1 H NMR ( CDCl 3 ) δ 8 . 57 ( 1 H , ddd , J = 4 . 9 , 1 . 8 , 1 . 2 Hz ) , 7 . 52 ( 1 H , br d , J = 5 . 5 Hz ) , 7 . 43 - 7 . 41 ( 2 H , m ) , 7 . 33 ( 1 H , d , J = 1 . 8 Hz ) , 7 . 18 ( 1 H , dd , J = 7 . 9 , 4 . 9 Hz ) , 4 . 76 - 4 . 69 ( 3 H , m ) , 4 . 64 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 3 . 99 ( 1 H , br ) , 3 . 43 ( 1 H , br ) , 2 . 60 ( 1 H , m ) , 2 . 32 ( 1 H , m ) , 2 . 17 - 2 . 04 ( 2 H , m ) , 1 . 61 ( 3 H , s ) .