Synthesis of 2H-pyrrolo[3,4-C]quinoline via an Aldol/Van Leusen/Staudinger/aza-Wittig sequence

<p>An aldol/van Leusen/Staudinger/aza-Wittig reaction for the preparation of the derivatives of 2H-pyrrolo[3,4-c]quinolines from 2-azidobenzaldehyde, acetyl compounds, and tosylmethyl isocyanide was developed. The process involves an aldol condensation of 2-azidobenzaldehyde with acetyl compound in base, a van Leusen reaction to form the key pyrrole intermediates, and then a Staudinger and intramolecular aza-Wittig reaction occurred with the addition of triphenylphosphine to complete the formation of pyrrolo[3,4-c]quinoline ring in high yields.