piprozolin piprozolin piprozolin (or piprozoline) is a medication for bile therapy. piprozolinclinical dataatc codea05ax01 (who) identifiers iupac name ethyl (2z)-2-(3-ethyl-4-oxo-5-piperidin-1-yl-1,3-thiazolidin-2-ylidene)acetate cas number17243-64-0pubchem cid5911905chemspider4744588 yunii7786w0vv8mchemblchembl2105231echa infocard100.037.512 chemical and physical dataformulac14h22n2o3smolar mass298.40 g·mol−1 inchi inchi=1s/c14h22n2o3s/c1-3-16-11(10-12(17)19-4-2)20-14(13(16)18)15-8-6-5-7-9-15/h10,14h,3-9h2,1-2h3/b11-10- ykey:uaxybjsapftpnb-khpplwfesa-n y (verify) synthesis compared to fenclozic acid, piprozolin shows choleretic rather than anti-inflammatory activity. that is, the compound is useful in those conditions where the flow of bile is to be increased. piprozolin synthesis: condensation of ethyl mercaptoacetate with ethyl cyanoacetate leads to thiazolinone (4); an intermediate such as 3, involving addition of the mercaptide to the nitrile function can reasonably be invoked. m/ethylation with di(m)ethyl sulfate proceeds on nitrogen with the concomitant shift of the enamine to afford olefin (5). bromination of the active methylene (6) followed by displacement of halogen by piperidine affords the choleretic piprozolin (7).