The synthesis of β‐heteroarylamino‐α,β‐dehydro‐α‐amino acid and β‐heteroarylamino‐α‐amino acid derivatives

From heteroarylaminomethyleneoxazolones 4 , obtained from N ‐heteroarylformamidines 2 and 2‐phenyl‐5‐oxo‐4,5‐dihydro‐1,3‐oxazole ( 3 ), the following β‐heteroarylamino‐α,β‐dehydro‐α‐amino acid derivatives were prepared: methyl 8 and ethyl esters 9 , amides 10 and 11 , hydrazides 12 , and azides 15 . By catalytic hydrogenation the compounds 4 were converted into β‐heteroarylamino substituted amides 18 and β‐heteroarylamino‐α‐amino acids 20 .