Synthetic of α-Methylhistidine by Catalytic Phase-Transfer Alkylations

Abstract
α-Methylhistidine was prepared by two complementary routes using a catalytic phase-transfer alkylation procedure. Construction of the product was achieved either by alkylation of an alanine Schiff base ester with an imidazole-containing electrophile or by methylation of a protected histidine derivative. Hydrolysis of the protecting groups afforded α-MeHis·2HCl in 27–41% overall yield.