Greener approach for the synthesis of substituted alkenes by direct coupling of alcohols with styrenes using recyclable Bronsted acidic [NMP]+HSO4− ionic liquid

A green protocol for the synthesis of substituted alkenes from alcohols and styrenes using recyclable [NMP]⁺HSO₄⁻ ionic liquid catalyst with higher atom efficiency has been developed.

1-Methylimidazolium hydrogen sulfate catalyzed convenient synthesis of 2,5-dimethyl-N-substituted pyrroles under ultrasonic irradiation

Ionic liquid [HMIM]HSO4 was found to be an efficient catalyst for the synthesis of N-substituted pyrroles through the reaction of 2,5-hexanedione with amines under ultrasonic irradiation at room temperature. These reactions proceed with good yields under short reaction time. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.

Ionic liquid under ultrasonic irradiation towards a facile synthesis of pyrazolone derivatives

Ionic liquid [HMIM]HSO(4) was found to be an efficient catalyst for the synthesis of 4-[(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-phenyl-methyl]-5-methyl-2-phen-yl-1,2-dihydro-pyrazol-3-ones through the condensation reaction of arylaldehydes and 3-methyl-1-phenyl-5-pyrazolone under ultrasonic irradiation at room temperature. The present methodology offers several advantages such as excellent yields, simple procedure and mild conditions.