C6H5NH2(l) + (CH3CO)2O -?> C6H5NHCOCH3(s)+ CH3COOH(l)

Looking at the reaction, you notice that the conjugate base of acetic acid is acetate. While acetic acid anhydride is dangerous salting out the acetate with an Arrhenius salt such as sodium bicarbonate yields sodium acetate, which is a harmless salt often added to food products in place of vinegar. Why was this not chosen as our starting material?