# The relative reactivities of acyl compounds towards nucleophilic substitution are in the order of :

$\begin {array} {1 1} (1)\;Acyl\: chloride> Ester>Acid\: anhydride>Amide \\ (2)\;Acyl\: chloride> Acid\: anhydride>Ester>Amide\\ (3)\;Ester>Acyl\: chloride>Amide>Acid\: anhydride \\ (4)\;Acid\: anhydride>Amide>Ester>Acyl\: chloride \end {array}$