Exercise 3 Add major products and write down the reaction mechanism.

3.1 H_C=N=N 3.2 Ar CO CHE 3.3 + Ph=N-0 3.4 Ph 3.5 3.6 A OONS 3.7 O-NEP 3.8 H3COC O-N= Ph. 3.9 H3C02C CN + CO2CH3 4.10