1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 64 ( m , 2 H ) , 1 . 78 ( brd , 2 H ) , 1 . 99 ( brt , 2 H ) , 2 . 17 ( s , 3 H ) , 2 . 36 ( m , 1 H ) , 2 . 37 - 2 . 48 ( m , 4 H ) , 2 . 94 ( brd , 2 H ) , 4 . 80 ( t , 2 H ) , 6 . 94 ( d , 1 H , J = 7 . 6 Hz ) , 7 . 05 ( dd , 1 H ) , 7 . 25 ( m , 1 H ) , 7 . 35 - 7 . 50 ( m , 5 H ) , 7 . 74 ( d , 2 H , J = 6 . 0 Hz ) , 8 . 18 ( d , 1 H , J = 7 . 5 Hz ) , 8 . 50 ( d , 2 H ) ; MS ( m / e , M +): 453