Making a Paracetamol

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Making paracetamol
This is one of the practicals that is available at The Salters Chemistry Club for students. It has been reworked for general use here on TecHKnow Wiki Technician requirment for practical
* 4-aminophenol
* Clean appropriate size glassware
* Access to Magnetic stirrer(s)
* Buchner funnel and conical flash (filtering under vaccum) * Ice
* Hotplate/bunsen burner
* Oven (set at 45OC)
Risk Assessment
4-aminophenol and ethanoic anhydride, are both IRRITANT's- avoid contact with hands or breathing in vapours. If contact with skin or eyes wash with water: Paracetamol is dangerous in large quantities. Wear safety glasses, gloves and lab coat

How it's made
Paracetamol is one of the most common drugs used in the world, and is manufactured in huge quantities. The starting material for the commercial manufacture of paracetamol is phenol, which is nitrated to give a mixture of the ortho and para-nitrotoluene. The o-isomer is removed by steam distillation, and the p-nitro group reduced to a p-amino group. This is then acetylated to give paracetamol.

Method
* Place 2g of the 4-aminophenol into a 50cm3 conical flask, add 15cm3 of water and stir the suspension vigorously (magnetic stirrer) for a few minutes. * Add 2.2cm3 of ethanoic anhydride and continue stirring until the suspension dissolves and a precipitate (Paracetamol) eventually forms. * After 10 minutes filter the precipitate (using a buchner funnel), washing with small amounts of cold, distilled water. * After drying, the crude product should be placed in a clean 100cm3 conical flask and recrystalised by heating until it just dissolves in approximately 20cm3 of water. * Cool the flask in ice until crystals of the purified paracetamol appear. * Filter the crystals under vacuum, dry in a warm oven and then record the melting point and compare with standard paracetamol tablets (~170oC). * Repeat...
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