1 H - NMR ( 400 MHz , CDCl 3 ) δ : 7 . 72 ( 2 H , d , J = 8 . 8 Hz ) , 7 . 49 ( 2 H , d , J = 6 . 8 Hz ) , 7 . 40 - 7 . 35 ( 3 H , m ) , 7 . 14 ( 1 H , d , J = 8 . 4 Hz ) , 6 . 89 ( 2 H , d , J = 8 . 8 Hz ) , 6 . 80 ( 1 H , s ) , 6 . 66 ( 1 H , d , J = 7 . 2 Hz ) , 5 . 20 ( 2 H , s ) , 3 . 87 ( 3 H , s ) , 2 . 89 - 2 . 85 ( 4 H , m ) , 2 . 08 ( 2 H , q , J = 7 . 2 Hz ) .