Fused tricyclic compounds as inhibitors of tumor necrosis factor-alpha

A compound of formula (1a′):

• wherein
• R2 is hydrogen, alkyl, cycloalkyl, nitro, or NR11R12;
• R4 and R5 are each independently selected from:
• hydrogen, halogen, hydroxy, trifluoromethyl, alkyl, cycloalkyl, alkenyl and alkoxy;
• R7 is —(CH2)nC(O)R9;
• R9 is hydrogen, halogen, alkyl, cycloalkyl, trifluoromethyl or OR10, R10 is hydrogen, alkyl or cycloalkyl;
• R11 and R12 are each independently selected from:
• hydrogen, alkyl, cycloalkyl or
• —(CH2)nC(O)R9;
• R15 is H or alkyl;
• and
• n is 0, 1 or 2;
• where alkyl or cycloalkyl is unsubstituted or substituted by one or two of the same or different groups selected from:
• halogen, hydroxy, alkylcarboxy, amino, cycloalkyl, alkoxy, aryloxy, alkoxylcarbonyl, arylalkoxycarbonyl, aminocarbonyl, alkylamino, dialkylamino, cycloalkylamino, cycloalkylalkylamino, heterocyclylalkylamino, heteroaryl, heteroarylamino, heteroarylalkylamino, dialkylaminoalkylamino, aryl, aminoaryl, heteroaryl and heterocyclyl;
• in all its stereoisomeric and tautomeric forms and mixtures thereof in all ratios, and its pharmaceutically acceptable salts and solvates.