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 C 5 ‐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.