{HEAD ~ A diphenylamine} 1, wherein R6 and {TAIL ~ R7} are each hydrogen 
wherein
{ HEAD ~ A diphenylamine } 1 , wherein R6 and { TAIL ~ R7 } are each hydrogen
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH