A Highly Efficient Tandem Knoevenagel/Michael Reaction Using Mohr’s Salt Hexahydrate as a Green and Powerful Catalyst: Selective Synthesis of Benzylpyrazolocoumarins on Water

Abstract

In this work, new, efficient, and environmentally adapted synthesis of benzylpyrazolocoumarins in one‐pot is introduced. From tri‐component reaction of a wide range of aryl aldehydes, 4‐hydroxycoumarin, and 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one on water, benzylpyrazolocoumarins with good to excellent yields in a green procedure were synthesized. The highly efficient role of ferrous ammonium sulfate hexahydrate (Mohr’s salt) as a new green catalyst in this synthesis is obviously demonstrated. This novel procedure is an effective, cheap and environmentally adapted route to the synthesis of benzylpyrazolocoumarin derivatives. The crude products recrystallized to afford the crystalline pure product. This novel procedure has some advantages such as high efficiency, simplicity, high rate and environmental safety.

Rapid and Efficient Uncatalyzed Knoevenagel Condensations from Binary Mixture of Ethanol and Water

“…The reactions with heteroaromatic aldehydes (entries 20,22) finished in a short time. As the n-pyridinecarboxyaldehydes (n = 3 or 4, entries 20, 21) are rather reactive electrophiles and are completely miscible in water, the reactions with these substrates were incredibly fast (in seconds).…”

“…In the earliest works, the amines used to catalyze the reactions presented a considerable level of toxicity. 16,17 Thus, many papers have been published in recent years concerning proposals for ecofriendly reaction conditions, [18][19][20][21][22] in accordance with the principles of green chemistry. [22][23][24][25] From this perspective, many researchers have developed new catalysts involving the mentioned principles.…”

Unraveling the Anticancer Potential of Cinnamonitrile Derivatives: In vitro Evaluation and Molecular Docking

“…This transformative chemical reaction culminates in the creation of α,β‐unsaturated compounds through condensing carbonyl‐bearing compounds with those possessing activated methylene [4,5] . The Knoevenagel reaction has lent its prowess to myriad studies, facilitating the synthesis of a diverse array of organic compounds, many of which exhibit compelling biological activities [6–9] …”

“…[4,5] The Knoevenagel reaction has lent its prowess to myriad studies, facilitating the synthesis of a diverse array of organic compounds, many of which exhibit compelling biological activities. [6][7][8][9] The profound biological potential of α,β-unsaturated compounds has cast them as captivating molecules, beckoning the interest of chemists and pharmacologists. These compounds have showcased an extensive and diverse spectrum of biological activities, spanning anti-nociception through TREK-1 channel modulation, [10,11] inhibition of 12-Lipoxygenase, [12] acaricidal-fungicidal attributes, [13] antagonism of NMDA receptors, [14] and therapeutic potential for circulatory system diseases.…”