1.
Synthesis (Stuttg)
; 46(4): 515-521, 2014 Feb.
Article
in English
| MEDLINE
| ID: mdl-29097824
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.