1 H NMR ( CDCl 3 ) δ 8 . 61 ( 1 H , br dd , J = 4 . 9 , 1 . 8 Hz ) , 7 . 50 ( 1 H , br dd , J = 7 . 9 , 1 . 8 Hz ) , 7 . 45 ( 1 H , d , J = 1 . 8 Hz ) , 7 . 36 ( 1 H , d , J = 7 . 9 Hz ) , 7 . 27 - 7 . 22 ( 2 H , m ) , 7 . 20 ( 1 H , br ) , 4 . 64 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 4 . 58 ( 1 H , dd , J = 14 . 7 , 6 . 1 Hz ) , 3 . 82 ( 1 H , br ) , 3 . 72 ( 2 H , t , J = 5 . 5 Hz ) , 3 . 47 ( 1 H , s ) , 3 . 24 ( 1 H , d , J = 13 . 5 Hz ) , 3 . 17 ( 1 H , d , J = 13 . 5 Hz ) , 2 . 81 - 2 . 62 ( 3 H , m ) , 2 . 44 ( 1 H , m ) , 2 . 30 ( 1 H , m ) , 2 . 17 ( 1 H , m ) .