In 1998, Paolo Strazzolini and others synthesized this compound by reacting oxalyl chloride (COCl)2 or the bromide (COBr)2 with a suspension of silver oxalate (Ag2C2O4) in diethyl ether at −15 °C, followed by evaporation of the solvent at low temperature and pressure. The substance is stable when dissolved in ether and trichloromethane at −30 °C, but decomposes into a 1:1 mixture of carbon monoxide (CO) and carbon dioxide (CO2) upon heating to 0 °C. The stability and conformation of the molecule were also analyzed by theoretical methods.
^Strazzolini, P.; Gambi, A.; Giumanini, A. G.; Vancik, H. (1998). "The reaction between ethanedioyl (oxalyl) dihalides and Ag2C2O4: a route to Staudinger’s elusive ethanedioic (oxalic) acid anhydride". Journal of the Chemical Society, Perkin Transactions 11998 (16): 2553–2558. doi:10.1039/a803430c.
^Gambi, A.; Guimanini, A. G.; Strazzolini, P. (2001). "Theoretical investigations on (CO)n(CO2)m cyclic cooligomers". Journal of Molecular Structure: THEOCHEM536 (1): 9–16. doi:10.1016/S0166-1280(00)00601-1.