Synthesis of Paracetamol,

Industrial preparation of paracetamol usually proceeds from nitrobenzene. In the laboratory, paracetamol is easily prepared by nitrating phenol with sodium nitrate, separating the desired p-nitrophenol from the ortho- byproduct, and reducing the nitro group with sodium borohydride. The resultant p-aminophenol is then acetylated with acetic anhydride. In this reaction, phenol is strongly activating, thus the reaction requires only mild conditions (cf. the nitration of benzene).