1. Outline a mechanism for Step 1. (1 mark) 
2. What is the name for the type of reaction that has occurred in Step 1? (1 mark) 
3. Outline a mechanism for Step 2. (4 marks) 
4. Account for the selectivity seen in the electrophilic aromatic substitution reaction that has occurred in Step 3. Give a brief mechanistic justification of your answer. (4 marks)
5. n
   

'N' CI NH3 / H20 N' CI Step 1 N' NH2 2,3-dichloropyrazine Br Step 2 H heat in ethanol (solvent) CI I Br2 / acetic acid (solvent) N Step 3 E Br