1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 43 ( m , 2 H ) , 1 . 71 ( brd , 2 H ) , 1 . 85 - 2 . 01 ( m , 4 H ) , 2 . 18 ( s , 3 H ) , 2 . 16 ( t , 2 H ) , 2 . 41 ( m , 1 H ) , 2 . 72 ( br , 2 H ) , 4 . 44 ( t , 2 H ) , 6 . 91 ( d , 1 H ) , 7 . 23 - 7 . 32 ( m , 4 H ) , 7 . 49 - 7 . 53 ( m , 3 H ) , 7 . 83 ( m , 1 H ) , 7 . 85 ( d , 2 H ) , 7 . 94 ( d , 2 H ) ; MS ( m / e , M +): 477