T. Kitagawa et al., Preparation and root growth-modulatory activity of N-substituted 2-acetylamino-2-ethoxycarbonyl-3-(2-furyl)propanamides, CHEM PHARM, 49(3), 2001, pp. 335-339
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.