Pyrimidine and purine derivatives and their use in treating tumour cells

A pyrimidine derivative selected from

• A) 6-hetarylalkyloxy pyrimidine derivatives of formula II ##STR16## wherein R is a cyclic group having at least one 5- or 6-membered heterocyclic ring, optionally with a carbocyclic or heterocyclic ring fused thereto, the or each heterocyclic ring having at least one hetero atom selected from the group consisting of O, N and S, or a substituted derivative thereof having substitution of the heterocyclic ring(s) and/or carbocyclic ring(s) by one or more substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halo, haloalkyl, nitro, cyano, hydroxyalkyl, alkylenedioxy, SO.sub.n R"" where R"" is alkyl and n=0, 1 or 2, and a carboxyl or ester group of the formula --COOR.sup.c where R.sup.c is H or alkyl;
• R.sup.2 is a member selected from the group consisting of H, C.sub.1 -C.sub.5 alkyl, halogen and NH.sub.2 ;
• R.sup.4 and R.sup.5 which are the same or different are selected from the group consisting of H, NH.sub.2 and NO.sub.n', where n'=1 or 2;
• or
• R.sup.4 and R.sup.5 together form a ring structure III.sup.a ##STR17## wherein Y is H, HOCH.sub.2 CH.sub.2 OCH.sub.2 -, ribosyl, deoxyribosyl, arabinosyl, or ##STR18## wherein X is O or S, R" and R'" are alkyl or substituted derivatives thereof having substitution by one or more substituents selected from the group consisting of hydroxy, halo, alkoxy, amino, alkylamino, amido and ureido,
• R.sup.3 is H or OH;
• or
• R.sup.4 and R.sup.5 together with the pyrimidine ring form a 5- or 6- membered ring structure containing one or more hetero atoms other than that of formula III.sup.a above,
• and pharmaceutically acceptable salts thereof, provided that if R.sup.4 and R.sup.5 form a ring structure IX ##STR19## wherein Y' is H, ribosyl, deoxyribosyl, or ##STR20## wherein X is O or S, R" and R'" are alkyl, or substituted derivatives thereof, R.sup.2 is not NH.sub.2 ;
• and
• B) 6-arylalkyloxy pyrimidine derivatives selected from those of formulae III.sup.b, III.sup.c, IV.sup.b, V.sup.b, VI.sup.b, VI.sup.b and VII.sup.b as defined below:
• ##STR21## wherein R.sup.10 is phenyl or a substituted derivative thereof having substitution by one or more substituents selected from the group consisting of alkyl, alkenyl, alkynyl, halo, haloalkyl, nitro, cyano, hydroxyalkyl, alkylenedioxy and SO.sub.n R"" where R"" and n are as defined for formula II or a carboxyl or ester group of the formula --COOR.sup.c wherein R.sup.c is as defined for formula II;
• R.sup.11 is C.sub.1 -C.sub.5 alkyl;
• Y is as defined above;
• ##STR22## wherein R.sup.10 is as defined above;
• R.sup.2 is as defined for formula II;
• R.sup.3 is H or OH;
• ##STR23## wherein R.sup.10 is as defined above;
• Y is as defined for formula III.sup.a ;
• X is CH or N;
• provided that if X is N and Y is H, then
• R.sup.10 is not phenyl;
• ##STR24## wherein R.sup.10 is as defined above;
• X is CH or N;
• A is CH or N;
• ##STR25## wherein R.sup.10 is as defined above;
• Z is O or S or CH.dbd.CH;
• ##STR26## wherein R.sup.10 is as defined above;
• U is CH or N;
• V is CH or N;
• W is CH or N;
• ##STR27## wherein R.sup.10 is as defined above;
• T is H, NH.sub.2 or NO.sub.n where n=1 or 2;
• Q is H, NH.sub.2 or NO.sub.n where n=1 or 2;
• provided that:
• if Q is NH.sub.2 and T is NO or NO.sub.2, or
• if Q is H and T is NO.sub.2, or
• if Q and T are both NH.sub.2, or
• if Q is NH.sub.2, and T is H, then
• R.sup.10 is not phenyl.