Synthesis of Unnatural α-Amino Acids and Heterocycles as New Bases of Nucleoside Moiety

Abstract

The treatment of 4-(3,4-Dichlorophenyl)-4-oxobut-2-enoic acid with ethylglycinate, anthranilic, and phenylene diamine, can be afforded butanoic acid derivatives 1 as unnatural α-amino acid. The aza-Michael adducts 1 are used as a key starting materials to synthesize some heterocycles include furanone, benzoxazapindione, pyridazinone and quinoxaline deriva- tives via treatment of the adducts 1 with electrophilic and nucleophilic reagents to synthesize new bases of nucleoside moieties. The acid chloride of dibasic adduct 1b can be afforded regioselective heterocycles indolone 9, and quinolone 10 depending on pH medium.