1 H NMR ( CDCl 3 ) : δ 9 . 96 ( s , 1 H , - CHO ) , 7 . 80 ( d , J = 8 . 7 Hz , 2 H , H - Ar ) , 7 . 38 ( d , J = 8 . 7 Hz , 2 H , H - Ar ) , 2 . 98 ( m , 1 H , - CH ) , 1 . 27 ( d , J = 6 . 9 Hz , 6 H , - CH 3 )