1 H - NMR ( 400 MHz , CDCl 3 ) δ = 2 . 58 ( 2 H , t , J = 5 . 76 Hz , CH 2 ) , 2 . 79 ( 6 H , t , J = 4 . 68 Hz , 3 CH 2 ) , 3 . 23 ( 4 H , t , J = 4 . 62 Hz , 2 CH 2 ) , 6 . 91 - 7 . 61 ( 6 H , m , Ph ) , 11 . 12 ( 1 H , bs , NH ) ;