1 H - NMR ( 400 MHz , CDCl 3 ) δ = 2 . 51 ( 2 H , t , J = 5 . 75 Hz , CH 2 ) , 2 . 65 ( 6 H , s , 3 CH 2 ) , 2 . 72 ( 4 H , t , J = 4 . 93 Hz , 2 CH 2 ) , 3 . 56 ( 2 H , s , CH 2 ( benzyl ) ) , 7 . 22 - 7 . 67 ( 6 H , m , Ph ) , 11 . 36 ( 1 H , bs , NH ) ;