1 H - NMR ( 400 MHz , CDCl 3 ) δ = 1 . 95 ( 2 H , m , CH 2 ) , 2 . 48 ( 2 H , t , J = 6 . 78 Hz , CH 2 ) , 2 . 52 ( 2 H , t , J = 6 . 46 Hz , CH 2 ) , 2 . 64 ( 4 H , t , J = 5 . 01 Hz , 2 CH 2 ) , 3 . 23 ( 4 H , t , J = 5 . 00 Hz , 2 CH 2 ) , 6 . 78 - 7 . 64 ( 6 H , m , Ph ) , 8 . 55 ( 1 H , bs , NH ) ;