Biginelli, Pietro

In 1893 Pietro Biginelli reported the first synthesis of 4-aryl-3,4-dihydropyrimidin-2(l//)-ones (DHPMs) via an one-pot process using three components. Thus, DHPM 7 was synthesized by mixing benzaldehyde (5), ethyl acetoacetate (6), and urea (3a) in ethanol at reflux in the presence of a catalytic amount of HCl. 

Biginelli, P. Ber. Dtsch. Chem. Ges. 1891, 24, 1317. Pietro Biginelli was at Lab. chim. della Sanita pubbl. Roma, Italy. 

In 1893, the Italian chemist Pietro Biginelli (University of Florence) for the first time reported on the acid-catalyzed cyclocondensation reaction of ethyl acetoacetate 1, benzaldehyde 2, and urea 3 [1], The reaction was carried out by simply heating a mixture of the three components dissolved in ethanol with a catalytic amount of HC1 at reflux temperature. The product of this novel one-pot, three-component synthesis that precipitated on cooling the reaction mixture was identified as 3,4-dihydropyrimidin-2(lH)-one 4 (Scheme 4.1) [2]. This reaction is nowadays referred to as the Biginelli reaction , Biginelli condensation or as the Biginelli dihydropyrimidine synthesis . 

In 1893 the Italian chemist Pietro Biginelli [2] reported the one-pot synthesis of 4-aryl-3, 4-dihydropyrimidin-2(lff)-ones (DHPMs 1) by a three-component condensation reaction of aromatic aldehydes, urea and ethylacetoacetate (Scheme 11.1). 

In 1893, Pietro Biginelli published his pioneering findings on a threereaction that has become known as the Biginelli reaction. This three-component one-pot reaction leads to the synthesis of dihydropyrimidines (130), typically via the reaction of a benzaldehyde (131), an acetoacetate (132), and a (thio)urea (133) under acid catalysis [73]. The Biginelli reaction is quite versatile since it can be performed with variations in all three components, leading therefore to a myriad of dihydropyrimidines (Scheme 3.33). 

The Passerini reaction followed the reaction of Pietro Biginelli (1860-1937) who, in 1891, proposed the revolutionary idea of a multi-component reaction [5-8]. 

In 1893,11 years after the publication of the Hantzsch dihydropyridine synthesis, the Italian chemist Pietro Biginelli reported a related three-component reaction based on the cyclocondensation of aldehydes, p-ketoesters, and urea, for the synthesis of... 

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