Synthesis of N-Substituted 3-Amino-4-halopyridines: A Sequential Boc-Removal/Reductive Amination Mediated by Brønsted and Lewis Acids.

Autor:	Wilhelmsen CA; Department of Chemistry, 1-014 Center for Science and Technology, Syracuse University , Syracuse, New York 13244, United States., Dixon ADC; Department of Chemistry, 1-014 Center for Science and Technology, Syracuse University , Syracuse, New York 13244, United States., Chisholm JD; Department of Chemistry, 1-014 Center for Science and Technology, Syracuse University , Syracuse, New York 13244, United States., Clark DA; Department of Chemistry, 1-014 Center for Science and Technology, Syracuse University , Syracuse, New York 13244, United States.
Jazyk:	angličtina
Zdroj:	The Journal of organic chemistry [J Org Chem] 2018 Feb 02; Vol. 83 (3), pp. 1634-1642. Date of Electronic Publication: 2018 Jan 19.
DOI:	10.1021/acs.joc.7b02966
Abstrakt:	N-Substituted 3-amino-4-halopyridines are valuable synthetic intermediates, as they readily provide access to imidazopyridines and similar heterocyclic systems. The direct synthesis of N-substituted 3-amino-4-halopyridines is problematic, as reductive aminations and base-promoted alkylations are difficult in these systems. A high yielding deprotection/alkylation protocol mediated by trifluoroacetic acid and trimethylsilyl trifluoromethanesulfonate is described, providing access to a wide scope of N-substituted 3-amino-4-halopyridines. This protocol furnishes many reaction products in high purity without chromatography. Similar reductive amination conditions were also established for deactivated anilines.
Databáze:	MEDLINE
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