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Eschweiler-Clarke Methylation

Published Online: 15 SEP 2010

DOI: 10.1002/9780470638859.conrr220

Comprehensive Organic Name Reactions and Reagents

Comprehensive Organic Name Reactions and Reagents

How to Cite

2010. Eschweiler-Clarke Methylation. Comprehensive Organic Name Reactions and Reagents. 220:1009–1012.

Publication History

  1. Published Online: 15 SEP 2010

Abstract

The preparation of tertiary methylamines from primary or secondary amines by means of the treatment of those amines with an excess amount of aqueous formaldehyde and formic acid is generally known as the Eschweiler–Clarke methylation. The study finds that in this reaction, the formate anion donates its proton to reduce the imine or iminium salt, so that carbon dioxide is evolved. Thus this process is known as reductive amination of formaldehyde. The reductive amination that occurs on phenylethylamine and results in the formation of tetrahydroisoquinolines is also referred to as the Clarke–Eschweiler cyclization. The reaction has application in the methylation of primary and secondary amines.

Keywords:

  • tertiary methylamines;
  • carbon dioxide;
  • phenylethylamine;
  • formaldehyde