Schlittler-Muller modification

Simple permutation where the amine and the aldehyde switch places for the two reactants in comparison to the Pomeranz-Fritsch reaction. 

Hudson, A. Pomeranz-Fritsch Reaction. In Name Reactions in Heterocyclic Chemistry, Li, J. J., Corey, E. J., Eds. Wiley Sons Hoboken, NJ, 2005, 480-486. (Review). 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 207, Springer-Verlag Berlin Heidelberg 2009 

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W. J. Gensler, Organic Reactions 6,4 Schlittler-Muller Modification ... 

Jackson modification and Schlittler-Muller modification. The Fischer modification involves the treatment of benzalaminoacetal with fuming sulfuric acid, whereas Bobbitt modification produces tetrahydroisoquinoline derivative through the hydrogenation of an imine intermediate in situ to an aminoacetal, which in turn is converted into product by the acid-promoted cyclization and hydrogenation. This modification for tetrahydroisoquinoline is also known as the Pomeranz-Fritsch-Bobbitt cyclization. The Schlittler-Muller modification involves the preparation of benzalaminoacetal from benzyl amines and gly-oxal semiacetal. In addition, this reaction has been extended to prepare other types of aromatic heterocycles, such as thieno[2,3-c] and thieno[3,2-c]pyridines by intromolecular cyclization to thiophene ring. ... 

This reaction has been modified to different variants, such as the Bobbitt modification, Fischer modification, and the Schlittler-Muller modification. In addition, different acids have been used as the promoters for this reaction. 

Schlittler, E., Muller, J. A new modification of the isoquinoline synthesis according to Pomeranz-Fritsch. Helv. Chim. Acta 1948, 31,914-924. 

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