Claims for Patent: 6,391,874

Summary for Patent: 6,391,874

Title:	Fused heterocyclic compounds as protein tyrosine kinase inhibitors
Abstract:	Substituted heteroaromatic compounds of formula (I) and in particular substituted quinolines and quinazolines, are protein tyrosine kinase inhibitors. The compounds are described as are methods for their preparation, pharmaceutical compositions including such compounds and their use in medicine, for example in the treatment of cancer and psoriasis, or a salt or solvate thereof; wherein X is N or CH; Y is a group W(CH.sub.2), (CH.sub.2)W, or W, in which W is O, S(O).sub.m wherein m is 0, 1 or 2, or NR.sup.a wherein R.sup.a is hydrogen or a C.sub.1-8 alkyl group; R.sup.1 represents a phenyl group or a 5- or 6-membered heterocyclic ring containing 1 to 4 heteroatoms selected from N, O or S(O).sub.m, wherein m is as defined above, with the provisos that the ring does not contain two adjacent O or S(O).sub.m atoms and that where the ring contains only N as heteroatom(s) the ring is C-linked to the quinazoline or quinoline ring, R.sup.1 being optionally substituted by one or more R.sup.3 ;groups; P=0 to 3; U, R.sup.2, R.sup.3 are as defined in the application. ##STR1##
Inventor(s):	Cockerill; George Stuart (Herts, GB), Carter; Malcolm Clive (Herts, GB), Guntrip; Stephen Barry (Herts, GB), Smith; Kathryn Jane (Herts, GB)
Assignee:	SmithKline Beecham Corporation (Philadelphia, PA)
Application Number:	09/214,267
Patent Claims:	1. A compound of formula (I): ##STR20## or a salt or solvate thereof; wherein X is N or CH; Y is a group W(CH.sub.2), (CH.sub.2)W, or W, in which W is O, S(O).sub.m wherein m is 0, 1 or 2, or NR.sup.a wherein R.sup.a is hydrogen or a C.sub.1-8 alkyl group; R.sup.1 represents a 5- or 6-membered heterocyclic ring containing 1 to 4 heteroatoms selected from N, O or S(O).sub.m, wherein m is as defined above, with the provisos that the ring does not have two adjacent O or S(O).sub.m atoms and that where the ring has only N as heteroatom(s) the ring is C-linked to the quinazoline or quinoline ring, R.sup.1 is optionally substituted by one or more R.sup.3 groups; each R.sup.3 is independently selected from the group consisting of amino, hydrogen, halogen, hydroxy, nitro, carboxy, formyl, cyano, trifluoromethyl, trifluoromethoxy, carbamoyl, ureido, guanidino, C.sub.1-8 alkyl, C.sub.1-8 alkoxy, C.sub.3-8 cycloalkoxyl, C.sub.4-8 alkylcycloalkoxy, C.sub.1-8 alkylcarbonyl, C.sub.1-8 alkoxycarbonyl, N-C.sub.1-4 alkylcarbamoyl, N,N-di-(C.sub.1-4 alkyl)carbamoyl, hydroxyamino, C.sub.1-4 alkoxyamino, C.sub.2-4 alkanoyloxyamino, C.sub.1-4 alkylamino, di(C.sub.1-4 alkyl)amino, di-(C.sub.1-4 alkyl)amino-C.sub.1-4 alkylene-(C.sub.1-4 alkyl)amino, C.sub.1-4 alkylamino-C.sub.1-4 alkylene-(C.sub.1-4 alkyl)amino, hydroxy-C.sub.1-4 alkylene-(C.sub.1-4 alkyl)amino, phenyl, phenoxy, 4-pyridon-1-yl, pyrrolidin-1-yl, imidazol-1-yl, piperidino, morpholino, thiomorpholino, thiomorpholino-1-oxide, thiomorpholino-1,1-dioxide, piperazin-1-yl, 4-C.sub.1-4 alkylpiperazin-1-yl, dioxolanyl, C.sub.1-8 alkylthio, arylthio, C.sub.1-4 alkylsulphinyl, C.sub.1-4 alkylsulphonyl, arylsulphonyl, arylsulphinyl, halogeno-C.sub.1-4 alkyl, hydroxy-C.sub.1-4 alkyl, C.sub.2-4 alkanoyloxy-C.sub.1-4 alkyl, C.sub.1-4 alkoxy-C.sub.1-4 alkyl, carboxy-C.sub.1-4 alkyl, formyl-C.sub.1-4 alkyl, C.sub.1-4 alkoxycarbonyl-C.sub.1-4 -alkyl, carbamoyl-C.sub.1-4 alkyl, N-C.sub.1-4 alkylcarbamoyl-C.sub.1-4 alkyl, N,N-di-(C.sub.1-4 alkyl)carbamoyl-C.sub.1-4 alkyl, amino-C.sub.1-4 alkyl, C.sub.1-4 alkylamino-C.sub.1-4 alkyl, di-(C.sub.1-4 alkyl)amino-C.sub.1-4 alkyl, phenyl-C.sub.1-4 alkyl, 4-pyridon-1-yl-C.sub.1-4 alkyl, pyrrolidin-1-yl-C.sub.1-4 alkyl, imidazol-1-yl-C.sub.1-4 alkyl, piperidino-C.sub.1-4 alkyl, morpholino-C.sub.1-4 alkyl, thiomorpholino-C.sub.1-4 alkyl, thiomorpholino-1-oxide-C.sub.1-4 alkyl, thiomorpholino-1,1-dioxide-C.sub.1-4 alkyl, piperazin-1-yl-C.sub.1-4 alkyl, 4-C.sub.1-4 alkylpiperazin-1-yl-C.sub.1-4 alkyl, hydroxy-C.sub.2-4 alkoxy-C.sub.1-4 alkyl, C.sub.1-4 alkoxy-C.sub.2-4 alkoxy-C.sub.1-4 alkyl, hydroxy-C.sub.2-4 alkylamino-C.sub.1-4 alkyl, C.sub.1-4 alkoxy-C.sub.2-4 alkylamino-C.sub.1-4 alkyl, C.sub.1-4 alkylthio-C.sub.1-4 alkyl, C.sub.1-4 alkylsulphinyl-C.sub.1-4 alkyl, C.sub.1-4 alkylsulphonyl-C.sub.1-4 alkyl, hydroxy-C.sub.2-4 alkylthio-C.sub.1-4 alkyl, C.sub.1-4 alkoxy-C.sub.2-4 alkylthio-C.sub.1-4 alkyl, phenoxy-C.sub.1-4 alkyl, anilino-C.sub.1-4 alkyl, phenylthio-C.sub.1-4 alkyl, cyano-C.sub.1-4 alkyl, halogeno-C.sub.2-4 alkoxy, hydroxy-C.sub.2-4 alkoxy, C.sub.2-4 alkanoyloxy-C.sub.2-4 alkoxy, C.sub.1-4 alkoxy-C.sub.2-4 alkoxy, carboxy-C.sub.1-4 alkoxy, formyl-C.sub.1-4 alkoxy, C.sub.1-4 alkoxycarbonyl-C.sub.1-4 alkoxy, carbamoyl-C.sub.1-4 alkoxy, N-C.sub.1-4 alkylcarbamoyl-C.sub.1-4 alkoxy, N,N-di-(C.sub.1-4 alkyl)carbamoyl-C.sub.1-4 alkoxy, amino-C.sub.2-4 alkoxy, C.sub.1-4 alkylamino-C.sub.2-4 alkoxy, di-(C.sub.1-4 alkyl)amino-C.sub.2-4 alkoxy, di-(C.sub.1-4 alkyl-C.sub.2-4 alkoxy)amino-C.sub.2-4 alkoxy, C.sub.2-4 alkanoyloxy, hydroxy-C.sub.2-4 alkanoyloxy, C.sub.1-4 alkoxy-C.sub.2-4 alkanoyloxy, phenyl-C.sub.1-4 alkoxy, phenoxy-C.sub.2-4 alkoxy, anilino-C.sub.2-4 alkoxy, phenylthio-C.sub.2-4 alkoxy, 4-pyridon-1-yl-C.sub.2-4 alkoxy, piperidino-C.sub.2-4 alkoxy, morpholino-C.sub.2-4 alkoxy, thiomorpholino-C.sub.2-4 alkoxy, thiomorpholino-1-oxide-C.sub.2-4 alkoxy, thiomorpholino-1,1-dioxide-C.sub.2-4 alkoxy, piperazin-1-yl-C.sub.2-4 alkoxy, 4-C.sub.1-4 alkylpiperazin-1-yl-C.sub.2-4 alkoxy, pyrrolidin-1-yl-C.sub.2-4 alkoxy, imidazol-1-yl-C.sub.2-4 alkoxy, halogeno-C.sub.2-4 alkylamino, hydroxy-C.sub.2-4 alkylamino, C.sub.2-4 alkanoyloxy-C.sub.2-4 alkylamino, C.sub.1-4 alkoxy-C.sub.2-4 alkylamino, carboxy-C.sub.1-4 alkylamino, C.sub.1-4 alkoxycarbonyl-C.sub.1-4 alkylamino, carbamoyl-C.sub.1-4 alkylamino, N-C.sub.1-4 alkylcarbamoyl-C.sub.1-4 alkylamino, N,N-di-(C.sub.1-4 alkyl)carbamoyl-C.sub.1-4 alkylamino, amino-C.sub.2-4 alkylamino, C.sub.1-4 alkylamino-C.sub.2-4 alkylamino, di-(C.sub.1-4 alkyl)amino-C.sub.2-4 alkylamino, phenyl-C.sub.1-4 alkylamino, phenoxy-C.sub.2-4 alkylamino, anilino-C.sub.2-4 alkylamino, 4-pyridon-1-yl-C.sub.2-4 alkylamino, pyrrolidin-1-yl-C.sub.2-4 alkylamino, imidazol-1-yl-C.sub.2-4 alkylamino, piperidino-C.sub.2-4 alkylamino, morpholino-C.sub.2-4 alkylamino, thiomorpholino-C.sub.2-4 alkylamino, thiomorpholino-1-oxide-C.sub.2-4 alkylamino, thiomorpholino-1,1-dioxide-C.sub.2-4 alkylamino, piperazin-1-yl-C.sub.2-4 alkylamino, 4-(C.sub.1-4 alkyl)piperazin-1-yl-C.sub.2-4 alkylamino, phenylthio-C.sub.2-4 alkylamino, C.sub.2-4 alkanoylamino, C.sub.1-4 alkoxycarbonylamino, C.sub.1-4 alkylsulphonylamino, C.sub.1-4 alkylsulphinylamino, benzamido, benzenesulphonamido, 3-phenylureido, 2-oxopyrrolidin-1-yl, 2,5-dioxopyrrolidin-1-yl, halogeno-C.sub.2-4 alkanoylamino, hydroxy-C.sub.2-4 alkanoylamino, hydroxy-C.sub.2-4 alkanoyl-(C.sub.1-4 alkyl)-amino, C.sub.1-4 alkoxy-C.sub.2-4 alkanoylamino, carboxy-C.sub.2-4 alkanoylamino, C.sub.1-4 alkoxycarbonyl-C.sub.2-4 alkanoylamino, carbamoyl-C.sub.2-4 alkanoylamino, N-C.sub.1-4 alkylcarbamoyl-C.sub.2-4 alkanoylamino, N,N-di-(C.sub.1-4 alkyl)carbamoyl-C.sub.2-4 alkanoylamino, amino-C.sub.2-4 alkanoylamino, C.sub.1-4 alkylamino-C.sub.2-4 alkanoylamino or di-(C.sub.1-4 alkyl)amino-C.sub.2-4 alkanoylamino; and wherein said benzamido or benzenesulphonamido substitutent or any anilino, phenoxy or phenyl group on a R.sup.3 substituent may optionally have one or two halogeno, C.sub.1-4 alkyl or C.sub.1-4 alkoxy substituents; and wherein any substituent having a heterocyclic ring may optionally have one or two halogeno, C.sub.1-4 alkyl or C.sub.1-4 alkoxy substituents on said ring; and wherein any substituent having a heterocyclic ring may optionally have one or two oxo or thioxo substituents on said ring; or R.sup.3 represents a group selected from M.sup.1 --M.sup.2 --M.sup.3 --M.sup.4, M.sup.1 --M.sup.5 or M.sup.1 --M.sup.2 --M.sup.3' --M.sup.6 wherein M.sup.1 represents a C.sub.1-4 alkyl group, wherein optionally a CH.sub.2 group is replaced by a CO group; M.sup.2 represents NR.sup.12 or CR.sup.12 R.sup.13, in which R.sup.12 and R.sup.13 each independently represent H or C.sub.1-4 alkyl; M.sup.3 represents a C.sub.1-4 alkyl group; M.sup.3' represents a C.sub.1-4 alkyl group or is absent; M.sup.4 represents CN, NR.sup.12 S(O).sub.m R.sup.13, S(O).sub.m NR.sup.14 R.sup.15, CONR.sup.14 R.sup.15, S(O).sub.m R.sup.13 or CO.sub.2 R.sup.13, in which R.sup.12, R.sup.13 and m are as above defined and R.sup.14 and R.sup.15 each independently represent H or C.sub.1-4 alkyl, or R.sup.14 and R.sup.15 together with the nitrogen atom to which they are attached form a 5- or 6-membered ring optionally containing 1 or 2 additional heteroatoms selected from N, O or S(O).sub.m in which ring any nitrogen atom present may optionally be substituted with a C.sub.1-4 alkyl group, and which ring may optionally contained one or two oxo or thioxo substituents; M.sup.5 represents the group NR.sup.14 R.sup.15, wherein R.sup.14 and R.sup.15 are as defined above, or M.sup.5 represents the group ##STR21## in which t represents 2 to 4 and R.sup.16 represents OH, OC.sub.1-4 alkyl or NR.sup.14 R.sup.15 ; and M.sup.6 represents a C.sub.3-6 cycloalkyl group, the group NR.sup.14 R.sup.15, wherein R.sup.14 and R.sup.15 are as defined above, or a 5- or 6-membered heterocyclic ring system containing 1 to 4 heteroatoms selected from N, O or S; and p is 0 to 3; or when p is 2 or 3, two adjacent R.sup.3 groups together form an optionally substituted methylenedioxy or ethylenedioxy group; R.sup.2 is selected from the group consisting of hydrogen, halogen, trifluoromethyl, C.sub.1-4 alkyl and C.sub.1-4 alkoxy; U represents phenyl or a 5 to 10-membered mono or bicyclic ring system in which one or more of the carbon atoms is optionally replaced by a heteroatom independently selected from N, O and S(O).sub.m, wherein m is 0, 1 or 2, and wherein U is substituted by at least one independently selected R.sup.6 group and U is optionally substituted by at least one independently selected R.sup.4 group; each R.sup.4 is independently hydrogen, hydroxy, halogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, C.sub.1-4 alkylamino, di-[C.sub.1-4 alkyl]amino, C.sub.1-4 alkylthio, C.sub.1-4 alkylsulphinyl, C.sub.1-4 alkylsulphonyl, C.sub.1-4 alkylcarbonyl, C.sub.1-4 alkylcarbamoyl, di-[C.sub.1-4 alkyl]carbamoyl, carbamyl, C.sub.1-4 alkoxycarbonyl, cyano, nitro or trifluoromethyl; each R.sup.6 is independently a group ZR.sup.7 wherein Z is joined to R.sup.7 through a (CH.sub.2)p group in which p is 0, 1 or 2 and Z represents a group V(CH.sub.2), V(CF.sub.2), (CH.sub.2)V, (CF.sub.2)V, V(CRR'), V(CHR) or V where R and R' are each C.sub.1-4 alkyl and in which V is a hydrocarbyl group containing 0, 1 or 2 carbon atoms, carbonyl, dicarbonyl, CH(OH), CH(CN), sulphonamide, amide, O, S(O).sub.m or NR.sup.b where R.sup.b is hydrogen or R.sup.b is C.sub.1-4 alkyl; and R.sup.7 is an optionally substituted C.sub.3-6 cycloalkyl; or an optionally substituted 5, 6, 7, 8, 9 or 10-membered carbocyclic or heterocyclic moiety; or R.sup.6 is a group ZR.sup.7 in which Z is NR.sup.b, and NR.sup.b and R.sup.7 together form an optionally substituted 5, 6, 7, 8, 9 or 10-membered carbocyclic or heterocyclic moiety. 2. A compound as claimed in claim 1 wherein R.sup.3 is as defined in claim 1 with the exception of wherein any substituent containing a heterocyclic ring has one or two oxo or thioxo substituents on said ring, and with the exception of C.sub.1-4 alkylsulphinyl-C.sub.1-4 alkyl or C.sub.1-4 alkylsulphonyl-C.sub.1-4 alkyl; and wherein R.sup.14 and R.sup.15 are as defined in claim 1 with the exception of wherein R.sup.14 and R.sup.15 together with the nitrogen atom to which they are attached represent a 5- or 6-membered ring and said ring has one or two oxo or thioxo substituents; wherein R.sup.3 includes 4-pyridon-1-yl, 4-pyridon-1-yl-C.sub.1-4 alkyl, 4-pyridon-1-yl-C.sub.2-4 alkoxy, 4-pyridon-1-yl-C.sub.2-4 alkylamino, 2-oxopyrrolidin-1-yl or 2,5-dioxopyrrolidin-1-yl. 3. A compound as claimed in claim 1 wherein X is N. 4. A compound as claimed in claim 1 wherein Y is NR.sup.b, NR.sup.b (CH.sub.2), or (CH.sub.2)NR.sup.b. 5. A compound as claimed in claim 1 wherein R.sup.1 is a 5- or 6-membered heterocyclic ring as defined in claim 1, optionally substituted by one or more R.sup.1 groups selected from the group consisting of amino, hydrogen, halogen, hydroxy, hydroxy-C.sub.1-4 alkyl, formyl, carboxy, cyano, nitro, C.sub.1-8 alkyl, C.sub.1-8 alkoxy, C.sub.1-8 alkylthio, C.sub.1-8 alkylsulphinyl, C.sub.1-8 alkylsulphonyl, C.sub.1-4 alkylamino, C.sub.1-4 dialkylamino, dioxolanyl or hydroxy-C.sub.1-4 alkanoyl-(C.sub.1-4 alkyl)-amino. 6. A compound as claimed in claim 1 wherein R.sup.1 is a 5- or 6-membered heterocyclic ring substituted by one or more R.sup.3 groups selected from the group consisting of C.sub.1-4 alkyl, C.sub.1-4 alkylamino-C.sub.1-4 alkyl, di(C.sub.1-4 alkyl)amino-C.sub.1-4 alkyl, formyl, carboxy, C.sub.1-4 alkoxycarbonyl, dioxolanyl and trifluoromethyl. 7. A compound as claimed in claim 1 wherein R.sup.1 is a 5- or 6-membered heterocyclic ring substituted by one or more R.sup.3 groups selected from C.sub.1-4 alkylsulphinyl-C.sub.1-4 alkyl or C.sub.1-4 alkylsulphonyl-C.sub.1-4 alkyl. 8. A compound as claimed in claim 1 wherein R.sup.1 is a 5- or 6-membered heterocyclic ring substituted with an R.sup.3 group selected from M.sup.1 --M.sup.2 --M.sup.3 --M.sup.4, M.sup.1 --M.sup.5 or M.sup.1 --M.sup.2 --M.sup.3' --M.sup.6 as defined in claim 1 or claim 2; and p=0. 9. A compound as claimed in claim 1 wherein R.sup.1 is a 5- or 6-membered heterocyclic ring substituted with an R.sup.3 group selected from piperidonyl-methyl, pyrrolidinonyl-methyl or dioxoimidazolidinyl-methyl. 10. A compound as claimed in claim 1 wherein M.sup.1 represents CH.sub.2, CO, CH.sub.2 CH.sub.2 or CH.sub.2 CO; M.sup.2 represents NR.sup.12 in which R.sup.12 is as defined in claim 1; M.sup.3 represents CH.sub.2, CH.sub.2 CH.sub.2 or propyl; M.sup.3' represents CH.sub.2, ethyl, propyl, isopropyl or is absent; M.sup.4 represents SOR.sup.13, SO.sub.2 R.sup.13, NR.sup.12 SO.sub.2 R.sup.13, SO.sub.2 NR.sup.14 R.sup.15, CO.sub.2 R.sup.13 or CONR.sup.14 R.sup.15 in which R.sup.12 and R.sup.13 are defined in claim 1 and R.sup.14 and R.sup.15 each independently represent H or C.sub.1-4 alkyl; M.sup.5 represents a group NR.sup.14 R.sup.15 in which R.sup.14 and R.sup.15 together with the nitrogen atom to which they are attached represent a 6-membered ring optionally containing an additional heteroatom selected from N or O, in which ring any nitrogen atom present may optionally be substituted with a C.sub.1-4 alkyl group; or M.sup.5 represents a group ##STR22## in which t represents 2 or 3 and R.sup.16 represents OH, NH.sub.2, N(C.sub.1-4 alkyl).sub.2 or OC.sub.1-4 alkyl; or M.sup.5 represents a group NR.sup.14 R.sup.15 in which R.sup.14 and R.sup.15 each independently represent hydrogen or C.sub.1-4 alkyl, and M.sup.6 represents a group NR.sup.14 R.sup.15 in which R.sup.14 and R.sup.15 each independently represent C.sub.1-4 alkyl, or R.sup.14 and R.sup.15 together with the nitrogen atom to which they are attached represent a 5- or 6-membered ring optionally containing an additional heteroatom selected from N or O, in which ring any nitrogen atom present may optionally be substituted with a C.sub.1-4 alkyl group; or M.sup.6 represents a 5- or 6-membered heterocyclic ring system containing 1 or 2 heteroatoms selected from N or O. 11. A compound as claimed in claim 1 wherein M.sup.2 --M.sup.3 --M.sup.4 represents an .alpha.-amino carboxylic acid or a methyl ester or amide thereof; or M.sup.2 --M.sup.3 --M.sup.4 represents a .beta.- or .gamma.-amino sulphinic or sulphonic acid or a methyl ester thereof. 12. A compound as claimed in claim 1 wherein M.sup.2 --M.sup.3 --M.sup.4 represents a methylsulphonylethylamino, methylsulphinylethylamino, methylsulphonylethyl(methylamino), methylsulphinylethyl(methylamino), methylsulphonylpropylamino, methylsulphinylpropylamino, methylsulphonamidoethylamino, aminosulphonylethylamino, methylaminosulphonylethylamino, sarcosinamide, glycine, glycinamide, glycine methyl ester or acetylaminoethylamino group. 13. A compound as claimed in claim 1 wherein M.sup.1 --M.sup.5 represents a piperazinyl-methyl, methylpiperazinyl-methyl, piperidinyl-methyl, pyridylmethyl, prolinamidomethyl, N,N-dimethylprolinamido-methyl, isopropylacetamido or N-morpholinoacetamido group. 14. A compound as claimed in claim 1 wherein M.sup.1 --M.sup.5 represents a piperidonyl-methyl, pyrrolidinonyl-methyl or dioxoimidazolidinyl-methyl group. 15. A compound as claimed in claim 1 wherein M.sup.2 --M.sup.3' M.sup.6 represents a pyridylamino, cyclopropylamino, N-(piperidin-4-yl)-N-methylamino, N,N-dimethylaminoprop-2-ylamino, N-(2-dimethylaminoethyl)-N-ethylamino or tetrahydrofuranomethylamino group, preferably a pyridylamino group. 16. A compound as claimed in claim 1 wherein R.sup.1 is selected from the group consisting of furan, dihydrofuran, thiophene, imidazole, tetrazole, triazole, pyridine, pyrrole, pyrimidine, isoxazole or oxadiazole. 17. A compound as claimed in claim 1 wherein R.sup.1 is an oxadiazolidinone ring. 18. A compound as claimed in claim 16 wherein R.sup.1 is selected from the group consisting of furan, imidazole, oxadiazole and triazole. 19. A compound as claimed in claim 1 wherein R.sup.6 is benzyl, fluorobenzyl, difluorobenzyl, benzyloxy, fluorobenzyloxy, pyridylmethyl, phenyl, benzenesulphonyl, phenoxy or fluorophenoxy. 20. A compound as claimed in claim 1 wherein U represents an phenyl, indolyl, isoindolyl, indolinyl, isoindolinyl, 1H-indazolyl, 2,3-dihydro-1H-indazolyl, 1H-benzimidazolyl, 2,3-dihydro-1H-benzimidazolyl or 1H-benzotriazolyl group. 21. A compound as claimed in claim 20 wherein U represents a phenyl or 1H-indazolyl group. 22. A compound as claimed in claim 1 wherein the optional substituents for the carbocyclic or heterocyclic moiety and also for other optionally substituted groups are selected from the group consisting of hydroxy, halogen, trifluoromethyl, trifluoromethoxy, nitro, amino, cyano, C.sub.1-4 alkoxy, C.sub.1-4 alkylthio, C.sub.1-4 alkyl carbonyl, carboxylate and C.sub.1-4 alkoxy carboxyl. 23. A compound of formula (I) or a salt thereof as claimed in claim 1 wherein X represents N; Y represents NR.sup.a, wherein R.sup.a is hydrogen or C.sub.1-4 alkyl; R.sup.1 represents furan, thiophene, pyrrole, pyridine, pyrimidine, pyrazine, imidazole, oxazole, isoxazole, oxadiazole, tetrazole, triazole, dioxolane or a partially or fully hydrogenated derivative of any of these groups, optionally substituted by one or more R.sup.3 groups selected from halo, trifluoromethyl, C.sub.1-4 alkyl, carboxy, C.sub.1-4 -alkoxycarbonyl, formyl, hydroxy-C.sub.1-4 alkyl, 1,3-dioxolan-2-yl, amino, C.sub.1-4 alkylamino, di(C.sub.1-4 alkyl)amino, hydroxy-C.sub.1-4 alkanoyl-(C.sub.1-4 alkyl)-amino, C.sub.1-4 alkylamino-C.sub.1-4 alkyl or di(C.sub.1-4 alkyl)amino-C.sub.1-4 alkyl; p is 0; R.sup.2 represents hydrogen; R.sup.4 represents hydrogen, halo or methyl; U represents phenyl, indolyl, benzimidazolyl or indazolyl; and R.sup.6 represents phenyl, benzyl, .alpha.-methylbenzyl, fluorobenzyl, difluorobenzyl, pyridylmethyl, benzenesulphonyl, phenoxy, fluorophenoxy, benzyloxy or fluorobenzyloxy. 24. A compound of formula (I) or a salt thereof as claimed in claim 1 wherein X represents N; Y represents NR.sup.a, wherein R.sup.a is hydrogen or C.sub.1-4 alkyl; R.sup.1 represents furan, thiophene, pyrrole, pyridine, pyrimidine, pyrazine, imidazole, oxazole, isoxazole, oxadiazole, tetrazole, triazole, dioxolane or a partially or fully hydrogenated derivative of any of these groups, optionally substituted with an R.sup.3 group selected from methylsulphonylethylaminomethyl, methylsulphonylethylamino-carbonyl, methylsulphinylethylamino-methyl, methylsulphinylethylamino-carbonyl, methylsulphonylpropylamino-methyl, methylsulphinylpropylamino-methyl, methylsulphonylpropyamino-carbonyl, methylsulphinylpropylamino-carbonyl, methylsulphonylethyl-(methylamino)-methyl, methylsulphonylethyl-(methylamino)-carbonyl, methylsulphinylethyl-(methylamino)-methyl, methylsulphinylethyl-(methylamino)-carbonyl, methylsulphonylpropyl-(methylamino)-methyl, methylsulphinylpropyl-(methylamino)-methyl, methylsulphonylpropyl-(methylamino)-carbonyl, methylsulphinylpropyl-(methylamino)-carbonyl, methylsulphonamidoethylamino-methyl, methylsulphonamidopropylamino-methyl, aminosulphonylethylaminomethyl, methylaminosulphonylethylaminomethyl, sarcosinamidomethyl, glycinylmethyl, glycinamidomethyl, glycinylmethyl methyl ester acetylaminoethylaminomethyl, piperazinylmethyl, methylpiperazinylmethyl, piperidinylmethyl, pyridylmethyl, N-(prolinamido)methyl, (N,N-dimethyl-prolinamido)methyl, pyridylaminomethyl, cyclopropylaminomethyl, N-(piperidin-4-yl)-N-methylaminomethyl, N,N-dimethylaminoprop-2-ylaminomethyl, N-(2-dimethylaminoethyl)-N-ethylaminomethyl, isopropylacetamido, N-morpholinylacetamido or tetrahydrofuranomethylaminomethyl and optionally further substituted by one or more C.sub.1-4 alkyl groups; p is 0; R.sup.2 represents hydrogen; R.sup.4 represents hydrogen, halo or methyl; U represents phenyl, indolyl, benzimidazolyl or indazolyl; and R.sup.6 represents phenyl, benzyl, .alpha.-methylbenzyl, fluorobenzyl, difluorobenzyl, pyridylmethyl, benzenesulphonyl, phenoxy, fluorophenoxy, benzyloxy or fluorobenzyloxy. 25. A compound of formula (I) or a salt thereof as claimed in claim 23 wherein X represents N; Y represents NR.sup.a, wherein R.sup.a is hydrogen or C.sub.1-4 alkyl; R.sup.1 represents a furan, dihydrofuran, thiophene, pyridine, pyrrole, pyrimidine, isoxazole, triazole, tetrazole, imidazole or oxadiazole ring, substituted with an R.sup.3 group selected from C.sub.1-4 alkyl, C.sub.1-4 alkylamino-C.sub.1-4 alkyl, di(C.sub.1-4 alkyl)amino-C.sub.1-4 alkyl, formyl, carboxy, C.sub.1-4 alkoxycarbonyl, dioxolanyl, trifluoromethyl, methylsulphonylethylaminomethyl, methylsulphonylethylamino-carbonyl, methylsulphonylethyl(methylamino)-methyl, methylsulphonamidoethylamino-methyl, aminosulphonylethylamino-methyl, methylaminosulphonylethylamino-methyl, N,N-dimethylaminoprop-2-ylaminomethyl, N-(2-dimethylaminoethyl)-N-ethylaminomethyl, pyridylaminomethyl, tetrahydrofuranomethylaminomethyl, piperazinylmethyl, methylpiperazinylmethyl, piperidinylmethyl, pyridylmethyl, N-(prolinamido)methyl or (N,N-dimethyl-prolinamido)methyl; p is 0; R.sup.2 represents hydrogen; R.sup.4 represents hydrogen or halo; U represents phenyl or indazolyl; and R.sup.6 represents benzyl, fluorobenzyl, difluorobenzyl, pyridylmethyl, benzenesulphonyl, phenoxy, benzyloxy or fluorobenzyloxy. 26. A compound as claimed in claim 1 selected from the group consisting of: (4-Benzyloxy-phenyl)-(6-furan-2-yl-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(thiophen-2-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(pyridin-2-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(pyrimidin-2-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-(1,3-dioxolan-2-yl)-furan-2-yl-quinazolin-4-yl)- amine; (4-Benzyloxy-phenyl)-(6-(3-methyl-3H-imidazol-4-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(2,3-dihydrofuran-5-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(3-methyl-1,2,3-triazol-4-yl)-quinazolin-4-yl)-amin e; 5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-carbaldehyde; (4-Benzyloxy-phenyl)-(6-(5-(4-methylpiperazin-1-ylmethyl)-furan-2-yl)-quina zolin-4-yl)-amine; (S)-1-(5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-py rrolidine-2-carboxylic acid amide; N2-(5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-N1,N1 -dimethyl-propane-1,2-diamine; N-(5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-N-ethy l-N',N'-dimethyl-ethane-1,2-diamine; (4-Benzyloxy-phenyl)-(6-(5-(pyridin-3-ylaminomethyl)-furan-2-yl)quinazolin- 4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-(((tetrahydro-furan-2-ylmethyl)-amino)-methyl)-f uran-2-yl)-quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-(1,3)-dioxolan-2-yl-furan-2-yl)-quinazolin -4-yl)-amine; 5-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-furan-2-carbaldehyde; (S)-1-(5-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-furan-2-ylmeth yl)-pyrrolidine-2-carboxylic acid amide; (1-Benzyl-1H-indazol-5-yl)-(6-(5-((2-methanesulphonyl-ethylamino)-methyl)-f uran-2-yl)-quinazolin-4-yl)-amine; (4-Phenoxy-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)quinazolin-4-yl)-amine ; (1-(2-Fluorobenzyl)-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-qui nazolin-4-yl)-amine; (1-(3-Fluorobenzyl)-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-qui nazolin-4-yl)-amine; (1-Pyridin-2-ylmethyl)-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)- quinazolin-4-yl)-amine; (1-(2,3-Difluorobenzyl)-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl) quinazolin-4-yl)-amine; (3-Chloro-4-(2-fluoro-benzyloxy)-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl) -quinazolin-4-yl)-amine; (3-Chloro-4-(3-fluoro-benzyloxy)-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl) -quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-quinazolin-4-yl)-am ine; (4-(2-Fluoro-benzyloxy)-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-quinazol in-4-yl)-amine; (4-(3-Fluoro-benzyloxy)-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-quinazol inyl)-amine; (4-Benzenesulphonyl-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-quinazolin-4 -yl)-amine; (1-(3,5-Difluoro-benzyl)-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl )-quinazolin-4-yl)-amine (4-(4-Fluoro-benzyloxy)-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-quinazol in-4-yl)-amine; (4-(2-Fluoro-benzyloxy)-phenyl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol-2-yl) -quinazolin-4-yl)-amine; (4-(3-Fluorobenzyloxy)-phenyl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol-2-yl)- quinazolin-4-yl)-amine; (4-(4-Fluoro-benzyloxy)-phenyl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol-2-yl) -quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol-2-yl)-quin azolin-4-yl)-amine; (4-Pyridin-3-ylmethoxy)-phenyl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol-2-yl) -quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(3-methyl-3H-imidazol-4-yl)-quinazolin-4-yl)- amine; (1-Benzyl-1H-indazol-5-yl)-(6-(1-methyl-1H-imidazol-2-yl)quinazolin-4-yl)-a mine; (4-Benzyloxy-phenyl)-(6-(1H-tetrazol-5-yl)-quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)-quinazolin-4- yl0-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-triazol-2-yl)-quinazolin-4-yl )-amine; (S)-1-(2-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-3-methyl-3H-imidazol -4-ylmethyl)-pyrrolidine-2-carboxylic acid amide; (1-Benzyl-1H-indazol-5-yl)-(6-(5-methanesulphonylmethyl-1,3,4-oxadiazol-2-y l)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(1-methylpyridinium-2-yl)quinazolin-4-yl)-amine; chloride; (4-Benzyloxy-phenyl)-(6-(2,3-dimethyl-3H-imidazol-4-yl)-quinazolin-4-yl)-am ine; (4-Benzyloxy-phenyl)-(-6-(3-methylisoxazol-5-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-(((2-methanesulphonyl-ethyl)-methyl-amino)-methy l)-furan-2-yl)-quinazolin-4-yl)-amine; N-(2-((5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-am ino)-ethyl)-methanesulphonamide; 2-((5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-amino )-ethanesulphonic acid amide; 5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-carboxylic acid methyl ester; 5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-carboxylic acid; 5-[4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl]-furan-2-carboxylic acid (2-methanesulphonyl-ethyl)-amide; 2-((5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-amino )-ethanesulphonic acid methylamide; (1-Benzyl-1H-indazol-5-yl)-(6-(3-methyl-1,2,4-oxadiazol-5-yl)-quinazolin-4- yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-methyl-1,2,4-oxadiazol-3-yl)-quinazolin-4-yl)-am ine; (4-Benzyloxy-phenyl)-(6-(5-(2-dimethylamino-ethyl)-1,2,4-oxadiazol-3-yl)-qu inazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-(dimethylaminomethyl)-1,2,4-oxadiazol-3-yl)-quin azolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-(((2-methanesulphonyl-ethyl)-amino)-methyl )-1,2,4-oxadiazol-3-yl)-quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-methanesulphonylmethyl-1,2,4-oxadiazol-3-y l)-quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-methyl-1,2,4-oxadiazol-3-yl)-quinazolin-4- yl0-amine; (1-Benzyl-1H-indazol-5-yl)-6-(5-(pyridin-3-ylmethyl)-1,2,4-oxadiazol-3-yl)- quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(1-methylpyrrol-2-yl)-quinazolin-4-yl)-amine; 5-(4-(1-Benzyl-1H-indazol-5-yl)-quinazolin-6-yl)-1-methyl-pyrrole-2-carbald ehyde; 1-(3-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-1,2,4-oxadiazol-5- ylmethyl)-piperidin-4-one; 1-(3-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-1,2,4-oxadiazol-5- ylmethyl)-pyrrolidin-2-one; 1-(3-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-1,2,4-oxadiazol-5- ylmethyl)-imidazolidin-2,5-dione; 3-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-4H-1,2,4-oxadiazolidi n-3-one; (1-Benzyl-1H-indazol-5-yl)-(6-(5-((2-methanesuphonyl-ethyl-amino)-methyl)-1 -methyl-pyrrol-2-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(1-(3-N,N-dimethylaminopropyl)-imidazol-5-yl)-quina zolin-4-yl)-amine; (1-Benzyl-1H-indazolyl)-(6-(1-(3-N,N-dimethylaminopropyl)-imidazol-5-yl)-qu inazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(1-(3-N,N-dimethylaminopropyl)-imidazol-2-yl)-quina zolin-4-yl)-amine; (1-Benzyl-1H-indazolyl)-(6-(1-(3-N,N-dimethylaminopropyl)-imidazol-5-yl)-qu inazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol-2-yl)-quinazolin -4-yl)-amine; (1-(2-Fluoro-benzyl)-1H-indazol-5-yl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol -2-yl)-quinazolin-4-yl)-amine; (1-(3-Fluoro-benzyl)-1H-indazol-5-yl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol -2-yl)-quinazolin-4-yl)-amine; (1-(4-Fluoro-benzyl)-1H-indazol-5-yl)-(6-(5-trifluoromethyl-1,3,4-oxadiazol -2-yl)-quinazolin-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(7-(5-methyl-[1,3,4]oxadiazol-2-yl)-quinazolin-4 -yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(7-(3-methyl-3H-imidazol-4-yl)quinazolin-4-yl)-a mine; (1-Benzyl-1H-indazol-5-yl)-[7-(furan-2-yl)-quinazolin-4-yl]-amine; (1-Benzyl-1H-indazol-5-yl)-[7-(5-(1,3-dioxolan-2-yl)-furan-2-yl)quinazolin- 4-yl]amine; 5-[4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-7-yl]-furan-2-carbaldehyde; (1-Benzyl-1H-indazol-5-yl)-[7-{5-[(2-methanesulphonyl-ethylamino)-methyl]-f uran-2-1}-quinazolin-4-yl]-amine; (S)-1-{5-[4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-7-yl]-furan-2-yl-met hyl}-pyrrolidine-2-carboxylic acid amide; (4-Benzyloxy-phenyl)-(6-(3-methyl-[1,2]oxazol-4-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(4-(1,3-dioxolan-2-yl)-3-methyl-3H-imidazol-2-yl)-q uinazolin-4-yl)-amine; 2-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-3-methyl-3H-imidazol-4-carb aldehyde; and salts thereof. 27. A compound as claimed in claim 26 selected from the group consisting of: (4-Benzyloxy-phenyl)-(6-furan-2-yl-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(3-methyl-3H-imidazol-4-yl)-quinazolin-4-yl)-amine; (4-(4-Fluoro-benzyloxy)-phenyl)-(6-(5-methyl-1,3,4-oxadiazol-2-yl)quinazoli n-4-yl)-amine; (1-Benzyl-1H-indazol-5-yl)-(6-(5-methyl-1,3,4-triazol-2-yl)-quinazolin-4-yl )-amine; (4-Benzyloxy-phenyl)-(6-(5-methyl-1,2,4-oxadiazol-3-yl)-quinazolin-4-yl)-am ine; (4-Benzyloxy-phenyl)-(6-(5-(4-methylpiperazin-1-ylmethyl)-furan-2-yl)-quina zolin-4-yl)-amine; (S)-1-(5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-py rrolidine-2-carboxylic acid amide; (S)-1-(5-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-furan-2-ylmeth yl)-pyrrolidine-2-carboxylic acid amide; (1-Benzyl-1H-indazol-5-yl)-(6-(5-((2-methanesulphonyl-ethylamino)-methyl)-f uran-2-yl)-quinazolin-4-yl)-amine; (4-Benzyloxy-phenyl)-(6-(5-(((2-methanesulphonyl-ethyl)-methyl-amino)-methy l)-furan-2-yl)-quinazolin-4-yl)-amine; N-(2-((5-(4-(4-Benzyloxy-phenylamino)-quinazolin-6-yl)-furan-2-ylmethyl)-am ino)-ethyl)-methanesulphonamide; 1-(3-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-1,2,4-oxadiazol-5- ylmethyl)-piperidin-4-one; 1-(3-(4-(1-Benzyl-1H-indazol-5-ylamino)-quinazolin-6-yl)-1,2,4-oxadiazol-5- ylmethyl)-pyrrolidin-2-one and salts thereof. 28. A pharmaceutical formulation comprising at least one compound of claim 1 or a pharmaceutically acceptable salt thereof, together with one or more pharmaceutically acceptable carriers, diluents or excipients. 29. A pharmaceutical formulation as claimed in claim 28 in unit dosage form and containing from 70 to 700 mg of said compound. 30. A method of treatment of a human or animal subject suffering from a disorder mediated by aberrant protein tyrosine kinase activity which method comprises administering to the human or animal subject an effective amount of a compound of claim 1 or a pharmaceutically acceptable salt thereof. 31. A method of treating a disorder mediated by aberrant protein tyrosine kinase activity in a human or animal subject, wherein at least one kinase selected from the group consisting of c-erb-B2, EGFr, and c-erb-B4 exhibits aberrant activity, comprising administering to the human or animal an effective amount of a compound of formula I or a salt thereof. 32. A method of treating a disorder mediated by aberrant protein tyrosine kinase activity in a human or animal subject, wherein at least two kinases selected from the group consisting of c-erb-B2, EGFr, and c-erb-B4 exhibits aberrant activity, comprising administering to the human or animal an effective amount of a compound of formula I.