FeCl3 catalysed two consecutive aminomethylation at the α-position of the β-dicarbonyl compounds: an easy access to hexahydropyrimidines and its spiro analogues

Facile and efficient synthesis of 4'-thioxo-1',3,3',4,4',6' -hexahydro-1H,2'H-spiro[naphthalene-2,5'-pyrimidin]-1-ones in a three-component Mannich-type reaction

“…Furthermore, in comparison with similar reactions of ketones 19,27 the molar ratio of reagents is much different, in our case. In the preparative procedures both the amine and formaldehyde were used in an excess in order to optimize the yield of the hexahydropyrimidines.…”

“…27 Six molecules of reactants were involved and six new covalent bonds were formed in this one-pot three-component reaction; the highest yields of hexahydropyrimidines were obtained when the 1,3-carbonyl compound : amine : formaldehyde molar ratio was 1 : 2 : 3. An analogous reaction course was reported in the case of the proline-catalyzed aminomethylation of cyclohexanone.…”

“…Mukhopadhyay and co-workers 27 reported a multicomponent synthesis of 1,3-diarylhexahydropyrimidines in the one-pot reaction of 1,3-dicarbonyl compounds, aromatic amines and formaldehyde catalyzed by iron(III) chloride. T. B. Shah and co-workers 28 described their results of the synthesis and in vitro biological screening of a series of N-Mannich bases obtained from 3,4-dihydropyrimidine-2-(1H)-thiones; those with morpholine as the heterocyclic secondary amino component showed a promising activity against both bacterial and fungal microorganisms.…”

Synthesis of sulfanylidene-diazaspirocycloalkanones in a three-component Mannich-type reaction catalyzed with lactic acid

“…In the earlier studies of the three-component reactions of amines and formaldehyde with β-diketones, β-keto esters 9 or cyclohexanone, 11,20 double aminomethylation was observed to occur at the -carbon atom. Six molecules of reactants were involved and six new covalent bonds were formed in this one-pot, threecomponent reaction.…”

“…Thus, Mukhopadhyay and co-workers reported a multicomponent synthesis of 1,3-diarylhexahydropyrimidines in the one-pot iron(III) chloride-catalyzed reaction of 1,3-dicarbonyl compounds, aromatic amines and formaldehyde. 9 Liang and co-workers lately synthesized 1,3-diaryl-5-spirohexahydropyrimidines via the proline-catalyzed one-pot condensation of anilines, formaldehyde, and cyclohexanones. 10 Dandia and co-workers obtained several fluorine-containing spirohexahydropyrimidine derivatives using the magnetically separable and easy recyclable heterogeneous CuFe2O4 nanocatalyst, 11 while Zeba and co-workers used a chitosan supported Dy(III) catalyst for the fairly green and energy-sustainable synthesis of hexahydropyrimidine derivatives.…”