Kinase inhibitors

Abstract

There are provided compounds of formula (I), wherein R 1 to R 5 , X 1 , X 2 , Ar, L, E, A, A 1 , G and G 1 have meanings given in the description, which compounds have anti-inflammatory activity (e.g. through inhibition of one or more of members of: the family of p38 mitogen-activated protein kinase enzymes; Syk kinase; and members of the Src family of tyrosine kinases) and have use in therapy, including in pharmaceutical combinations, especially in the treatment of inflammatory diseases, including inflammatory diseases of the lung, eye and intestines.

1 . A compound of formula I, 
       
         
           
           
               
               
           
         
       
       wherein
 R 1  represents H or C 1-3  alkyl; 
 R 2  and R 3  independently represent H or C 1-3  alkyl, or R 2  and R 3  together combine to form C 2-3  alkylene; 
 X 1  and X 2  are both N, or X 1  is C and X 2  is either O or S; 
 Ar is phenyl or a 5- or 6-membered heteroaryl group containing one or more heteroatoms selected from the group consisting of N, O and S, which phenyl and heteroaryl groups are optionally substituted by one or more substituents selected from the group consisting of halo, C 1-4  alkyl, C 1-4  haloalkyl, C 1-4  alkoxy, hydroxy, amino and cyano; 
 L is a direct bond or C 1-2  alkylene; 
 E represents:
 (a) H, halo, hydroxy, NR 6a R 6b , cyano, C(O)OR 6c , C(O)NR 6d R 6e , SH, S(O) n R 8 , S(O) 2 NR 6f R 6g , 
 (b) C 1-8  alkyl, C 2-8  alkenyl, C 2-8  alkynyl, C 1-8  alkoxy, which latter four groups are optionally substituted by one or more substituents selected from the group consisting of halo and NR 7a R 7b , 
 (c) C 3-8  cycloalkyl, Het 1  or Ar 1 , which latter three groups are optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy and C 1-3  alkyl; 
 
 R 6a  to R 6g  independently represent H or C 1-4  alkyl, or 
 any one or more of the pairs R 6a  and R 6b , R 6d  and R 6 , and R 6f  and R 6g , when taken together with the N-atom to which each pair is attached, form a saturated 4- to 7-membered heterocyclic group, which heterocyclic group contains one N atom (the atom to which the pairs of substituents are attached) and, optionally, one or more further heteroatoms selected from the group consisting of O, S and N, and which heterocyclic group is optionally substituted by one or more C 1-2  alkyl groups; 
 R 7a  and R 7b , independently on each occurrence, represent H or C 1-4  alkyl, or, together with the N-atom to which they are attached, form a 5- to 7-membered heterocyclic group that is fully saturated, partially unsaturated or fully aromatic and which heterocyclic group contains one N atom (the atom to which R 7a  and R 7b  are attached) and, optionally, one or more further heteroatoms selected from the group consisting of O, S and N, and which heterocyclic group is optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, oxo, C 1-4  alkyl and C 1-4  alkoxy; 
 R 8  represents C 1-4  haloalkyl, C 1-4  alkyl, C 3-8  cycloalkyl or Ar 2 , which latter three groups are optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy and C 1-3  alkyl; 
 Ar 1  and Ar 2  independently represent C 6-14  carbocyclic aryl groups, which groups may be monocyclic, bicyclic or tricyclic and which groups contain at least one ring which is fully aromatic, 
 n is 0, 1 or 2; 
 R 4  and R 5  are each independently C 1-3  alkyl, C 1-3  haloalkyl, cyano or halo, 
 or R 4  and R 5  together combine to form C 3-5  alkylene or C 3-5  alkenylene, which latter two groups are optionally substituted by one or more substituents selected from the group consisting of C 1-3  alkyl, C 1-3  haloalkyl, cyano and halo, 
 or R 4  and R 5 , together with the C-atoms to which they are attached, form a fused phenyl or Het 2  ring, which latter two rings are optionally substituted by one or more substituents selected from the group consisting of C 1-3  alkyl, C 1-3  haloalkyl, cyano and halo; 
 Het 1  and Het 2  independently represent 5- to 7-membered heterocyclic groups that are fully saturated, partially unsaturated or fully aromatic, which heterocyclic groups contain one or more heteroatoms selected from the group consisting of N, O and S; 
 one of A and A 1  represents N and the other represents CH, or both of A and A 1  represent CH; 
 G represents
 phenyl optionally substituted by one or more Y 1  or 
 Het 3  optionally substituted by one or more Y 2 ; 
 
 G 1  represents H; 
 or G and G 1  together combine to form C 3-6  alkylene optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy and C 1-3  alkyl, which latter group is optionally substituted by one or more halo atoms or by hydroxy; 
 each Y 1  is independently selected from the group consisting of:
 halo, hydroxy, cyano, SF 5 , —OC(O)NH 2 , 
 P(O)R 9a R 9b , 
 J 1 -N(R 9c )R 9d , 
 J 2 -S(O) 2 R 9e , 
 J 3 -[CH 2 (CH 2 ) 0-1  CH 2 —O] 2-8 —R 9f , 
 —C≡C—R 9g , 
 —N═S(O)R 9h R 9i , 
 Het a , and 
 C 1-6  alkyl, C 3-6  cycloalkyl, C 1-6  alkoxy, C 3-6  cycloalkoxy, —S(O) 0-1 —C 1-6  alkyl and —S(O) 0-1 —C 3-6  cycloalkyl which latter six groups are optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, C 1-3  alkyl, C 1-3  alkoxy and C 3-6  cycloalkyl; 
 
 each Y 2  independently represents oxo or Y 1 ; 
 J 1  represents
 a direct bond, 
 —C(O)— 
 —[C(O)] p —C 1-8  alkylene, 
 —C(O)NR 10a —CH 2 —[C 1-7  alkylene]-, 
 -Q 1 -CH 2 —[C 1-5  alkylene]-, 
 the alkylene parts of which latter four groups are optionally substituted by one or more substituents selected from the group consisting of halo, C 1-3  alkyl and hydroxy; 
 
 J 2  represents
 a direct bond, 
 —O—, 
 —NH— 
 C 1-6  alkylene or 
 -Q 2 -CH 2 —[C 1-5  alkylene]-, 
 the alkylene parts of which latter two groups are optionally substituted by one or more substituents selected from the group consisting of halo, C 1-3  alkyl and hydroxy; 
 
 J 3  represents —O— or S(O) 0-2 ; 
 Q 1  and Q 2  independently represent O or S(O) 0-2 ; 
 p represents 0 or 1; 
 R 9a  and R 9b  independently represent C 1-3  alkyl or C 1-3  alkoxy, or R 9a  and R 9b  together combine to form C 4-6  alkylene; 
 R 9c  and R 9d  independently represent H or C 1-8  alkyl, which latter group is optionally substituted by R 10b  and/or one or more substituents selected from the group consisting of halo and hydroxy; or 
 R 9c  and R 9d , together with the N-atom to which they are attached, form a 4- to 7-membered heterocyclic group that is fully saturated, partially unsaturated or fully aromatic and which heterocyclic group contains one N atom (the atom to which R 9c  and R 9d  are attached) and, optionally, one or more further heteroatoms selected from the group consisting of O, S and N, and which heterocyclic group is optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, oxo, C 1-4  alkyl and C 1-4  alkoxy; 
 R 9e  represents C 1-6  alkyl, C 3-6  cycloalkyl or phenyl, which latter three groups are optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, C 1-3  alkyl, C 1-3  alkoxy and C 3-6  cycloalkyl; 
 R 9f , R 9g , R 9h  and R 9i  independently represent C 1-4  alkyl optionally substituted by one or more halo atoms, or R 9f  and R 9g  independently represent H; 
 R 10a  represents H or C 1-3  alkyl optionally substituted by one or more halo atoms; 
 R 10b  represents C 1-4  alkoxy, S—C 1-4  alkyl, phenyl or Het 4 , which latter two groups are optionally substituted by one or more substituents selected from the group consisting of halo, C 1-4  alkyl, C 1-4  haloalkyl, C 1-4  alkoxy, hydroxy, amino and cyano; 
 Het 3  represents a 5- to 10-membered heteroaromatic group, which group is monocyclic or bicyclic and contains at least one carbocyclic or heterocyclic ring that is fully aromatic, and which group contains one or more heteroatoms selected from the group consisting of N, O and S; 
 Het 4  represents a 4- to 10-membered heterocyclic group that is fully saturated, partially unsaturated or fully aromatic, which heterocyclic group contains one or more heteroatoms selected from the group consisting of N, O and S; 
 Het a  represents a 5- or 6-membered heterocyclic group that is fully saturated, partially unsaturated or fully aromatic, which group contains one or more heteroatoms selected from the group consisting of N, O and S, and which group is optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, C 1-3  alkyl, C 1-3  alkoxy and C 3-6  cycloalkyl, 
 
       or a pharmaceutically acceptable salt, solvate or isotopic derivative thereof. 
     
     
         2 . A compound as claimed in  claim 1  which is a compound of formula Ia, 
       
         
           
           
               
               
           
         
       
       wherein
 R 1  represents H or C 1-2  alkyl; 
 R 2  and R 3  independently represent H or C 1-2  alkyl, or R 2  and R 3  together combine to form C 2  alkylene; 
 A represents CH or N; 
 A 2  represents CH or N; 
 R 4  and R 5  are both halo, 
 or R 4  and R 5 , together with the C-atoms to which they are attached, form a fused phenyl ring; 
 R a  represents C 1-2  alkyl or C 1-2  alkoxy, which latter two groups are optionally substituted by one or more halo atoms, or R a  represents C 1-2  alkyl or C 2  alkoxy, which latter two groups are substituted by NR 7a R 7b ; 
 R 7a  and R 7b  both represent C 1-2  alkyl or, together with the N-atom to which they are attached, form a 5- or 6-membered heterocyclic group that is fully saturated and which heterocyclic group contains one N atom (the atom to which R 7a  and R 7b  are attached) and, optionally, one further heteroatom selected from the group consisting of O, S and N, and which heterocyclic group is optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, oxo, C 1-4  alkyl and C 1-4  alkoxy; 
 A 3  and A 4  both represent CH, or one of A 3  and A 4  represents N and the other represents CH; 
 R b , R c  and R d  independently represent H, halo, hydroxy, —C≡C—H, C 1-4  alkylene-N(R 9c )R 9d , —C(O)NH—CH 2 —[C 1-3  alkylene]-N(R 9c )R 9d , -Q 1 -CH 2 —[C 1-3  alkylene]-N(R 9c )R 9d , —O—[CH 2 CH 2 O] 2-7 —R 9f , C 1-4  alkyl, C 1-4  alkoxy or C(O)NHC 1-4  alkyl, which latter three groups are optionally substituted by one or more halo atoms, 
 or R b  and R c , together with the C-atoms to which they are attached, form a fused, 5- or 6-membered heteroaromatic or heterocyclic ring, which ring:
 (i) contains one to three heteroatoms selected from the group consisting of N, O and S; and 
 (ii) is optionally substituted by one or more substituents selected from the group consisting of H, halo, hydroxy, oxo, amino, C 1-2  alkyl and C 1-2  alkoxy, which latter two groups are optionally substituted by one or more halo atoms; 
 
 R 9c  and R 9d  both represent C 1-2  alkyl or, together with the N-atom to which they are attached, form a 5- or 6-membered heterocyclic group that is fully saturated and which heterocyclic group contains one N atom (the atom to which R 9c  and R 9d  are attached) and, optionally, one further heteroatom selected from the group consisting of O, S and N, and which heterocyclic group is optionally substituted by one or more substituents selected from the group consisting of halo, hydroxy, oxo, C 1-4  alkyl and C 1-4  alkoxy; and 
 R 9f  represents H or methyl, 
 
       or a pharmaceutically acceptable salt, solvate or isotopic derivative thereof. 
     
     
         3 . A compound as claimed in  claim 2 , which is a compound of formula Ib, 
       
         
           
           
               
               
           
         
         or a pharmaceutically acceptable salt, solvate or isotopic derivative thereof, 
         wherein R 1  to R 5 , A, A 2 , A 3 , A 4  and R a  to R d  are as defined in  claim 2 . 
       
     
     
         4 . A compound as claimed in  claim 2  which is a compound of formula Ic, Id or Ie, 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
       
       or a pharmaceutically acceptable salt, solvate or isotopic derivative thereof, 
       wherein:
 R 1  to R 5 , A, A 2  and 
 R a  are as defined in  claim 2 ; 
 R c2  and R d2  are as defined above for R c  and R d  in  claim 2 ; 
 R d1  is as defined above for R d  in  claim 2 ; and 
 A x  represents CH or N. 
 
     
     
         5 . A compound as claimed in  claim 2 , wherein R 1  is H and R 2  and R 3  both represent methyl. 
     
     
         6 . A compound as claimed in  claim 2 , wherein A 2  represents CH. 
     
     
         7 . A compound as claimed in  claim 2 , wherein R a  represents methyl. 
     
     
         8 . A compound as claimed in  claim 4 , wherein R d1  represents H or methyl. 
     
     
         9 . A compound as claimed in  claim 4 , wherein:
 (i) R c2  represents H and R d2  represents —O—[CH 2 CH 2 O] 2-7 —CH 3 , —C(O)NH—CH 2 CH 2 —N(R 9c )R 9d  or —O—CH 2 CH 2 —N(R 9c )R 9d ,   (ii) both of R c2  and R d2  represent H, or   (iii) R c2  represents CH 3 , —C≡C—H, —CF 3 , —OCF 3  or —OCH 3  and R d2  represents —O—[CH 2 CH 2 O] 2-7 —CH 3 , —C(O)NH—CH 2 CH 2 —N(R 9c )R 9d  or —O—CH 2 CH 2 —N(R 9c )R 9d .   
     
     
         10 . A compound as claimed in  claim 1 , wherein NR 9c R 9d  represents dimethylamino or morpholin-4-yl. 
     
     
         11 . A compound as claimed in  claim 1 , wherein R 4  and R 5 , together with the C-atoms to which they are attached, form a fused phenyl ring. 
     
     
         12 . A compound as claimed in  claim 1 , which compound is selected from the group consisting of:
 1-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)-3-(4-((2-(phenylamino)pyrimidin-4-yl)oxy)naphthalen-1-yl)urea;   1-(4-((2-((7-methyl-1H-indazol-5-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   1-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)-3-(4-((2-((2-oxoindolin-6-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)urea;   3-methoxy-5-((4-((4-(3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)ureido)naphthalen-1-yl)oxy)pyrimidin-2-yl)amino)-N-(2-morpholinoethyl)benzamide;   1-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)-3-(4-((2-((3-(2-morpholinoethoxy)phenyl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)urea;   1-(4-((2-((3-(2-(dimethylamino)ethoxy)phenyl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   1-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)-3-(4-((2-(phenylamino)pyridin-4-yl)oxy)naphthalen-1-yl)urea;   1-(4-((2-((3-methoxy-5-(2-morpholinoethoxyl)phenyl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   1-(2,3-dichloro-4-((2-((7-methyl-1H-indazol-5-yl)amino)pyrimidin-4-yl)oxy)phenyl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   1-(4-((2-((6-(2-(dimethylamino)ethoxy)pyridin-2-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   1-(4-((2-((4-(2-(dimethylamino)ethoxy)pyridin-2-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   3-((4-((4-(3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)ureido)naphthalen-1-yl)oxy)pyrimidin-2-yl)amino)-N-(2-morpholinoethyl)-5-(trifluoromethyl)benzamide;   1-(4-((2-((3-methoxy-5-(2-(2-(2-methoxyethoxyl)ethoxy)ethoxy)phenyl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea;   3-((4-((4-(3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)ureido)naphthalen-1-yl)oxy)pyrimidin-2-yl)amino)-N-(2-morpholinoethyl)-5-(trifluoromethoxy)benzamide;   3-ethynyl-5-((4-((4-(3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)ureido) naphthalen-1-yl)oxy)pyrimidin-2-yl)amino)-N-(2-morpholinoethyl)benzamide;   1-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)-3-(4-((2-((6-(2-morpholinoethoxy) pyridin-2-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)urea; and   1-(4-((2-((6-(2-(2-(2-methoxyethoxyl)ethoxy)ethoxy)pyridin-2-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea, or a pharmaceutically acceptable salt, solvate or isotopic derivative thereof.   
     
     
         13 . A compound as claimed in  claim 1 , which compound is selected from the group consisting of:
 1-(4-((2-((7-methyl-1H-indazol-5-yl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea; and   1-(4-((2-((3-methoxy-5-(2-(2-(2-methoxyethoxyl)ethoxy)ethoxy)phenyl)amino)pyrimidin-4-yl)oxy)naphthalen-1-yl)-3-(3-(2-methylbut-3-yn-2-yl)-1-(p-tolyl)-1H-pyrazol-5-yl)urea,   
       or a pharmaceutically acceptable salt, solvate or isotopic derivative thereof. 
     
     
         14 . A pharmaceutical formulation comprising a compound as defined in  claim 1 , or pharmaceutically acceptable salt, solvate or isotopic derivative thereof, in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier. 
     
     
         15 . A combination product comprising
 (A) a compound as defined in  claim 1 , or pharmaceutically acceptable salt, solvate or isotopic derivative thereof, and   (B) another therapeutic agent,   
       wherein each of components (A) and (B) is formulated in admixture with a pharmaceutically-acceptable adjuvant, diluent or carrier. 
     
     
         16 .- 18 . (canceled) 
     
     
         19 . A method of treating or preventing an inflammatory disease, said method comprising administering to a subject an effective amount of
 a compound as defined in  claim 1 .   
     
     
         20 . A method according to  claim 19 , wherein the inflammatory disease is selected from the group consisting of cystic fibrosis, pulmonary hypertension, lung sarcoidosis, idiopathic pulmonary fibrosis, Chronic Obstructive Pulmonary Disease (COPD) (including chronic bronchitis and emphysema), asthma, paediatric asthma, atopic dermatitis, allergic dermatitis, contact dermatitis or psoriasis, allergic rhinitis, rhinitis, sinusitis, conjunctivitis, allergic conjunctivitis, keratoconjunctivitis sicca (dry eye), glaucoma, diabetic retinopathy, macular oedema (including diabetic macular oedema), central retinal vein occlusion (CRVO), dry and/or wet age related macular degeneration (AMD), post-operative cataract inflammation, uveitis (including posterior, anterior and pan uveitis), corneal graft and limbal cell transplant rejection, gluten sensitive enteropathy (coeliac disease), eosinophilic esophagitis, intestinal graft versus host disease, Crohn's disease and ulcerative colitis. 
     
     
         21 . The method according to  claim 19 , wherein the inflammatory disease is asthma or COPD. 
     
     
         22 . The method according to  claim 19 , wherein the inflammatory disease is uveitis, Crohn's disease or ulcerative colitis. 
     
     
         23 . A process for the preparation of a compound of formula I which process comprises:
 (a) reaction of a compound of formula II,   
       
         
           
           
               
               
           
         
         with a compound of formula III, 
       
       
         
           
           
               
               
           
         
         wherein one of Z 1  and Z 2  is a structural fragment of formula IV 
       
       
         
           
           
               
               
           
         
         and the other of Z 1  and Z 2  is a structural fragment of formula V 
       
       
         
           
           
               
               
           
         
         where E, L, Ar, X 1 , X 2 , R 1  to R 5 , A, A 1 , G and G 1  are as defined in  claim 1 ; 
         (b) reaction of a compound of formula IIa, 
       
       
         
           
           
               
               
           
         
         wherein Z 1  is as defined above, with a suitable azide-forming agent,
 which reaction is followed, without isolation, by thermal rearrangement of the intermediate acyl azide (of formula Z 1 —C(O)—N 3 ) to provide, in situ, a compound of formula II, which compound is then reacted with a compound of formula III as defined above; 
 
         (c) reaction of a compound of formula IIb, 
       
       
         
           
           
               
               
           
         
         wherein LG 1  represents a leaving group and Z 1  is as defined above, with a compound of formula III, as defined above; 
         (d) reaction of a compound of formula VI, 
       
       
         
           
           
               
               
           
         
         wherein LG 2  represents a leaving group and E, L, Ar, X 1 , X 2 , R 1  to R 5 , A and A 1  are as defined in  claim 1 , with a compound of formula VII, 
       
       
         
           
           
               
               
           
         
         wherein G and G 1  are as defined in  claim 1 ; or 
         (e) deprotection of an protected derivative of a compound of formula I, wherein the protected derivative bears a protecting group on an O- or N-atom of the compound of formula I. 
       
     
     
         24 . A compound of formula II, IIa or IIb as defined in  claim 23 , wherein Z 1  is a structural fragment of formula IV, as defined in  claim 23 , or a salt or protected derivative of said compound of formula II, IIa or IIb. 
     
     
         25 . A compound of formula III, as defined in  claim 23 , wherein Z 2  is a structural fragment of formula IV, as defined in  claim 23 , or a salt or protected derivative of said compound of formula III. 
     
     
         26 . A compound of formula VI, as defined in  claim 23 , or a salt or protected derivative thereof. 
     
     
         27 . A process for the preparation of a compound of formula XXV, 
       
         
           
           
               
               
           
         
       
       wherein R s1  to R s3  independently represent C 1-4  alkyl and R 2  and R 3  are as defined in  claim 1 , said process comprising the steps of:
 (i) reaction of a compound of formula XXVI 
 
       
         
           
           
               
               
           
         
         
           wherein R s1  to R s3  are as defined above and R 2  and R 3  are as defined in  claim 1 , and Hal represents a halogen selected from the group consisting of Cl, Br and I, with carbon dioxide; and 
         
         (ii) acidification of the resulting carboxylic acid salt. 
       
     
     
         28 . A process according to  claim 27 , wherein the process comprises the steps of:
 (ia) reaction of a compound of formula XXVII,   
       
         
           
           
               
               
           
         
         
           wherein R s1  to R s3  and Hal are as defined in  claim 27  and R 2  and R 3  are as defined in  claim 1 , with magnesium metal; 
         
         (ib) reaction of the resulting compound of formula XXVI with carbon dioxide; and 
         (ii) acidification of the resulting carboxylic acid salt. 
       
     
     
         29 . A process according to  claim 28 , wherein the compound of formula XXVII is reacted with carbon dioxide without isolation from the reaction mixture in which it is formed. 
     
     
         30 . A process according to  claim 27 , wherein:
 (a) the compound of formula XXVI is reacted with carbon dioxide by addition of a solvent mixture containing the compound of formula XXVI to solid carbon dioxide; and/or   (b) the compound of formula XXVII is prepared by a process comprising the steps of
 (i) reaction of a compound of formula XXVIII, 
   
       
         
           
           
               
               
           
         
         
           wherein R s1  to R s3  are as defined in  claim 27 , with an aryl or C 1-6  alkyl lithium reagent, followed by reaction of the resulting alkynyl lithium intermediate with a compound of formula XXIX, 
         
       
       
         
           
           
               
               
           
         
         
           wherein R 2  and R 3  independently represent H or C 1-3  alkyl, or R 2  and R 3  together combine to form C 2-3  alkylene, at sub-ambient temperature, and 
         
         (ii) reaction of the resulting compound of formula XXX, 
       
       
         
           
           
               
               
           
         
         
           wherein R s1  to R s3  are as defined in  claim 27  and R 2  and R 3  independently represent H or C 1-3  alkyl, or R 2  and R 3  together combine to form C 2-3  alkylene, with a chlorinating, brominating or iodinating agent. 
         
       
     
     
         31 . A process for the preparation of a compound of formula XXXI, 
       
         
           
           
               
               
           
         
       
       wherein R 2  and R 3  independently represent H or C 1-3  alkyl, or R 2  and R 3  together combine to form C 2-3  alkylene, said process comprising:
 (i) a process as defined in  claim 27  for the preparation of a compound of formula XXV; followed by 
 (ii) removal of the —Si(R s1 )(R s2 )(R s3 ) protecting group. 
 
     
     
         32 . A process for the preparation of a compound of formula I, as defined in  claim 1 , said process comprising:
 (a) a process for the preparation of a compound of formula XXV,   
       
         
           
           
               
               
           
         
         wherein R s1  to R s3  independently represent C 1-4  alkyl and R 2  and R 3  are as defined in  claim 1 , said process comprising the steps of:
 (i) reaction of a compound of formula XXVI 
 
       
       
         
           
           
               
               
           
         
         
           wherein R s1  to R s3  are as defined above and R 2  and R 3  are as defined in  claim 1 , and Hal represents a halogen selected from the group consisting of Cl, Br and I, with carbon dioxide; and 
           (ii) acidification of the resulting carboxylic acid salt; or 
         
         (b) a process for the preparation of a compound of formula XXXI, 
       
       
         
           
           
               
               
           
         
       
       wherein R 2  and R 3  independently represent H or C 1-3  alkyl, or R 2  and R 3  together combine to form C 2-3  alkylene, said process comprising:
 (i) a process for the preparation of a compound of formula XXV as in (a) above; followed by 
 (ii) removal of the —Si(R s1 )(R s2 )(R s3 ) protecting group. 
 
     
     
         33 . A process according to  claim 27 , wherein:
 R s1  to R s3  all represent methyl; and/or   R 2  and R 3  both represent methyl.