One-pot synthesis of ferrocenyl-pyrimidones using a recyclable molibdosilicic H4SiMo12O40 heteropolyacid

P. VAZQUEZ; N. NOLTE; J. JIOS; G. ROMANELLI

RESEARCH ON CHEMICAL INTERMEDIATES

SPRINGER

Lugar: Berlin; Año: 2016 vol. 42 p. 977 - 986

0922-6168

A series of ferrocene-containing dihydropyrimidines (DHPs) were preparedby the one-pot Biginelli reaction of formylferrocene, 1,3-dicarbonyl componentand urea/thiourea. The reaction was catalyzed by a commercial Kegginheteropolyacid (H4SiMo12O40) as a safe, clean and recyclable catalyst. Three different synthetic protocols were examined in order to improve the yields of thereaction and to elucidate its mechanism. Intermediates of the competitive Knoevenagel reaction were also isolated. The methodology is operationally simple and provides access to highly substituted dihydropyrimidines containing ferrocene in very good yields. The catalyst can be used and recycled without appreciable loss of the catalytic activity.