N-acetyl-para-aminophenol

Tylenol paracetamol N-acetyl-para-aminophenol para-acetyl-amino-phenol... 

Paracetamol (known as acetaminophen in the USA) is N-acetyl-para-aminophenol (Figure 25.11). It has the same detoxification pathways as phenol and also carries the risk of inducing methemoglobinemia. To be on the safe side, it should not be used as an intravenous analgesic during a full-face phenol peel, so as not to saturate the detoxification pathways. Paracetamol is also an intermediate in the pathway for detoxification of aniline derivatives, before hepatic glucuronide and sulfate conjugation allow them to... 

The presence of prilocaine is a (relative) contraindication to combining EMLA with products with a potential to cause methemoglobinemia. Combined use with paracetamol (acetaminophen), for example, is to be avoided. Paracetamol is a derivative of phenol (N-acetyl-para-aminophenol) and is subject to the same detoxification pathways as phenol. Paracetamol inherits its properties of causing methemoglobinemia from phenol. Large doses of EMLA (>600 mg of prilocaine, or four 5 g tubes) should therefore not be applied prior to phenol. 

Chemical Name N-acetyl-para-aminophenol Chemical Structure see Figure 61.1 Formula CgH NO ... 

N-substituted phenylhydroxylamine derivatives, e.g. N-acetyl and N-sulphonic acid, also form the para-aminophenol", but more bulky groups prevent reaction, it is thought by steric hindrance to the approach of the hydronium ion. -substituted phenylhydroxylamines, on the other hand form only the ortho product, it is thought via an intramolecular rearrangement, e.g. 

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