Magnesium Bromide and Magnesium Chloride Hexahydrate Catalyzed One‐Pot Synthesis of Dihydropyrimidines viaBiginelli Reaction under Solvent‐Free Conditions

Abstract

Biologically important 12 new important 3,4‐dihydropyrimidin‐2‐(1H)‐ones (‐thiones) were synthesized with in one‐pot three‐component Biginelli reaction from the corresponding aromatic aldehydes (5‐methyl‐2‐thiophenecarboxaldehyde and 2‐chloro‐5‐nitrobenzaldehyde), β‐keto esters (ethylacetoacetate, allylacetoacetate, and t‐butylacetoacetate), and urea/thiourea in the presence of catalytic amount of magnesium bromide and magnesium chloride hexahydrate as nontoxic, inexpensive, and easily available catalysts under solvent‐free conditions at 80 and 100°C. Compared with the catalyst‐free three‐component Biginelli reaction conditions, this method consistently has the advantage of short reaction time (45–100 min) and good to excellent yields (75–91%).

Acid Catalyzed One‐pot Three‐component Biginelli‐type Synthesis of Some New Symmetrical Bis 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones

“…In the continuation of our studies on the synthesis of dihydropyrimidinone derivatives by using catalyst , herein we wish to report the synthesis of new symmetrical bis 3,4‐dihydropyrimidin‐2‐(1 H )‐ones/thiones 13a – i and 14a – l in the presence of p‐TSA·H 2 O or conc. HCl (Scheme ).…”

Yeşil Kimya Ölçümleri: Katalizörlü ve Katalizörsüz Reaksiyon Şartlarında Sentezlenmiş Biginelli Bileşiklerinin Yeşil Kimya Ölçümlerinin Hesaplanması

“…Bu çalışmada, daha önceki bir araştırmamızda MgBr2, MgCl2•6H2O katalizörlü ve katalizörsüz olarak, aromatik aldehit (5-metil-2-tiyofenkarbaldehit ve 2-kloro-5nitrobenzaldehit), β-keto ester (etilasetoasetat, allilasetoasetat, tbütilasetoasetat) ve üre/tiyoüre ile sentezlenen ve biyolojik aktivitesi henüz araştırılmamış olan oniki adet 3,4dihidropirimidin-2-(1H)-on/tiyon türevlerinden (Gülten, 2013) elde edilen veriler yardımıyla yeşil kimya ölçümleri hesaplanmıştır.…”

“…Bu moleküllerin katalizörlü ve katalizörsüz reaksiyon şartlarında sentez yöntemleri aşağıda verildiği şekilde uygulanmıştır (Figure 3) (Gülten, 2013).…”

Heterogeneous catalysts NiCoSe2 and NiCo2S4 for the effective synthesis of dihydropyrimidine-2-ones/thiones

“…The Biginelli reaction was catalyzed by using different homogenous metal catalysts such as ZnCl 2 , 16 MgCl 2 , 17 CaCl 2 , 18 and SrCl 2 . 19 Although significant progress has been made in the research on the Biginelli reaction, there are still several challenges that need to be addressed.…”