ANAL 1.1 SYNTHESIS OF ANALGESICS: ASPIRIN & ACETAMINOPHEN EXPERIMENTAL TECHNIQUES REQUIRED Recrystallisation

INTRODUCTION In this two week experiment you will be synthesising and purifying two common analgesics (painkillers) aspirin and acetaminophen. Aspirin is prepared by the O-acylation (i.e. add an acyl group to an oxygen) of salicylic acid. Similarly, acetaminophen is prepared by the N-acylation (i.e. add an acyl group to a nitrogen) of p-aminophenol. Note the similarity between the two reactions. The crude samples will be purified by recrystallisation and the melting points of the products measured as a means of checking their identity and purity. The purpose of this experiment is to prepare the analgesics (i.e. practice the art of chemical synthesis), to practice the fundamentally important skill of purification by efficient recrystallisation, and apply the previously learned technique of melting point determination. Try to have the two crude products prepared by the end of the first week.