1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 47 ( 3 H , t , J = 7 . 2 Hz ) , 3 . 36 - 3 . 45 ( 2 H , m ) , 4 . 18 ( 2 H , q , J = 7 . 2 Hz ) , 4 . 62 - 4 . 71 ( 2 H , m ) , 6 . 50 ( 1 H , d , J = 2 . 3 Hz ) , 6 . 54 - 6 . 64 ( 1 H , m ) , 7 . 12 ( 1 H , d , J = 3 . 4 Hz ) , 7 . 15 - 7 . 20 ( 1 H , m ) , 7 . 34 ( 1 H , d , J = 8 . 7 Hz ) , 7 . 46 - 7 . 55 ( 2 H , m ) , 7 . 77 ( 1 H , d , J = 1 . 1 Hz ) .