Tetracyclic kinase inhibitors

A compound of formula I:

• wherein
• X, Y and Z are independently absent, CR4R4′, NR5, S, SO, SO2 or O;
• or X and Y together are CR4═CR4;
• or Y and Z together are CR4═CR4;
• wherein at least one of X, Y and Z is NR5, S, SO, SO2 or O;
• Ra and Rb are independently H or a protecting group;
• R1 is H, hydroxyl, halogen, amino, or is alkyl, acyl, alkoxy or alkylthio optionally substituted with hydroxyl, halogen, oxo, thione, amino, carboxyl and alkoxy;
• R2 is H, halogen, hydroxyl, mercapto, amino, alkyl, a carbocycle or a heterocycle, wherein said alkyl, carbocycle and heterocycle are optionally substituted with halogen, hydroxyl, mercapto, amino, carboxyl, alkyl, a carbocycle or a heterocycle and wherein one or more CH2 groups of an alkyl group is optionally replaced with —O—, —S—, —S(O)—, S(O)2, —N(R5)—, —C(O)—, —C(S)—, —C(O)—NR5—, —NR5—C(O)—, —SO2—NR5—, —NR5—SO2—, —NR5—C(O)—NR5—, —C(O)—O— or —O—C(O)—;
• R3 is halogen, hydroxyl, mercapto, amino, alkyl, a carbocycle or a heterocycle, wherein said alkyl, carbocycle and heterocycle are optionally substituted with halogen, hydroxyl, mercapto, amino, carboxyl, alkyl, a carbocycle or a heterocycle and wherein one or more CH2 groups of an alkyl group is optionally replaced with —O—, —S—, —S(O)—, S(O)2, —N(R5)—, —C(O)—, —C(S)—, —C(O)—NR5—, —NR5—C(O)—, —SO2—NR5—, —NR5—SO2—, —NR5—C(O)—NR5—, —C(O)—O— or —O—C(O)—;
• R4 and R4′ are independently H, hydroxyl, halogen, amino, alkyl, a carbocycle or a heterocycle, or R4 and R4′ together form oxo, thione, a carbocycle or heterocycle, wherein said alkyl, carbocycles and heterocycles are optionally substituted with halogen, hydroxyl, carboxyl, amino, alkyl, a carbocycle or a heterocycle and wherein one or more CH2 groups of an alkyl group is optionally replaced with —O—, —S—, —S(O)—, S(O)2, —N(R5)—, —C(O)—, —C(O)—NR5—, —NR5—C(O)—, —SO2—NR5—, —NR5—SO2—, —NR5—C(O)—NR5—, —C(O)—O— or —O—C(O)—;
• R5 is H, alkyl, a carbocycle or a heterocycle wherein one or more CH2 or CH groups of said alkyl is optionally replaced with —O—, —S—, —S(O)—, S(O)2, —NH—, or —C(O)—;
• and said alkyl, carbocycle and heterocycle is optionally substituted with hydroxyl, alkoxy, acyl, halogen, mercapto, oxo, carboxyl, acyl, halo-substituted alkyl, amino, cyano nitro, amidino, guanidino an optionally substituted carbocycle or an optionally substituted heterocycle;
• n is 0 to 3;
• and salts and solvates thereof.