1: With toluene-4-sulfonic acid in benzene 4 h; Heating; 2: With oxygen in benzene T=20°C; 2 h; 3: With sodium hydroxide in ethanol T=20°C; Title compound not separated from byproducts;

1: With toluene-4-sulfonic acid in benzene 4 h; Heating; 2: With oxygen in benzene T=20°C; 2 h; Title compound not separated from byproducts;