{HEAD ~ R1} is {TAIL ~ a hydrogen} or halogen atom, or an aliphatic, carbocyclic, carbamoyl, sulfamoyl, carbonamido, sulfonamido, alkoxycarbonyl, alkyl or arylketo, alkyl or arylsulfo, sulfo, hydroxy, acyl, nitro, cyano, amino, alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, thioalkoxy, thioalkoxyalkyl, thioaryloxy, thioaryloxyalkyl or heterocyclic group 
is
{ HEAD ~ R1 } is { TAIL ~ a hydrogen } or halogen atom , or an aliphatic , carbocyclic , carbamoyl , sulfamoyl , carbonamido , sulfonamido , alkoxycarbonyl , alkyl or arylketo , alkyl or arylsulfo , sulfo , hydroxy , acyl , nitro , cyano , amino , alkoxy , alkoxyalkyl , aryloxy , aryloxyalkyl , thioalkoxy , thioalkoxyalkyl , thioaryloxy , thioaryloxyalkyl or heterocyclic group
HEAD HEAD HEAD HEAD HEAD REL TAIL 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH