{HEAD ~ R1} is fluorine, chlorine, {TAIL ~ iodine}, o bromo, m bromo, lower alkoxy, acyloxy, nitro, hydroxy, amino, lower alkylamino, di lower alkylamino 
is
{ HEAD ~ R1 } is fluorine , chlorine , { TAIL ~ iodine } , o bromo , m bromo , lower alkoxy , acyloxy , nitro , hydroxy , amino , lower alkylamino , di lower alkylamino
HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH