1 H NMR ( CDCl 3 ) δ 8 . 61 ( 1 H , dt , J = 4 . 7 , 1 . 6 Hz ) , 7 . 51 ( 1 H , dt , J = 8 . 0 , 1 . 5 Hz ) , 7 . 44 ( 1 H , s ) , 7 . 35 ( 1 H , d , J = 8 . 19 Hz ) , 7 . 16 - 7 . 29 ( 3 H , m ) , 4 . 53 - 4 . 66 ( 2 H , m ) , 3 . 46 - 3 . 64 ( 2 H , m ) , 3 . 03 ( 1 H , d , J = 14 . 1 Hz ) , 2 . 85 ( 1 H , d , J = 14 . 1 Hz ) , 2 . 49 - 2 . 75 ( 3 H , m ) , 2 . 13 - 2 . 40 ( 6 H , m ) 1 . 99 - 2 . 10 ( 1 H , m ) .