{HEAD ~ Para aminoacetanilide} and para nitroacetanilide can also be used in {TAIL ~ the presence} of sodium ferrocyanide 
used in
{ HEAD ~ Para aminoacetanilide } and para nitroacetanilide can also be used in { TAIL ~ the presence } of sodium ferrocyanide
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH