1 H - NMR ( CDCl 3 ; δ ppm ) : 7 . 50 - 7 . 47 ( m , 2 H ) , 7 . 00 - 6 . 93 ( m , 2 H ) , 5 . 08 - 5 . 06 ( m , 1 H ) , 4 . 17 ( t , J = 6 . 7 Hz , 1 H ) , 4 . 09 - 4 . 01 ( m , 3 H ) , 3 . 95 ( dt , J = 4 . 0 Hz , J = 8 . 3 Hz , 1 H ) , 2 . 28 - 2 . 17 ( m , 2 H ) , 1 . 89 - 1 . 84 ( m , 2 H ) , 1 . 52 - 1 . 37 ( m , 4 H ) , 0 . 95 ( t , J = 7 . 3 Hz , 3 H ) .