Multicomponent synthesis of dihydropyrimidones (DHPMs) from furfural derivatives catalyzed by H14NaP5W29MoO110@SiO2

G. ROMANELLI; O. PORTILLA; E. NOPE; A. SATHICQ; V. PALERMO

Congreso; 46 IUPAC World Chemistry Congress; 2017

Furfural is universally made from biomass rich in pentosan; by acid hydrolysis and dehydration of generated pentose [1]. This aldehyde can be used like starting material for dihydropyrimidones (DHPMs) synthesis. Dihydropyrimidones have interesting biological activities, such as antibacterial, antiflammatory, antiviral and calcium channel modulating activity [2]. Inside of the dihydropyrimidones synthesis stand out the Biginelli method; the condensation of aldehyde, -ketoester and urea related compounds because provides an easy access to the preparation of DHPMs. The Biginelli reaction is one example of multicomponent reaction (MCR). The MCR methodologies offer significant advantages over conventional linear-type synthesis. Some of the highlights are speed, atomic efficiency [3], one step reaction and the diminution of purification steps to yield the products. The original Biginelli process used HCl like catalyst, however, if compare heteropolyacids like H14NaP5W29MoO110 (named Preyssler acid) is not corrosive, inexpensive, reusable and environment ? friendly [4]. In this work, we developed and optimized the DHPMs synthesis from furfural derivatives using H14NaP5W29MoO110@SiO2 like reusable catalyst. H14NaP5W29MoO110@SiO2 catalyst was synthetized using the sol-gel technique from the Preyssler acid obtained by the classic method [5]. The Biginelli reaction was developed at 80oC in a solvent free media for 6 or 8 hours. The yields for the DHPMs are between 48 and 93% (table 1). DHPMs from thiourea have a complex purification steps while nitrofurfural derivatives crystallized easily. All obtained products are being characterized by UV-Vis, IR, 1H and 13C RMN and physical properties (solubility and melting point).