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