Preparation of Derivatives of 2-Cyano-3-(5- N -arylamino- or 5- N -Alkyl- N -phenylamino-2-furyl)propenoic Acids
(5-Bromo-2-furyl)methylidenemalonodinitrile (1) reacted with substituted aromatic amines under formation of (5-N-arylamino-2-furyl)methylidenemalonodinitriles 2a-2h whereas no reaction was observed with N-alkyl-N-phenylamines. Derivatives of 2-cyano-3-(5-N-alkyl-N-phenylamino-2-furyl)- propenoic acid 5a-5o were prepared by reaction of the corresponding N-alkylanilines with 5-bromo-2-furancarbaldehyde, followed by hydrolysis of the obtained Eiji salts and reaction with malonic acid derivatives.