remifentanil [ 3-(4-methoxycarbonyl-4-((1-oxopropyl)phenylamino)-1-piperidine)propanoic acid methyl ester,GI 87084B,Abbott brand of remifentanil,GI-87084B,GI87084B,Glaxo Wellcome brand of remifentanil,GlaxoSmithKline brand of remifentanil,Ultiva,remifentanil hydrochloride,remifentanil monohydrochloride ] PA refers to mono-HCl; structure in first source