Paracetamol – Synthesis and Uses Discovered in 1877 by Harmon Northrop Morse at John Hopkins University, paracetamol was one of several aniline derivatives that were found to have analgesic properties and antipyretics (Brodie 23). It was first synthesized by reduction of p-nitrophenol with tin in glacial acetic acid; however, it was used as a medicine only ten years later (Bertolini 264). Initially, phenacetin, a closely related compound that showed similar physiological effects, became the popular over-the-counter headache medication (Bertolini 251). However, later research by Brodie and Axelrod in 1949 found that phenacetin was actually metabolized into acetaminophen within the body (Brodie and Axelrod 60). Subsequently, acetaminophen quickly replaced phenacetin and remains one of the most common over-the-counter medications for reducing fever and relieving pain. Found in pharmacies around the world, acetaminophen is commonly known by its American brand name, Tylenol. Paracetamol is chemically called N-acetyl – p – aminophenol. The chemical structure is a six-membered aromatic ring with a hydroxyl substituent placed para to the N-acetyl substituent. As the use of acetaminophen has increased, scientists and researchers have been examining the most efficient methods to synthesize the compound. In 1997, demand for acetaminophen in the United States was estimated at 30-35 thousand tons per year (IARC 73). Global demand has been equally high in many other countries. There are numerous currently known synthetic routes that attempt to produce the compound in the most efficient manner. When determining efficiency, numerous factors must be taken into account. The most important include the cost of reagents,...... half of the paper... in light of the physiological effects of paracetmol. The compound has characteristics that mirror other analgesics and antipyretics but also exhibits unique properties that may be advantageous in certain treatment plans. Its anti-inflammatory activity is not as strong as that of other similar drugs known as NSAIDs; defined in all respects as non-steroidal anti-inflammatory drugs. The primary mechanism proposed for acetaminophen involves highly selective inhibition of an enzyme called cyclooxygenase; abbreviated COX. There are two isoenzymes of cyclooxygenase that have similar molecular weight and structure but each performs different functions. They are labeled COX-1 and COX-2. COX-1 is present in most tissues and functions more specifically in maintaining the stomach lining. It also plays other vital roles within the body such as platelet and kidney function.