1 H - NMR ( 400 MHz , CDCl 3 ) δ : 7 . 61 ( 1 H , dd , J = 8 . 8 Hz ) , 7 . 54 ( 1 H , s ) , 7 . 47 ( 2 H , dd , J = 8 . 0 Hz ) , 7 . 37 ( 5 H , m ) , 7 . 13 ( 1 H , t , J = 7 . 6 Hz ) , 7 . 00 ( 2 H , d , J = 8 . 8 Hz ) , 6 . 96 ( 2 H , d , J = 9 . 2 Hz ) , 6 . 90 ( 2 H , d , J = 6 . 8 Hz ) , 6 . 77 ( 1 H , d , J = 8 . 4 Hz ) , 5 . 20 ( 2 H , s ) , 4 . 69 ( 2 H , t , J = 8 . 8 Hz ) , 3 . 19 ( 2 H , t , J = 8 . 8 Hz ) .