Reaction Conditions For Esterification Research Articles

Poly(ethylene-<I>co</I>-vinyl alcohol) Functionalized Single-Walled Carbon Nanotubes and Related Nanocomposites

Single-walled carbon nanotubes (SWNTs) were functionalized by poly(ethylene-co-vinyl alcohol) (EVOH) copolymer under carbodiimide-activated esterification reaction conditions. Similar to the parent EVOH copolymer, the EVOH-functionalized carbon nanotubes are soluble in highly polar solvent systems such as DMSO and hot ethanol-water mixtures. The soluble EVOH-SWNT sample was characterized by various techniques, including optical absorption, Raman, NMR, electron microscopy, and thermogravimetric analysis. The common solubility of EVOH and EVOH-SWNT allowed their intimate mixing in solution, and thus the fabrication of nanocomposites in which the SWNTs are homogeneously dispersed in the polymer matrix.

Novel Isothiocyanato Esters Appended to Task-Specific Ionic Liquid as New Tools For Ionic Liquid Phase Organic Synthesis (IoLiPOS)

The synthesis of isothiocyanato esters appended to (polyethylene glycol)-ionic liquid phases is reported. The starting task-specific ionic liquids (TSILs) were functionalized in good yields with bromoacetic acid or 4-chlorobutyroyl chloride by usual esterification reaction conditions. In the second step, the isocyanato esters appended to TSILs were obtained by displacement with potassium thiocyanate in refluxing anhydrous MeCN. The isothiocyanato-TSILs were characterized by NMR (1H, 13C), mass spectrometry (MS) and IR spectroscopy.

Efficient combination of task-specific ionic liquid and microwave dielectric heating applied to one-pot three component synthesis of a small library of 4-thiazolidinones

The first report of the use of task-specific ionic liquid as synthetic equivalent of ionic liquid-phase matrice for the preparation of a small library of 4-thiazolidinones is reported in this paper. The starting (ethyleneglycol)ionic liquid-phase is functionalized in good yields with 4-(formylphenoxy)butyric acid by using usual esterification reaction conditions (DCC/DMAP as catalyst). The synthesis of the ionic liquid-phase bound 4-thiazolidinones was performed by a one-pot three-component condensation under microwave dielectric heating. The final cleavage under microwave/catalysis strategy provides the expected 4-thiazolidinones in high purity after flash-chromatography purification. According to the ionic liquid-phase organic synthesis (IoLiPOS) methodology, it was found that optimized reaction conditions were performed by standard analytical methods (NMR, TLC). The 1H, 13C NMR spectrum of some representative 4-thiazolidinones and ionic liquid-phase bound benzaldehyde are also reported.