An Efficient One-Pot, Multicomponent Synthesis of 1, 3-Thiazolidin-4- Ones Using L-Proline as Catalyst in Water

Abstract

: An efficient methodology for the synthesis of 1,3-thiazolidin-4-ones using L-Proline as catalyst under aqueous conditions has been developed. The one-pot, multicomponent reaction of aromatic/heterocyclic aldehyde, aromatic amine and thioglycolic acid at room temperature give 1,3-thiazolidin-4-ones in moderate to good yields. Further, the current approach is notably greener than traditional methods with E-factor of 3.1 and the eco scale score of 96. The developed protocol offers several features, such as being simple, environmentally benign, energy-efficient, economical, mild conditions, shorter reaction time.

Multicomponent Synthesis of 4-Aryl-4,9-dihydro-1H-pyrazolo[3,4-b]quinolines Using L-Proline as a Catalyst—Does It Really Proceed?

“…In recent years, many multi-component reactions using L-proline as a catalyst have been mentioned for the synthesis of heterocyclic systems [14][15][16][17]. In 2017, Hegde and Shetty used aniline 5a, aromatic aldehyde 2/12, 2-phenyl-5-methyl-2,4-dihydro-3H-pyrazol-3-one 6b and L-proline as a catalyst in a reaction leading to pyrazolo [3,4-b]quinolines 13 (Scheme 4) [18].…”