1 H - NMR ( 400 MHz , CDCl 3 ) δ 0 . 84 - 1 . 97 ( m , 36 H ) , 2 . 90 - 2 . 95 ( m , 2 H ) , 3 . 92 ( d , J = 4 . 8 Hz , 2 H ) , 6 . 99 ( dd , J = 6 . 0 , 1 . 2 Hz , 1 H ) , 7 . 26 - 7 . 28 ( m , 1 H ) , 7 . 71 ( d , J = 6 . 6 Hz , 1 H )