toluene-4-sulfonic acid in toluene T=80°C; Fischer cyclization;

1: sec.-butyllithium With zinc dibromide in tetrahydrofuran; hexane T=0°C; 0.166667 h; Inert atmosphere; 2: 4-EtO2CC6H4N2BF4 With zinc dibromide in tetrahydrofuran T=-60 - 25°C; Inert atmosphere; 3: With chloro-trimethyl-silane in tetrahydrofuran T=125°C; 2 h; Inert atmosphereMicrowave irradiation; regioselective reaction;

p-amino benzoic acid hydrochloride T=160°C;

1: sodium hydrogencarbonate; aqueous ethanol 2: AlCl3 / 130 °C View Scheme

1: sodium hydride / N,N-dimethyl-formamide 2: water; sodium hydroxide / ethanol 3: N-ethyl-N,N-diisopropylamine; HATU / dichloromethane 4: trifluoroacetic acid / dichloromethane View Scheme

1: With water; sodium hydroxide in ethanol T=50°C; 4 h; 2: With hydrogenchloride in ethanol; water

hydrazine