| abstract |
The present invention provides a compound of formula (I), or a tautomer or pharmaceutically acceptable salt thereof, wherein R 1 is selected from the following (II) and (III) N is an integer from 1 to 2 ; R 2 is hydrogen, amino, —NR 6 R 7 , optionally substituted alkyl of 1 to 12 carbon atoms, optionally Substituted aryl of 6, 10 or 14 carbon atoms, optionally substituted alkenyl of 2 to 12 carbon atoms, optionally substituted alkynyl of 2 to 12 carbon atoms, Selected from halogen and optionally substituted 5 to 10 membered heteroaryl rings, wherein the heteroaryl ring has 1 to 4 heteroatoms, which are independently N, O And S; R 3 , R 4 , R 5 , R 6 and R 7 , R 8 are as defined herein. |