A One-pot Multi-component Synthesis of Dihydropyrimidinone/Thione and Dihydropyridine Derivatives via Biginelli and Hantzsch Condensations using t-BuOK as a Catalyst Under Solvent-free Conditions

Abstract

Abstract:The synthesis of various substituted Biginelli 3,4-dihydropyrimidinone/thione and Hantzsch 1,4-dihydropyridine derivatives has been achieved using a modified procedure in the presence of potassium ter-butoxide (tBuOK) as a catalyst under solvent-free conditions, in good to excellent yields.

Organocatalyzed Biginelli Reactions

“…Tetrabutylammonium bromide was also demonstrated to act as a catalyst in a Biginelli reaction [56]. Debache and collaborators (2012) demonstrated the catalytic properties of potassium tert-butoxide (CAT-45) in the Biginelli reaction [57]. The Biginelli adducts were obtained under these conditions in yields higher than 90% (Table 8).…”

A Green Approach for the Synthesis of 2,4-Dihydro-pyrimidinones Using PTSA

“…Several methods improved the procedure using phosphorus pentoxide-methanesulfonic acid 4 , potassium ter-butoxide (t-BuOK) 5 , ammonium dihydrogen phosphate 6 , silica-gel 7 , mesoporous molecular sieve MCM-41 8 , cyanuric chloride 9,10 , nano-BF 3 ⋅SiO 2 silica gel supported polyphosphoric acid 11 , zirconium(IV) chloride 12 , and indium(III) bromide 13 14 have been employed for this transformation.…”

One-Pot Synthesis of Substituted Piperidinones and 3,4-Dihydropyrimidinones Using a Highly Active and Recyclable Supported Ionic Liquid Phase Organocatalyst

“…3,4-Dihydropyrimidinones have also been reported to posses diverse pharmacological properties such as anti-viral, anti-bacterial, and anti-hypertensive properties, as well as efficacy as calcium channel modulators and 1a-antagonist. [22] Numerous methods are available in the literature on the synthesis of DHPMs, [23][24][25] which includes certain drawbacks, such as the use of harsh reaction conditions and expensive and toxic catalysts, and long reaction times, low yields, and tedious workup procedures.…”