1 H NMR ( 399 . 9 MHz , CDCl 3 ) δ 1 . 76 ( 2 H , m ) , 1 . 92 - 2 . 01 ( 4 H , m ) , 2 . 57 ( 6 H , m ) , 2 . 74 - 2 . 82 ( 4 H , m ) , 3 . 11 ( 2 H , m ) , 3 . 25 ( 4 H , m ) , 4 . 00 ( 2 H , t ) , 4 . 37 ( 2 H , m ) , 6 . 85 ( 2 H , d ) , 7 . 12 ( 3 H , m ) , 7 . 93 ( 1 H , d ) ; m / z = 568 [ M + H ] +.