Facile regiospecific syntheses of N-α,N-1(τ)-dialkyl-l-histidines

✍ Scribed by Surendra Kumar Nayak; Vikramdeep Monga; Navneet Kaur; Rahul Jain

• Publisher: Journal of Heterocyclic Chemistry
• Year: 2007
• Tongue: English
• Weight: 316 KB
• Volume: 44
• Category: Article
• ISSN: 0022-152X
• DOI: 10.1002/jhet.5570440607

✦ Synopsis

Abstract

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Two diverse methodologies describe the first synthesis of suitably protected N‐α,N‐1(τ)‐dialkyl‐Lhistidine derivatives. Synthesis of suitably protected N‐α,N‐1(τ)‐dialkyl‐L‐histidines 7‐9 containing different alkyl groups at the N‐α and N‐1(τ) positions was achieved in four steps starting from L‐histidine methyl ester. Whereas, in the one‐step alternate route N‐α‐Boc‐L‐histidine methyl ester upon direct and simultaneous N‐α and N‐1(τ) alkylation with various alkyl halides in the presence of sodium hydride in DMF easily afforded N‐α,N‐1(τ)‐dialkyl‐L‐histidines 14 containing identical alkyl group at the N‐α and N‐1(τ) positions in high yields. Both procedures allowed facile entry to methyl and other higher alkyl groups at the N‐α‐position of the histidine ring