1 H - NMR ( 400 MHz , CDCl 3 ) δ : 7 . 59 ( 1 H , d , J = 8 . 8 Hz ) , 7 . 52 ( 1 H , s ) , 7 . 24 ( 3 H , s ) , 7 . 13 ( 2 H , d , J = 7 . 6 Hz ) , 6 . 79 ( 1 H , s ) , 6 . 74 ( 1 H , d , J = 7 . 6 Hz ) , 6 . 64 ( 1 H , d , J = 7 . 6 Hz ) , 4 . 68 ( 2 H , t , J = 9 . 2 Hz ) , 3 . 16 ( 2 H , t , J = 8 . 8 Hz ) , 2 . 87 - 2 . 82 ( 4 H , m ) , 2 . 34 ( 3 H , s ) , 2 . 06 ( 2 H , q , J = 7 . 6 Hz ) .