Electrophilic Aromatic Substitution: Multi-Step Synthesis

Suggest a synthetic scheme for the conversion shown on the left. Work each problem backwards, and draw the structures of the two intermediates required for the conversion, and the reaction conditions necessary for each step.
Click the mouse on the buttons to view the synthetic logic for each step, the structures of the intermediates and the solution to the problem.

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Working backwards, this molecule is 3-bromoaniline, and we must begin with benzene. Both groups in this molecule are ortho-para- directing, yet the substituents are meta, suggesting that one of the groups has been transformed from some meta-directing functionality. Arylamines can be prepared from arylnitro compounds by simple reduction. Suggest a structure for the preceding intermediate and provide a method for its conversion into the final product.

Working backwards, this molecule is 3-bromoaniline, and we must begin with benzene. Both groups in this molecule are ortho-para- directing, yet the substituents are meta, suggesting that one of the groups has been transformed from some meta-directing functionality. Arylamines can be prepared from arylnitro compounds by simple reduction. Next, suggest a synthesis of 3-nitro-1-bromobenzene.

3-Nitro-1-bromobenzene can be prepared most directly by the bromination of nitrobenzene with Br₂/FeBr₃.

3-Nitro-1-bromobenzene can be prepared most directly by the bromination of nitrobenzene with Br₂/FeBr₃. Next, suggest a synthesis of nitrobenzene, beginning with benzene.

Benzene is first nitrated by reaction with HNO₃/H₂SO₄. In a second step, this is brominated in the meta-position and then the nitro group is converted to an arylamine by reduction with acidic SnCl₂to give the desired product.