1 H - NMR ( 400 MHz , CDCl 3 ) δ = 1 . 88 ( 2 H , m , CH 2 ) , 2 . 43 ( 2 H , t , J = 6 . 54 Hz , CH 2 ) , 2 . 50 ( 2 H , t , J = 6 . 14 Hz , CH 2 ) , 2 . 80 ( 4 H , s , 2 CH 2 ) , 3 . 05 ( 4 H , s , 2 CH 2 ) , 6 . 91 - 7 . 73 ( 6 H , m , Ph ) , 9 . 14 ( 1 H , bs , NH ) ;