
Keggin heteropolyacid-based catalysts for the preparation of substituted ethyl β-arylaminocrotonates, intermediates in the synthesis of 4-quinolones
Keywords: Keggin HPA; SiMCM-41; Amine-SiMCM-41; Catalysts; Conrad–Limpach reaction; Substituted anilines; Ethyl acetoacetate; Ethyl β-arylaminocrotonates