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The Synthesis of Isoquinolines by the Pomeranz-Fritsch Reaction

  1. Walter J. Gensler

Published Online: 15 MAR 2011

DOI: 10.1002/0471264180.or006.04

Organic Reactions

Organic Reactions

How to Cite

Gensler, W. J. 2011. The Synthesis of Isoquinolines by the Pomeranz-Fritsch Reaction. Organic Reactions. 6:4:191–206.

Author Information

  1. Boston University

Publication History

  1. Published Online: 15 MAR 2011

Chemistry Terms

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Acid-catalyzed cyclization of benzalaminoacetal results in the formation of the isoquinoline nucleus. This reaction, first reported by Pomeranz and Fritsch, has been used in the synthesis of a variety of isoquinoline compounds. The process is carried out in two stages. In step one, a condensation leads to the benzalaminacetal. In step two, a ring closure leads to the isoquinoline. An alternative route involves the condensation of the corresponding benzylamine witth glyoxal semiacetal. The yield of isoquinoline products varies widely. The Pomeranz-Fritsch synthesis offers the possibility of preparing isoquinolines with the substituent groups in an orientation difficult to achieve with other methods.


  • Pomeranz-Fritsch reaction;
  • isoquinolines;
  • cyclization;
  • Schiff base;
  • acetals;
  • glyoxyl semiacetal;
  • experimental procedures