1 H NMR ( CDCl 3 ) δ 8 . 60 ( 1 H , br d , J = 4 . 9 Hz ) , 7 . 48 ( 1 H , br d , J = 7 . 9 Hz ) , 7 . 36 ( 1 H , m ) , 7 . 26 - 7 . 23 ( 1 H , br ) , 7 . 24 ( 1 H , dd , J = 7 . 9 , 4 . 9 Hz ) , 6 . 91 - 6 . 84 ( 2 H , m ) , 4 . 75 ( 1 H , m ) , 4 . 62 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 4 . 53 ( 1 H , dd , J = 14 . 7 , 5 . 5 Hz ) , 4 . 49 ( 1 H , br s ) , 2 . 61 - 2 . 27 ( 3 H , m ) , 2 . 02 ( 1 H , m ) .