Chloro(trimethyl)silane-catalyzed three-component condensation of diethyl 3,3′-(1,3-phenylene)bis(3-oxo-propanoate) with aromatic aldehyde and urea. New synthesis of diethyl 4,4′-(1,3-phenylene)bis(2-oxo-1,2,3,6-tetrahydropyrimidine-5-carboxylates)

Acid Catalyzed One‐pot Three‐component Biginelli‐type Synthesis of Some New Symmetrical Bis 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones

“…However, so far, the synthesis of mono 3,4‐dihydropyrimidones has been taken into considerable interest while the synthesis of Biginelli compounds, containing two dihydropyrimidinone units, have been less studied and reported. We have found few publications in which the use of bis reagents, that is, these have two similar functional groups necessary for the Biginelli reaction has been described . Improved conditions have been found to carry out the Biginelli reaction for the synthesis of bis dihydropyrimidones 1 and 2 in very good yields.…”

“…Benzene bridged bis dihydropyrimidinones 4 were performed with compounds having two β‐keto ester moieties (for building up two pyrimidine rings) in a single molecule (Fig. ) .…”