1 H - NMR ( 300 MHz , CDCl 3 ) σ 1 . 11 ( t , 3 H , J = 6 . 9 Hz ) , 1 . 39 ( t , 3 H , J = 6 . 9 Hz ) , 1 . 60 ( d , 3 H , J = 6 . 0 Hz ) , 2 . 04 ( s , 3 H ) , 2 . 29 ( s , 3 H ) , 2 . 78 ( s , 3 H ) , 3 . 33 ( q , 2 H , J = 6 . 9 Hz ) , 4 . 38 ( q , 2 H , J = 6 . 9 Hz ) , 5 . 12 ( q , 1 H , J = 6 . 0 Hz ) , 7 . 10 - 7 . 24 ( m , 3 H ) ;