Crystal structures of the reaction product from ethyl acetoacetate and hydroxylamine, C8H8N2O3 • H2O, and its hexaaquamagnesium salt, Mg(H2O)62+(C8H7N2O2-)2 • 4H2O

The crystal structures of the two title compounds were determined by single crystal X-ray diffraction. The space group for the reaction product from the reaction between ethyl acetoacetate and hydroxylamine [3-methyl-4- (3-methylisoxazol-5-yl)isoxazol-5(2H)-one monohydrate] is P2(1)/c, No. 14, Z = 4. At 293 K a = 7.102(1), b = 13.113(2), c = 10.502(1) Angstrom, beta =107.180(8)degrees and V = 934.3(1) Angstrom(3). The space group for the hexaaquamagnesium salt [hexaaquamagnesium 3-methyl-4-(3-methylisoxazol-5-yl)-5-oxo-5H-isoxazol-2-ate tetrahydrate] is C2/m, No. 12, Z = 2. At 293 K a = 18.213(1), b = 6.8125(3), c = 10.8623(4) Angstrom beta =101.516(4)degrees, V = 1320.6 Angstrom(3). The structure of the isoxazolone compound previously determined from IR and UV spectra has been confirmed. The anion in the hexaaquamagnesium salt has a twisted conformation compared with the corresponding protonated form.