Question

Section C: Predicting mechanisms and miscellaneous (5 x 10 = 50 pts) 13. An Organic Chemistry (II) student from Broward college South campus did a research on over the counter drug "Ketoprofen" and reported the sequence of ktoprofen synthesis as shown below. In this sequence some of the intermediate product is blocked. You, as an Organic Chemistry (11) student can predict the structure of the blocked intermediate. Please provide the structure of the intermediates and the final product as well. KETOPROFEN SYNTHESIS ОН SOC! CH,CH BE AIB, AICI, Benzoic Acid (3-Ethyl-phenyl)-phenyl-methanone A Br. со MO Ether Br (341-Bromo-ethylphenyl- phenyl-methanone 14. A) Starting from aniline, how will you prepare p-amino toluene. Provide all the steps involved in the process.

Answer 1

Q-13

O= o 08 OH SOCI2 CI CH3CH2Br AICI: AlBr3 4 2 3 Br2 Br MgBr Mg Ether 6 5 CO OH vigyorolt 7 8

Reaction of benzoic acid(1) with SOCl₂ converts the acid to acyl chloride. The reaction of the acyl chloride(2) with benzene and AlCl₃(lewis acid) is the friedel-crafts acylation reaction. The reaction of benzophenone(3) with ethyl bromide and AlBr₃ is the friedel-crafts alkylation reaction. The reaction of compound-5 with Mg leads to the formation of a grignard reagent which then reacts with CO₂ to give the compound-7, this on hydrolysis gives the final product(8).

Q-14

0 0 NH2 NH CH3 NH2 NH CH3 NH3 CH3-CI H30* NaOH CH3 CI Pyridine AICI: CH3 CH3 CH3

Step-1 - Protection of aniline -NH₂ group with AcCl. (This is done because friedel-crafts reaction is not possible with aniline. In aniline ,the -NH₂ nitrogen reacts with the lewis acid, this changes the activating -NH₂ group to a deactivating group and thus friedel-crafts reaction cannot occur on the ring.)

Step-2 - Friedel-crafts alkylation with methyl chloride and AlCl₃(lewis acid).

Step-3- Removal of the protecting group by hydrolysis of amide.