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