Selenium-sulfur analogs. 4. Synthesis and characterization of (±)-β-(2-amino-1,3-selenazol-4-yl)alanine

The novel amino acid (±)-β-(2-amino-1,3-selenazol-4-yl)alanine 4a was prepared from selenourea and 1,3-dichloropropan-2-one via a four-step synthetic sequence. Nuclear magnetic resonance analysis indicated a downfield chemical shift of δ 0.29 to 0.30 and δ 0.57 for the C₅-proton of the protonated 2-amino-and 2-acetamido-1,3-selenazoles respectively compared with the analogous thiazoles. The infrared spectra of the selenazole and corresponding thiazole compounds were virtually identical.