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