1 H - NMR ( 400 MHz , CDCl 3 ) δ = 2 . 48 - 2 . 60 ( m , 8 H , 4 CH 2 ) , 2 . 70 ( brs , 2 H , CH 2 ) , 3 . 45 ( s , 2 H , CH 2 ( benzyl ) ) , 3 . 77 ( s , 3 H , OMe ) , 3 . 93 ( s , 1 H , CH 2 a ) , 3 . 94 ( s , 1 H , CH 2 b ) , 4 . 05 - 4 . 08 ( m , 1 H , CH ) , 6 . 81 - 7 . 44 ( m , 7 H , Ph ) .