DOI: 10.1002/cssc.201200524 Catalytic Synthesis of Hydroxymethyl-2-oxazolidinones from Glycerol or Glycerol Carbonate and Urea Angela Dibenedetto,* [a] Francesco Nocito, [a] Antonella Angelini, [a] Imre Papai, [b] Michele Aresta, [c] and Raffaella Mancuso [d] Introduction 2-Oxazolidinones are important heterocyclic compounds that find applications in several fields of the pharmaceutical and chemical industry. In particular, they have long been used as antibiotics [1] or pesticides [2] and in drug [3] and fiber produc- tion. [4] In recent years, polymers containing 2-oxazolidinones have been developed for applications as foams, adhesives, and fibers. [5] Industrially, 2-oxazolidinones are synthesized by phosgena- tion of the corresponding 1,2-amino alcohols [6, 7] (Scheme 1a); this is a non-ecofriendly route that calls for alternatives. Only a few greener synthetic procedures have been pro- posed that avoid the use of toxic phosgene, including the re- action of 1,2-amino alcohols with CO 2 [8] (Scheme 1b) or CO/ O 2 [9] (Scheme 1c). Alternatively, 2-oxazolidinones can be syn- thesized from aziridines and carbon dioxide [10] or by treating cyclic carbonates with 1,2-amino alcohol. [11–13] All such routes are affected by drawbacks such as 1) the formation of poly- mers that generate a low yield of the target product, 2) unfav- orable reaction conditions (high pressure, high temperature), and 3) high costs. Herein, we report the synthesis of hydroxymethyl-2-oxazoli- dinones by reacting glycerol carbonate and urea (Scheme 2) or Oxazolidinones have been synthesized by reacting glycerol car- bonate or glycerol with urea in the presence of g-Zr phosphate as a catalyst. The conversion yield of the polyol or its carbon- ate 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 selec- tivity decreases, which makes the separation process more dif- ficult. 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 pre- ferred: the ratio of 6’/6 is close to 7. The oxazolidinones formed act as templates because they interact through hydro- gen bonding with glycerol. The intensity of the interaction de- pends on the 6 or 6’ isomer: DFT calculations showed that the energy was 22.6 kcal mol À1 for 6-oxazolidinone and 25.7 kcal mol À1 for 6’-oxazolidinone. Scheme 1. The “phosgene-based” route (a) to the synthesis of 2-oxazolidi- none and two alternative “phosgene-free” routes (b and c). Scheme 2. Route for the synthesis of 2-oxazolidinones from glycerol carbon- ate. [a] Prof. A. Dibenedetto, Dr. F. Nocito, Dr. A. Angelini Department of Chemistry and CIRCC University of Bari, Campus Universitario via Orabona 4, 70126 Bari (Italy) Fax: (+ 39) 080-5443606 E-mail : a.dibenedetto@chimica.uniba.it [b] Dr. I. Papai CIRCC, University of Bari Via Celso Ulpiani 27, 70126 Bari (Italy) [c] Prof. M. Aresta Chemical Research Center Hungarian Academy of Sciences 1525 Budapest, P.O.B. 17 (Hungary) [d] Dr. R. Mancuso Dipartimento di Chimica Università della Calabria 87036 Arcavacata di Rende (CS) (Italy)  2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim ChemSusChem 2013, 6, 345 – 352 345 CHEMSUSCHEM FULL PAPERS