R3 is 1 3 groups independently selected from {HEAD ~ the group} consisting of lower alkyl, lower alkoxy, COOH, {TAIL ~ NO2}, NR4 R5, OH or halogeno 
consisting of
R3 is 1 3 groups independently selected from { HEAD ~ the group } consisting of lower alkyl , lower alkoxy , COOH , { TAIL ~ NO2 } , NR4 R5 , OH or halogeno
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH