Experiment 34A: Hypochlorite Oxidation of Methyl Ketones by the Haloform Reaction: Benzoic Acid

Objective:
To practice the Haloform reaction as synthetic rout to form benzoic acid
To understand the mechanis that provide chorine from NaOH
To obtain the melting point and FTIR spectrum of benzoic acid

Experimental Procedure:
The procedure was followed as described in Mayo, pages 405 -406, with the modifications given on Blackboard. Additional modifications to the procedure included the following:

* The filtered product was left on the Hirsch funnel for 1 5 min * The amount of Na2SO3 was increased from 15 to35 mg * The amount of Acetophenone was increased from 15 to35 mg * The amount of Na2SO3 was increased from 90 μL, from 60 μL. * The amount of Sodium hypoclorite was increased to 3.2 mg

Reaction scheme

Data and Results:
Physical properties Compound | Formula | MW | Amount | mmol | Mp 0C | Bp 0C | d | nD | Acetophenone | C₆H₅COCH₃ | 120.16 | 90 μL. | 77 | 20.7 | 2.2.6 | 1.03 | 1.5372 | Aquous NaOCl | NaOCl | 74.442 | 3.2mL | | 18 | 101 | 1.11 | | Sodium sulfite | Na2SO3 | 120.6 | 35mg | | | 33.4 | | | Benzoic acid | C6H5COOH | 122.12 | 94mg | 77 | 121.0 | 249 | | | Chloroform | CHCl3 | 119.38 | 92mg | | | | | | Water | H2O | 18.015 | 1.5mL | | 32 | 100 | 1.00 | |

Observations: * Acetophenone and NaOCl were clear liquids * Sodium Sulfite was a whote powder * A yellow greasy liquid was found at the bottom of the conical vial when ether was added * The reaction mixture became acidic after 15 drops of HCl were added * Bubbles came out of the reaction mixture and a light white precipitate was observed when HCL was added * The product was benzoic acid and its appearance after filtration was white small chrystals * The weight of the product was 51mg * The melting point of