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