1.1: 5 h / |Reflux 2.1: |Reflux 3.1: diphenylether / 2.5 h / 270 °C 3.2: 18 h / 20 °C 4.1: ammonium hydroxide / water; ethyl acetate View Scheme

1.1: 5 h / |Reflux 2.1: |Reflux 3.1: diphenylether / 2.5 h / 270 °C 3.2: 18 h / 20 °C 4.1: ammonium hydroxide / water; ethyl acetate 5.1: trifluoroacetic acid / |Inert atmosphere; |Reflux 5.2: 2.5 h / |Inert atmosphere; |Reflux 5.3: 1.5 h / |Inert atmosphere; |Reflux View Scheme

Heating;

1.5 h; Heating;