1 H NMR ( CDCl 3 ) δ 8 . 72 ( 1 H , d , J = 1 . 4 Hz ) , 7 . 73 ( 1 H , d , J = 1 . 4 Hz ) , 3 . 86 ( 3 H , s ) , 3 . 03 - 2 . 99 ( 2 H , m ) , 2 . 82 ( 1 H , m ) , 2 . 61 ( 1 H , m ) , 2 . 48 ( 3 H , s ) .