CHM-233 Lecture Notes - Williamson Ether Synthesis, Phenacetin, Paracetamol
Document Summary
From acetaminophen, phenacetin was prepared by williamson ether synthesis, under acidic conditions, in 11% yield. The product was characterized by h nmr and ir. Preparation of phenacetin: acetaminophen (1. 3g,), potassium carbonate (2. 5g), 2- butanone (15 ml), iodoethane (1. 0 ml) were mixed and a boiling chip was added. The mixture was refluxed for 1 hour and then the contents were filtered into a separatory funnel, rinsed with ether (2x 5ml) and washed with both aqueous naoh (20 ml, 5%) and water (20 ml). The resulting solution was dried with magnesium sulfate, and the ether was evaporated by rotatory evaporation. The product was recrystallized from water and collected by vacuum filtration as a bright white solid (0. 1717 g, 11%). mp 125-128 oc (lit1 value 135 o c). H nmr (400 mhz): 8. 0 (s,1h, h2), 6. 7-7. 5 (dd,4h: h3, h4, h5, h6), 3. 75-4. 20 (q, 2h, h7), 1. 80-2. 20 (dd, 3h, h1 ), 1. 25-
