Microwave-assisted synthesis of fused tricyclic pyrazino(1,2-a)indole derivatives

A microwave-assisted expedient route for the synthesis of novel 3-phenylpyrazino(1,2-a)indol-1(2H)-one derivatives is reported. The method has advantages such as accelerated reaction rate, excellent yields, simplicity of operation, and is eco-friendly. Microwave heating of ammonium acetate generates the NH3 nucleophile required for the cyclization reaction and acetic acid.