摘要 |
<p>Alpha amino acid derivatives (I), their optical isomers and addition salts, are new. Alpha amino acid derivatives of formula (I), their optical isomers and addition salts, are new: A = five-membered heterocycle, optionally substituted by a cyano group; Ak = 1-6C alkylene; X = single bond or phenylene; R1, R2, R4 = H or 1-6C alkyl; Y = NR4 or CH-NO2; R3 = NO2 or CN; and provided that: (i) when Y is CH-NO2, then R3 may further be 1-6C alkyl; and (ii) when A is unsubstituted, then Ak is propylene, X is a bond, Y is NH and R3 is NO2, are excluded.</p> |