One-Pot Synthesis of 5-Arylidene-2-Imino-4-Thiazolidinones under Microwave Irradiation

Abstract

A rapid and easy solvent free one-pot synthesis of 5-arylidene-2-imino-4-thiazolidinones by condensation of the thioureas with chloroacetic acid and an aldehyde under microwave-irradiation is described.

Three-Component, One-Flask Synthesis of Rhodanines (Thiazolidinones)

“…25–27 A new transformation of multifunctional enoate esters 2 , occurring in 2-propanol solvent under mild (25 °C) conditions, produces various 5-alkylidene rhodanine derivatives typically favoring Z over E olefins by 30:1 to 7:1 ratios; routine silica gel column chromatography afforded the pure 5-( Z )-alkylidene rhodanines in the yields shown in Scheme 1. The (Z) -geometry of the 5-alkylidene rhodanines 3 – 5 is consistent with literature analogies 28–31 and was confirmed by 1 H NMR spectroscopy. The 1 H NMR spectra of the crude reaction mixtures contained two distinct triplets for the single olefinic proton, the major triplet at 6.98–7.02 ppm and the minor triplet at 6.47–6.52 ppm.…”

“…These 1 H NMR data are consistent with the Z -isomer olefinic proton being further downfield then the E -isomer olefinic proton, because of deshielding from the carbonyl group. 28–31 …”

A facile, rapid, one-pot regio/stereoselective synthesis of 2-iminothiazolidin-4-ones under solvent/scavenger-free conditions

“…A common strategy involved in the prevailing synthetic protocols for 2-iminothiazolidin-4-ones [12–14] is the cyclization of thioureas with α-halocarboxylic acids [15] or acyl halides [16–17] or carboxylic esters [18]. These protocols are generally solution phase methods using organic solvents and acid scavengers.…”

Microwave-assisted synthesis and in-vitro anti-tumor activity of 1,3,4-triaryl-5-N-arylpyrazole-carboxamides

“…Chemistry 5-Arylidene-2-imino-4-thiazolidinones 3a, 3c and 3d have been synthesized by the conventional heating of 2-imino-4-thiazolidinones 2 with the appropriate aldehyde under basic or acidic conditions [31,32]. Recently, compound 3a was prepared by a onepot three component solvent-free reaction of N,N-diphenylthiourea 1a with chloroacetic acid and benzaldehyde under microwave irradiation [33]. In this study, we synthesized compounds 3aed according to the latter reported procedure and their Z configuration was assigned as shown in Scheme 1 [34e38].…”