A compound 3 wherein R2 is hydrogen, R4 and R5 are hydrogen or methyl, and {HEAD ~ X} is hydrogen, {TAIL ~ fluoro} or chloro 
is
A compound 3 wherein R2 is hydrogen , R4 and R5 are hydrogen or methyl , and { HEAD ~ X } is hydrogen , { TAIL ~ fluoro } or chloro
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH