Table 1.

Synthesis of dihydropyrimidone(thione)s 152–156 of antiproliferative interest mediated by Biginelli type three-component reactions.

Reagents			Conditions	Product	Reference
type 8	RCHO type 1	6	p-sulfonic acid calix[4]arene (0.5% mol), EtOH, reflux	152 a	[169]
type 27	type 1		p-sulfonic acid, EtOH, reflux	153 b	[169]
type 27	ArCHO/R2CHO 1		MAI·Fe2Cl7 (5 mol%), BMI·BF4 IL (1 mL), 80 °C	154 c	[170]
			Heterogeneous Zn- and Cd-based CPs catalysts (5 mol%), 70–100 °C, Continuous flow	155 d	[171]
type 27		type 6	Bi(NO3)3.5H2O, 70 °C, solvent free	156 e	[172]

^a For compounds 152: X = O, S; R = 3-HOC₆H₄, Ph, 4-HOC₆H₄, 3,4-(HO)₂C₆H₃, 4-MeOC₆H₄, 3-MeOC₆H₄, 4-HO-3-MeOC₆H₃, 4-HO-3,5-(MeO)₂C₆H₂, 4-MeSC₆H₄, 3,4-(OCH₂O)C₆H₃, 4-FC₆H₄, Pr, cyclohexyl. ^b For compounds 153: X = O, S; R = OEt, PhNH, 4-MeC₆H₄NH, 4-MeOC₆H₄NH, 4-ClC₆H₄NH, 2-ClC₆H₄NH, 4-NO₂C₆H₄NH; R¹ = H, Cl. ^c For compounds 154: X = O, S; R = OEt, Me; R¹ = Me; R² = Ph, 4-ClC₆H₄, 3-HOC₆H₄, 2-HOC₆H₄, 3-NO₂C₆H₄, 2-NO₂C₆H₄, 4-HO-3-MeOC₆H₃, H, Me, 2-furyl, 3,4-(OCH₂O)C₆H₃. ^d For compounds 155: X = O, S; R = OEt; R¹ = Me; Ar = Ph, 3-HOC₆H₄, 3-NO₂C₆H₄, 4-HO-3-MeOC₆H₃, 3,4-(OCH₂O)C₆H₃. ^e For compounds 156: R = OMe, OEt, Me; Ar = Ph, 4-MeOC₆H₄, 4-MeC₆H₄, 4-NO₂C₆H₄, 2,4-(Cl)₂C₆H₃, 2,3-(Cl)₂C₆H₃, 2,3-(F)₂C₆H₃, 2-furyl.