Benzanilide synthesis

synthesis of benzanilide by Schotten Baumann reaction

1. Benzanilide Synthesis By: Mrs. D. R. Mali Asssitant Professor Pharmaceutical Chemistry GES’s Sir Dr. M. S. Gosavi College of Pharmaceutical Education and Research, Nashik .

2. AIM To synthesize benzanilide from aniline REFERENCES: Laboratory Manual of Organic Chemistry by Raj K. Bansal , Page No.111. Frederick George Mann and Bernard Charles Saunders, ‘Practical Organic Chemistry’, IV th edition Longman Group Limited, London, 1978, pp. 245

3. REACTION:

4. PRINCIPLE: Benzoylation : Insertion of benzoyl moiety instead of an active hydrogen atom present in hydroxyl (OH) primary amino (NH 2 ) or secondary amino group (NH ). Schotten Baumann reaction: Benzoylation of compounds those are containing active hydrogen such as Phenol, aniline, alcohol etc. form benzoyl chloride in the presence of aqueous NaOH Use: It is used as fungicide and acaricide ( pesticide that kill ticks and mites ).

5. Schotten Baumann Reaction Mechanism Step 1 : The formation of a protonated compound Step 2 : The catalyst of the reaction (i.e. the base) proceeds to absorb the acidic proton Step 3 : In the final step, the required amide product is formed along with hydrochloric acid

6. Reacrtion mechanism

7. REQUIREMENTS Chemicals :           Aniline – 2 ml 10% NaOH -30 ml Benzoyl chloride – 3 ml Cold water Hot alcohol Apparatus:        Conical flask – 250 ml  Buchner funnel Measuring cylinder Filter paper

8. PROCEDURE Place 2 ml (2.08 g) of aniline 30 ml of 10% NaOH solution in 250 ml conical flask. Add 3 ml (3.4 g) of Benzoyl chloride slowly with vigorous shaking. Cork the flask and shake for further 15-20 min or till the odour of benzoyl chloride can no longer be detected. Dilute the reaction mixture with cold water. Filter the crude benzanilide with suction on a Buchner funnel. Wash with cold water and crystallize from hot alcohol. Dry the product and calculate the percentage yield .

9. Calculation Molecular formula of aniline = C 6 H 7 N Molecular formula of benzanilide = C 13 H 11 ON Molecular weight of aniline = 93 g/mole Molecular weight of benzanilide = 197 g/mole

10. Theoretical yield: 93 g aniline forms 197 g benzanilide Therefore, 2.08 g (2 ml) aniline will form ………? (X) g benzanilide X = ( 197 × 2.08)/93 = 4.4 gs Theoretical yield = 4.4 gs Practical yield = ————- gs % Yield = (Practical Yield)/(Theoretical Yield) × 100

11. REsult Name of compound: Benzanilide Structure: IUPAC Name : N- phenylbenzamide Molecular Formula: C 13 H 11 ON Molecular Weight: 197 g/mole Theoretical Yield: 4.4 g Practical Yield: ____ g Percentage Yield: _____ % Melting point: ___° C (162 to 164 ° C)

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