1 H - NMR ( CDCl 3 ) δ 8 . 62 ( 1 H , dt , J = 4 . 7 , 1 . 7 Hz ) , 7 . 51 ( 1 H , d , J = 7 . 6 Hz ) , 7 . 41 ( 1 H , dd , J = 8 . 5 , 6 . 1 Hz ) , 7 . 10 - 7 . 25 ( 3 H , m ) , 6 . 99 ( 1 H , td , J = 8 . 3 , 2 . 6 Hz ) , 4 . 54 - 4 . 67 ( 2 H , m ) , 3 . 43 - 3 . 66 ( 3 H , m ) , 3 . 03 ( 1 H , d , J = 14 . 1 Hz ) , 2 . 87 ( 1 H , br d , J = 14 . 2 Hz ) , 2 . 57 - 2 . 73 ( 3 H , m ) , 2 . 14 - 2 . 41 ( 6 H , m ) .