Unformatted text preview: electrons in each step. Cl + 1. AlCl 3 2. H 3 O + 4. Pyrrole undergoes Electrophilic aromatic substitution preferentially at the 2-position as illustrated below for 2-nitropyrrole. [Note that pyrrole reacts under milder reaction conditions than benzene does. Here, nitric acid in acetic acid instead of nitric acid in sulfuric acid is sufficient.] N H HNO 3 CH 3 COOH, 5°C N H NO 2 Write resonance structures for the intermediate formed by attack at 2- and 3-positions of pyrrole. From the examination of the intermediates offer an explanation for the preferential nitration at the 2-position. 5. Write down the major product of each of the following reactions. Br O B O n-Bu + Pd(PPh 3 ) 4 NaOH Br (CH 3 CH 2 ) 2 CuLi...
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- Spring '09
- Benzene, Sulfuric acid, Electrophilic aromatic substitution, pyrrole