Synthesis of Acetanilide

Synthesis of Acetanilide By Rick Whitely April 9, 2013 Organic Chemistry lab 1 Professor J. Hutchison Recrystallization is a common method of purifying thoroughgoing substances through the differences in solubility at different temperature. In this audition, phenylacetamide was produced by acetylation of aniline with acetic anhydride. The crude acetanilide was dissolved in a solving in a heated irrigate bath. The solution was cooled slowly in an ice bath as crystals form out.As the enhance crystallizes from the solution, the limiting reagent aminobenzine and the percent put up of 96% was obtained. Introduction This experiment involves four functional groups common in organic chemistry. The substrate (reactants) which are Aniline and acetic anhydride are both liquids and one of the products is solid (Acetanilide). The chemical reaction of aniline with acetic anhydride is a transformation in which products acetanilide and acetic acid are obtained. A solid product (Acetanilid e) is obtained so that it whitethorn be recrystallized and a melting point determined.The Reaction Aniline (C6H5NH2) + acetic anhydride (C4H6O3) Acetanilide (C8H9NO) + acetic acid (C2H4O2) Results and Discussion Amines can be case-hardened (Acylated, adding a Carbonyl and losing a proton) using Acetic Anhydride as a source of an Acyl group to form an Amide. The Synthesis of Acetanilide (an Amide) through a Nucleophilic Acyl Substitution (addition / elimination) reaction between Aniline (an Amine) is playing as the Nucleophile and an Acyl group from Acetic Anhydride acting as the Electrophile.The instrument The desired product is isolated from its impurities by differences in solubility. Soluble impurities await in the cold solvent after recrystallization. The desired product should be as soluble as possible in hot solvent and as insoluble as possible in cold solvent. The extract of solvent is therefore critical to the successful recrystallization which in this experiment, water was utilize as the solvent because of its solubility. The calculated percent yield was 96%. Procedures Acetic anhydride (1mL, 10. 8) was added in several small portions along with 6 mL of deionized water to (0. 1 g, 1. 08 m seawall) of aniline. The immediate formation of a solid precipitate was observed. after adding 20mL of deionized water to the mixture, it was then heated until all of the existent was dissolved. A polycrystalline solid was obtained while cooling to room temperature, then filtered and washed with 2mL of chilled water. The material was allowed to dry for approximately 15 minutes and (0. 9795 g, 96%) of Acetanilide was recovered. Calculations Moles of Aniline 0. 7 g C6H5NH2 / X x 93. 3 g C6H5NH2 / 1 bulwarke = 0. 7g / 93. 13 g x X 93. 13 g / 93. 13 g = X = . 0075 mol x 1000 = 7. 5 mmol Moles of acetic anhydride 1. 08 g C4H6O3 / X x 102. 09 g / 1 mol = 1. 08 g / 102. 09 g x X 102. 09 g / 102. 09 g = X = 0. 0106 mol 1 mL x 1. 08 g / 1 mL = 1. 08 g Limiting Reagent 0. 7 g C6H5NH2 x 1 mol C6H5NH2/93. 13 g = 1 mol C8H9NO/ 1 mol C6H5NH2 x 135. 17 g C8H9NO/1 mol C8H9NO = 1. 016 g C8H9NO The limiting reagent is Aniline. throng of product .9795 g Acetanilide x 1 mol/135. 17 g Acetanilide = 0. 0073 mol Percent Yield Percent yield =