1 H NMR ( CDCl 3 ) δ 8 . 60 ( 1 H , br d , J = 4 . 6 Hz ) , 7 . 65 ( 1 H , br ) , 7 . 45 ( 1 H , d , J = 2 . 0 Hz ) , 7 . 42 ( 1 H , d , J = 7 . 9 Hz ) , 7 . 34 ( 1 H , d , J = 2 . 0 Hz ) , 7 . 23 ( 1 H , dd , J = 7 . 9 , 4 . 6 Hz ) , 4 . 83 - 4 . 65 ( 5 H , m ) , 4 . 32 ( 1 H , s ) , 3 . 82 ( 1 H , br ) , 2 . 52 ( 1 H , m ) , 2 . 42 - 2 . 21 ( 2 H , m ) , 2 . 00 ( 1 H , m ) .