| abstract |
There is provided compounds of formula (I), wherein A 1 , A 2 , A 3 , A 4 , n, the dotted lines, B 1 , B 1a , B 2 , B 2a , B 3 , B 3a , B 4 , B 4a , R 2 and R 3 have meanings given in the description, and pharmaceutically-acceptable esters, amides, solvates or salts thereof, which compounds are useful in the treatment of diseases in which inhibition of a protein kinase (e.g. a PI3-K and/or mTOR) is desired and/or required, and particularly in the treatment of cancer or a proliferative disease. |