1 H NMR ( 300 MHz , CDCl 3 ) δ 1 . 62 ( m , 2 H ) , 1 . 73 ( m , 2 H ) , 1 . 90 ( m , 4 H ) , 2 . 16 ( s , 3 H ) , 2 . 23 ( br t , 2 H , J = 6 . 8 Hz ) , 2 . 47 ( m , 1 H ) , 2 . 80 ( m , 2 H ) , 3 . 98 ( s , 3 H ) , 4 . 19 ( t , 2 H , J = 7 . 2 Hz ) , 6 . 94 ( m , 1 H ) , 7 . 06 ( dd , 1 H , J = 7 . 2 , 5 . 1 Hz ) , 7 . 21 - 7 . 39 ( m , 6 H ) , 7 . 50 ( m , 1 H ) , 7 . 82 ( m , 1 H ) , 7 . 88 ( dd , 1 H , J = 7 . 3 , 1 . 8 Hz ) , 8 . 34 ( dd , 1 H , J = 5 . 0 , 1 . 8 Hz ) ; MS ( m / e , M +): 483 ( M +), 468 , 252 , 231 , 70 .