wherein R1 is hydrogen, fluoro, {HEAD ~ chloro}, or methyl; and R2 is C4 CS branched {TAIL ~ alkyl} 
wherein R1 is hydrogen , fluoro , { HEAD ~ chloro } , or methyl ; and R2 is C4 CS branched { TAIL ~ alkyl }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL