Preparation and root growth-modulatory activity of N-substituted 2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanamides

N-Substituted 2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanamides (8) we re synthesized through the reaction of amines (13) with 2-acetylamino-2-eth oxycarbonyl-3-(2-furyl)propanoic acid (3b), which was prepared via condensa tion of 2-(bromomethyl)furan (10b) with diethyl acetamidomalonate, followed by partial hydrolysis of the resultant diethyl ester (3a) in the presence of barium hydroxide. However, bulky amines such as tert-butylamine or 2-tri fluoromethylaniline did not afford the corresponding diamides (8). The biological activity of the prepared diamides (8) as root growth modulat ors was examined by germination assay using rape and leek seeds. N-(5-Bromo -2-thiazoyl)- and N-(4-chloro-2-benzothiazolyl)-2-acetylamino-2-ethoxycarbo nyl-3-(2-furyl)propanamides (8h, i) both potently inhibited the root growth of rape seedlings, but were less effective in the case of leek seeds. The herbicide 2,4-dichlorophenolyacetic acid completely inhibited root growth i n both cases.