cocaine reverse ester cocaine reverse ester cocaine reverse ester, (also known as reverse ester cocaine or rec) is a tropane derivative drug which is a reverse ester of cocaine, with the 2-cooch3 methoxycarbonyl group swapped to an isomeric ococh3 acetoxy group. it was synthesised because of the observation that the reverse ester pairs of several structurally related substances show similar activity to each other (see e.g. methylphenidate vs phacetoperane, pethidine vs desmethylprodine). cocaine reverse ester however did not produce cocaine-like stimulant effects in animal studies, and is also illegal in many jurisdictions as a structural isomer of cocaine; nevertheless it has attracted attention from vendors of quasi-legal designer drugs as a potential alternative to cocaine. cocaine reverse esteridentifiers iupac name octan-3-yl] benzoate cas number33780-46-0pubchem cid9995139chemspider8170720chemical and physical dataformulac17h21no4molar mass303.358 g·mol−13d model (jsmol)interactive image smiles cc(=o)o1(cc2ccc1n2c)oc(=o)c3=cc=cc=c3 inchi inchi=1s/c17h21no4/c1-11(19)21-16-14-9-8-13(18(14)2)10-15(16)22-17(20)12-6-4-3-5-7-12/h3-7,13-16h,8-10h2,1-2h3/t13?,14?,15-,16+/m0/s1key:qavjuwlvuknzfv-sshxobkssa-n