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

ABSTRACT

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.

GRAPHICAL ABSTRACT

KEYWORDS:

• Aldol/van Leusen/Staudinger/aza-Wittig reaction
• 2-azidobenzaldehyde
• 2H-pyrrolo[3,4-c]quinolones
• pyrrole

Additional information

Funding

We gratefully acknowledge financial support of this work by the National Natural Science Foundation of China (No. 21302047), the Natural Science Foundation of Hubei Province, China (No. 2014CFB635), the Key (Cultivation) Discipline Construction Project Achievements, the Project for Discipline Groups Construction of Food New Types of Industrialization of Hubei University of Arts and Science, and the Fund of Hubei 2011 Cooperative Innovation Center (No. 2011JH-2014CXTT07).