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