18572

Diammonium Hydrogen Phosphate: a Versatil and nexpensive Reagent for One-Pot Synthesis of Dihydropyrimidinones, Quinazolinones a d Azalactones under SolventFree Conditions

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Diarnmonium hydrogen phosphate, (N~hHP04, efficiently catalyzes the three-component Biginell i reaction between an aldehyde, a ~-dicarbonyl compound and urea or thiourea under solvent-free conditions to afford the corresponding dihydropyrimidinones in high yields. Also, the synthesis of 2,3-disu bsitituted-(3H)-quinazolin-4-ones is achieved by the one-pot reaction of isatoic anhydride, primary amines and orthoesters in the pre ence of ( N~hHP04 . The reaction of hippuric acid with aromatic aldehydes and acetic anhydride resulted in the formation of azal actones using catalytic amou nts of ( N ~)2H P04 י

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