1 H NMR ( CDCl 3 ) δ 8 . 58 ( 1 H , m ) , 7 . 42 ( 1 H , d , J = 1 . 8 Hz ) , 7 . 39 ( 1 H , d , J = 7 . 9 Hz ) , 7 . 25 - 7 . 20 ( 2 H , m ) , 7 . 19 ( 1 H , d , J = 7 . 9 Hz ) , 6 . 79 ( 1 H , br ) , 4 . 80 ( 1 H , ddd , J = 6 . 4 , 5 . 2 , 1 . 2 Hz ) , 3 . 80 ( 1 H , br ) , 3 . 75 - 3 . 59 ( 2 H , m ) , 3 . 03 ( 2 H , dt , J = 6 . 7 , 1 . 8 Hz ) , 2 . 62 ( 1 H , m ) , 2 . 38 - 2 . 22 ( 2 H , m ) , 2 . 10 ( 1 H , m ) .