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An Efficient Synthesis of 4(5)-Benzyl-L-Histidines Employing Catalytic Transfer Hydrogenolysis at Elevated Temperatures.

ABSTRACT: An efficient two-step synthesis of 4(5)-benzyl-L-histidine from L-histidine was developed. A Pictet-Spengler reaction between L-histidine and benzaldehyde in the presence of excess strong base yielded 4-phenylspinacine within one hour. Catalytic transfer hydrogenolysis in methanol at reflux using ammonium formate rapidly converted 4-L-phenylspinacine to 4(5)-benzyl-L-histidine within five minutes. No racemization of the final product 4(5)-benzyl-L-histidine was observed using the Marfey reagent. To show the utility of this methodology, a series of fluorinated benzylhistidines is presented.

SUBMITTER: Smith DD

PROVIDER: S-EPMC5663214 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature

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An Efficient Synthesis of 4(5)-Benzyl-L-Histidines Employing Catalytic Transfer Hydrogenolysis at Elevated Temperatures.

Smith D David DD Gallagher Audrey T AT Crowley Vincent M VM Gergens Wayne M WM Abel Peter W PW Hulce Martin M

Synthesis 20131210 4

An efficient two-step synthesis of 4(5)-benzyl-L-histidine from L-histidine was developed. A Pictet-Spengler reaction between L-histidine and benzaldehyde in the presence of excess strong base yielded 4-phenylspinacine within one hour. Catalytic transfer hydrogenolysis in methanol at reflux using ammonium formate rapidly converted 4-L-phenylspinacine to 4(5)-benzyl-L-histidine within five minutes. No racemization of the final product 4(5)-benzyl-L-histidine was observed using the Marfey reagent. ...[more]

PMID: 29097824

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