1 H - NMR ( 300 MHz , CDCl 3 ) σ 1 . 41 ( t , 3 H , J = 7 . 2 Hz ) , 2 . 53 ( s , 3 H ) , 3 . 89 ( s , 3 H ) , 4 . 37 ( q , 2 H , J = 7 . 2 Hz ) , 7 . 43 - 7 . 46 ( m , 3 H ) , 7 . 61 ( d , 1 H , J = 1 . 8 Hz ) ;