title: Catalytic synthesis of hydroxymethyl-2-oxazolidinones from glycerol or glycerol carbonate and urea.
abstract: Oxazolidinones have been synthesized by reacting glycerol carbonate or glycerol with urea in the presence of γ-Zr phosphate as a catalyst. The conversion yield of the polyol or its carbonate depends on the temperature. Below 408 K the selectivity is 100 % with a conversion of up to 25 %, whereas increasing the temperature means that conversion yield grows, but the selectivity decreases, which makes the separation process more difficult. Starting from glycerol carbonate, two isomers, 6 and 6', are formed with a quasi 1:1 molar ratio because urea can attack the carbonate moiety on both sides of the carboxylic CO moiety. From glycerol the formation of the 6' isomer is preferred: the ratio of 6'/6 is close to 7. The oxazolidinones formed act as templates because they interact through hydrogen bonding with glycerol. The intensity of the interaction depends on the 6 or 6' isomer: DFT calculations showed that the energy was 22.6 kcal mol(-1) for 6-oxazolidinone and 25.7 kcal mol(-1) for 6'-oxazolidinone.
authors.affiliation: Department of Chemistry and CIRCC, University of Bari, Campus Universitario, via Orabona 4, 70126 Bari, Italy. a.dibenedetto@chimica.uniba.it
authors.forename: Angela
authors.initials: A
authors.lastname: Dibenedetto
authors.forename: Francesco
authors.initials: F
authors.lastname: Nocito
authors.forename: Antonella
authors.initials: A
authors.lastname: Angelini
authors.forename: Imre
authors.initials: I
authors.lastname: Papai
authors.forename: Michele
authors.initials: M
authors.lastname: Aresta
authors.forename: Raffaella
authors.initials: R
authors.lastname: Mancuso
mesh_terms: D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D005990:Glycerol / Q000031:analogs & derivatives* / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D023303:Oxazolidinones / Q000138:chemical synthesis* / Q000737:chemistry*; D013696:Temperature; D014508:Urea / Q000737:chemistry*
chemical_list: D023303:Oxazolidinones; D014508:Urea; D005990:Glycerol