatitis and tuberculosis , ige mediated ( type i ) hypersensitivities such as rhinitis , asthma , anaphylaxis , dermatitis and ophthalmic conditions . dermatitis conditions include ; actinic keratosis , acne rosacea , acne vulgaris , allergic contact dermatitis , angioedema , atopic dermatitis , bullous pemiphigoid , cutaneous drug reactions , erythema multiforme , lupus erythrametosus , photodermatitis , psoriasis , psoriatic arthritis , scleroderma and urticaria . opthalmic conditions include age related macular degeneration , diabetic retinopathy , choroidal neovascular membrane , cystoid macular edema , epi - retinal membrane , macular hole , dry eye and uveitis . these compounds may be used according to the invention when the patient is also administered or in combination with another therapeutic agent selected from corticosteroids ( examples including cortisol , cortisone , hydrocortisone , dihydrocortisone , fludrocortisone , prednisone , prednisolone , deflazacort , flunisolide , beconase , methylprednisolone , triamcinolone , betamethasone , and dexamethasone ), disease modifying anti - rheumatic drugs ( dmards ) ( examples including , azulfidine , aurothiomalate , bucillamine , chlorambucil , cyclophosphamide , leflunomide , methotrexate , mizoribine , penicillamine and sulphasalazine ), immunosuppressants ( examples including azathioprine , cyclosporin , mycophenolate ,) cox inhibitors ( examples including aceclofenac , acemetacin , alcofenac , alminoprofen , aloxipirin , amfenac , aminophenazone , antraphenine , aspirin , azapropazone , benorilate , benoxaprofen , benzydamine , butibufen , celecoxib , chlorthenoxacine , choline salicylate , chlometacin , dexketoprofen , diclofenac , diflunisal , emorfazone , epirizole , etodolac , feclobuzone , felbinac , fenbufen , fenclofenac , flurbiprofen , glafenine , hydroxylethyl salicylate , ibuprofen , indometacin , indoprofen , ketoprofen , ketorolac , lactyl phenetidin , loxoprofen , mefenamic acid , metamizole , mofebutazone , mofezolac , nabumetone , naproxen , nifenazone , oxametacin , phenacetin , pipebuzone , pranoprofen , propyphenazone , proquazone , rofecoxib , salicylamide , salsalate , sulindac , suprofen , tiaramide , tinoridine , tolfenamic acid , zomepirac ) neutralising antibodies ( examples including , etanercept and infliximab ), antibiotics ( examples including , doxycycline and minocycline ). compounds of formula ( i ) exhibit analgesic activity in animal models . the activity of these compounds may be determined by the use of the appropriate in vivo assay . this invention also relates to a method of treatment for patients ( including man and / or mammalian animals raised in the dairy , meat or fur industries or as pets ) suffering from chronic , acute or neuropathic pain ; and more specifically , a method of treatment involving the administration of the analgesic of formula ( i ) as the active constituent . accordingly , the compounds of formula ( i ) can be used among other things in the treatment of pain conditions such as acute and chronic pain ( as well as , but not limited to , pain associated with cancer , surgery , arthritis , dental surgery , trauma , musculo - skeletal injury or disease , visceral diseases ) and migraine headache . additionally the painful conditions can be neuropathic ( post - herpetic neuralgia , diabetic neuropathy , drug induced neuropathy , hiv mediated neuropathy , sympathetic reflex dystrophy or causalgia , fibromyalgia , myofacial pain , entrapment neuropathy , phantom limb pain , trigeminal neuralgia . neuropathic conditions include central pain related to stroke , multiple sclerosis , spinal cord injury , arachnoiditis , neoplasms , syringomyelia , parkinson &# 39 ; s and epilepsia . it will often be advantageous to use compounds of formula ( i ) in combination with another drug used for pain therapy . such another drug may be an opiate or a non - opiate such as baclofen . especially for the treatment of neuropathic pain , coadministration with gabapentin is preferred . other compounds that may be used include acetaminophen , a non - steroidal anti - inflammatory drug , a narcotic analgesic , a local anaesthetic , an nmda antagonist , a neuroleptic agent , an anti - convulsant , an anti - spasmodic , an anti - depressant or a muscle relaxant . any suitable route of administration can be used . for example , any of oral , topical , parenteral , ocular , rectal , vaginal , inhalation , buccal , sublingual and intranasal delivery routes may be suitable . the dose of the active agent will depend on the nature and degree of the condition , the age and condition of the patient and other factors known to those skilled in the art . a typical dose is 1 . 0 - 100 mg given one to three times per day . the compounds of the invention may be prepared via a multistep synthetic route of a type familiar to those skilled in the art , and it is assumed that functional groups present in the molecules can be protected and deprotected as needed . the synthesis begins with a substituted acetophenone or analogue which is reacted initially with bromine to give the bromo derivative , and then the amino alcohol to generate the target molecule . the final compounds are generally isolated via precipitation which may require purification via a technique such as recrystallisation . bromine ( 63 ml , 1 . 22 mol ) was added to a mixture of 4 - amino - 3 , 5 - dichloroacetophenone ( 1 ) ( 250 g , 1 . 22 mol ) in chcl 3 ( 3 l ml ) at room temperature . the mixture was stirred for 1 h then etoh ( 500 ml ) was added . the mixture was cooled to 0 ° c . and stirred for 1 h . the precipitate was filtered and air - dried ( 4 . 7 g , 67 %). 1 h nmr ( 400 mhz , dmso ): 4 . 77 ( 2h , s ), 6 . 61 ( 2h , bs ), 7 . 86 ( 2h , s ); 13 c nmr ( 100 mhz , dmso ): 63 . 39 , 117 . 89 , 128 . 57 , 129 . 75 , 146 . 17 , 195 . 99 . 2 - amino - 2 - methyl - propan - 1 - ol ( 180 ml , 2 . 49 mol ) was added to a mixture of bromo -(- 4 - amino - 3 , 5 - dichloro ) acetophenone ( 2 ) ( 237 g , 0 . 83 mol ) in chloroform ( 650 ml ). the mixture was stirred at room temperature for 2 h , then water ( 380 ml ) was added . the mixture was stirred for 1 h , and then the solid was filtered . the solid was triturated with water ( 1 l ) to give the desired compound ( 3 ) ( 223 g , 91 %). 1 h nmr ( 400 mhz , dmso ): 0 . 94 ( 6h , s ), 3 . 18 ( 2h , d j = 4 . 4 hz ), 3 . 93 ( 2h , s ), 4 . 55 ( 1h , m ), 6 . 40 ( 2h , s ), 7 . 84 ( 2h , s ); 13 c nmr ( 100 mhz , dmso ): 24 . 21 , 48 . 87 , 53 . 73 , 68 . 52 , 117 . 92 , 124 . 57 , 125 . 79 , 128 . 62 , 146 . 07 , 195 . 30 ; lc - ms : 291 , 292 , 293 ( m + h + ). bromine ( 6 . 07 ml , 0 . 12 mol ) was added to a solution of 3 ′- chloropropiophenone ( 20 g , 0 . 12 mol ) in chloroform ( 250 ml ) at room temperature . the reaction was followed by tlc in dcm . when all of the starting material was consumed the mixture was washed with a saturated solution of sodium bicarbonate . the organic phase was dried over magnesium sulphate , filtered and evaporated . recrystallisation from chloroform gives the desired compound in 60 % yield as a pale yellow solid ( 18 g , 73 mmol ). 1 h nmr ( 400 mhz , cdcl 3 ): 7 . 99 ( 1h , m ), 7 . 89 ( 1h , m ), 7 . 55 ( 1h , m ), 7 . 43 ( m ), 5 . 21 ( 1h , q j = 6 . 5hz ), 1 . 9 ( 3h , j = 6 . 5hz ) 2 - amino - 1 - methyl - propan - 1 - ol ( 14 ml , 0 . 15 mol ) was added to α - bromo - 3 ′ chloro propiophenone ( 18 g , 73 mmol ) in suspension in chloroform ( 50 ml ), with two crystals of sodium iodide . the reaction was heated under reflux overnight . after filtration the organic phase was extracted twice with a 2m hcl solution ( 2 × 100 ml ). the aqueous phase wash washed with dcm then neutralised with sodium carbonate . the aqueous layer was extracted with dcm . the organic phase was dried over magnesium sulphate , filtered and evaporated . recrystallisation from chloroform gives the desired compound in 55 % yield as a white solid ( 10 . 2 g , 40 mmol ). 1 h nmr ( 400 mhz , cdcl 3 ): 7 . 57 ( 1h , m ), 7 . 27 - 7 . 26 ( 2h , m ), 3 . 77 - 3 . 74 ( 1h , m ), 3 . 37 - 3 . 34 ( 1h , m ), 3 . 14 - 3 . 11 ( 1h , m ), 1 . 37 ( 3h , s ), 1 . 04 ( 3h , s ), 0 . 76 ( 3h , s ). 13 c nmr ( 100 mhz , chcl 3 ): 16 . 23 , 22 . 69 , 27 . 06 , 49 . 85 , 53 . 41 , 69 . 33 , 95 . 91 , 124 . 52 , 126 . 62 , 128 . 04 , 129 . 34 , 134 . 05 , 144 . 11 . lc - ms : 256 ( m + h + ). guinea - pig trachea ring preparations were suspended in kreb &# 39 ; s solution containing indomethacin . after 15 minutes stabilisation , the preparations were repeated contracted using carbachol and simultaneously treated with increasing cumulative doses test compounds ( 0 . 1 nm to 0 . 1 μm ). beta2 agonism for each test compound was determined by its dose dependant inhibition of carbachol stimulated tracheal muscle twitch . compound ( 3 ) was a very poor beta2 agonist , with an ic50 of 13 μm . 7 week old balb c byj mice ( 24 - 28 g ) were administered , either by i . p . ( 5 ml / kg ) or oral ( 10 ml / kg ) administration , with vehicle or test article . 30 minutes later these animals were challenged with an intraperitoneal injection of 1 mg / kg lps . 2 hours after lps challenge blood samples were collected under light isoflurane anaesthesia into normal tubes by retro - orbital puncture . samples were allowed to clot at room temperature and then spun at 6000 g for 3 min at 4 ° c . serum was stored at − 20 ° c . until use . serum tnfα and il - 10 levels were analysed in duplicate by elisa technique . compound ( 3 ) had strong inhibitory effects on tnfα and potentiating effects on il - 10 . these effects are unlikely to be due to beta2 agonism . fasted ( 18 hour ) male wistar rats ( 105 - 130 g ) were weighed and a basal mercury plethysmometer reading was taken of the right hind paw by submerging the paw in the mercury up to the tibiotarsal joint . subsequently , vehicles , reference items and test articles were administered by oral gavage ( 10 ml / kg ). half an hour after treatment 0 . 1 ml of 2 % carrageenan in 0 . 9 % saline was injected into the subplanatar area of the right hind paw . the right paw was measured again with the plethysmometer at 1 , 2 , 3 , 4 and 5 hours after carrageenan administration . compound ( 3 ) had a dose - dependant inhibitory effect on inflammation induced by carrageenan paw injection .
a compound for therapeutic use , of the formula wherein r 1 is aryl or heteroaryl optionally substituted with r 5 ; r 2 is h , alkyl or ch 2 oh or forms part of a ring with r 4 ; r 3 is h , alkyl or ch 2 oh or forms part of a ring with r 4 ; r 4 is h , alkyl or ch 2 ; and r 5 is alkyl , cf 3 , oh , oalkyl , ocoalkyl , conh 2 , cn , halogen , nh 2 , no 2 , nhcho , nhconh 2 , nhso 2 me , conh 2 , or some ; or a salt thereof .