6-monoacetylmorphine 6-monoacetylmorphine 6-monoacetylmorphine (6-mam, 6-acetylmorphine, or 6-am) is an opioid and also one of three active metabolites of heroin (diacetylmorphine), the others being morphine and the much less active 3-monoacetylmorphine (3-mam). 6-monoacetylmorphineclinical dataother names6-acetylmorphineroutes ofadministrationintravenousatc codenonelegal statuslegal status au: s9 (prohibited substance) uk: class a pharmacokinetic dataelimination half-life< 5 minsidentifiers iupac name 3-hydroxy-6-acetyl-(5α,6α)-7,8-didehydro-4,5-epoxy-17-methylmorphinan cas number2784-73-8 npubchem cid5462507chemspider4575434 yuniim5e47p1zchchemblchembl592009 ycomptox dashboard (epa)dtxsid60182154 echa infocard100.150.555 chemical and physical dataformulac19h21no4molar mass327.380 g·mol−13d model (jsmol)interactive image smiles cc(=o)o1/c=c\23cc4ccc(o)c5o12(ccn3c)c45 inchi inchi=1s/c19h21no4/c1-9(21)10-8-15(23)17-16-11(10)7-13-12-3-4-14(22)18(24-17)19(12,16)5-6-20(13)2/h3-4,8,12-14,18,22-23h,5-7h2,1-2h3/t12-,13+,14-,18-,19-/m0/s1 nkey:duaisainbbqdaf-lepyjnqmsa-n n ny (what is this?) (verify) pharmacology 6-mam occurs as a metabolite of heroin. once it has passed first-pass metabolism, 6-mam is then metabolized into morphine or excreted in urine. heroin is rapidly metabolized by esterase enzymes in the brain and has an extremely short half-life. it has also relatively weak affinity to μ-opioid receptors because the 3-hydroxy group, essential for effective binding to the receptor, is masked by the acetyl group. therefore, heroin acts as a pro-drug, serving as a lipophilic transporter for the systemic delivery of morphine, which actively binds with μ-opioid receptors. black tar heroin 6-mam already has a free 3-hydroxy group and shares the high lipophilicity of heroin, so it penetrates the brain just as quickly and does not need to be deacetylated at the 6-position in order to be bioactivated; this makes 6-mam somewhat more potent than heroin. availability 6-mam is rarely encountered in an isolated form due to the difficulty in selectively acetylating morphine at the 6-position without also acetylating the 3-position. however, it is found in significant amounts in black tar heroin along with heroin itself. synthesis the production of black tar heroin results in significant amounts of 6-mam in the final product. 6-mam is approximately 30 percent more active than diacetylmorphine itself, this is why despite lower heroin content, black tar heroin may be more potent than some other forms of heroin. 6-mam can be synthesized from morphine using glacial acetic acid with an organic base as a catalyst. the acetic acid must be of a high purity (97–99 per cent) for the acid to properly acetylate the morphine at the 6th position effectively creating 6-mam. acetic acid is used rather than acetic anhydride, as acetic acid is not strong enough to acetylate the phenolic 3-hydroxy group but is able to acetylate the 6-hydroxy group, thus selectively producing 6-mam rather than heroin. acetic acid is a convenient way to produce 6-mam, as acetic acid also is not a watched chemical as it is the main component of vinegar. chemistry detection in bodily fluids since 6-mam is a metabolite unique to heroin, its presence in the urine confirms heroin use. this is significant because a urine immunoassay drug screen typically tests for morphine, which is a metabolite of a number of legal and illegal opiates/opioids such as codeine, morphine sulfate, and heroin. trace amounts of 6-mam, a specific metabolite of heroin, are also excreted for approximately 6–8 hours following heroin use. so a urine specimen must be collected soon after the last heroin use; however, the presence of 6-mam suggests that heroin was used as recently as within the last day. 6-mam is naturally found in trace amounts in the brain of certain mammals.