1 H - NMR ( 400 MHz , CDCl 3 ) δ = 1 . 97 ( 2 H , m , CH 2 ) , 2 . 51 ( 2 H , t , J = 6 . 93 Hz , CH 2 ) , 2 . 55 ( 2 H , t , J = 6 . 66 Hz , CH 2 ) , 2 . 67 ( 4 H , s , 2 CH 2 ) , 3 . 08 ( 4 H , s , 2 CH 2 ) , 6 . 85 - 8 . 28 ( 7 H , m , Ph ) , 8 . 34 ( 1 H , bs , NH ) ;