| abstract |
PROBLEM TO BE SOLVED: To provide a compound and a composition useful as a toll-like receptor 7/8 (TLR7 / 8) antagonist. SOLUTION: A compound of formula I or a pharmaceutically acceptable salt thereof. In formula I, ring A is pyridyl or pyrimidyl; ring B is pyridyl, pyrimidinyl, or pyrazinyl; X is C (R 4 ) 2 , O, NR 4 , S, S (R 4 ), or S (R 4 ) 2 ; R 4 is H, halogen, etc. [Selection diagram] None |