abstract |
The invention provides novel compounds having the general formula: n n n n n n n n n n n n and tautomers and pharmaceutically acceptable salts thereof, wherein A 1 , A 2 , A 3 , A 4 , R 1 , R 4 , R 5 , R 6 , R 7 and R 8 are as defined herein, compositions including the compounds and methods of using the compounds. |