1 H NMR ( CDCl 3 ) δ 8 . 43 ( 1 H , s ) , 7 . 56 ( 1 H , s ) , 4 . 79 ( 1 H , m ) , 3 . 82 ( 3 H , s ) , 2 . 68 ( 1 H , m ) , 2 . 37 ( 1 H , m ) , 2 . 35 ( 3 H , s ) , 2 . 24 - 2 . 11 ( 2 H , m ) , 1 . 86 ( 1 H , br ) .