a) By consideration of the reactivities of the carbonyl groups of the dione and the amino groups of the hydrazine, explain why regioisomer 7 is the main reaction product. (3 marks)

b) Provide a mechanism for the above reaction to give 7; the aryl groups may be abbreviated as Ar and Ar’. 

 

NH, H,C cat. HCI N-N H,C ethanol (solvent) heat HN-S=o