Reaction Steps
Potassium phosphate tribasic (6.6 g, 31 mmol), 4-iodo-1H-pyrazole (2.0 g, 10 mmol), and 5-(chloromethyl)oxazolidin-2-one (2.8 g, 21 mmol) were suspended in dioxane (0.10 L, 0.10 M). The reaction vessel was heated to 110° C. for 48 hours, then cooled to room temperature and diluted with dichloromethane (0.25 L). The organics were washed with H2O (2×0.20 L) and were concentrated under reduced pressure. The residue was suspended in methanol:hexanes for 3 hours at ambient temperature with stirring. The precipitate was filtered to afford 5-((4-iodo-1H-pyrazol-1-yl)methyl)oxazolidin-2-one. MS ESI calcd. for C7H9IN3O2 [M+H]+ 294. found 294. 1H NMR (500 MHz, DMSO-d6) δ 7.90 (s, 1H), 7.56 (s, 1H), 7.54 (s, 1H), 4.94-4.77 (m, 1H), 4.42-4.32 (m, 2H), 3.54 (t, J=9.0, 1H), 3.24 (dd, J=6.4, 8.8, 1H). The racemic compound, thus obtained, was resolved by chiral super critical fluid chromatography (IC column, 1:4 Isopropanol/CO2) to afford (R or S) 5-((4-iodo-1H-pyrazol-1-yl)methyl)oxazolidin-2-one (early eluting enantiomer): MS ESI calcd. for C7H9IN3O2 [M+H]+ 294. found 294. 1H NMR (500 MHz, DMSO-d6) δ 7.90 (s, 1H), 7.56 (s, 1H), 7.54 (s, 1H), 4.94-4.77 (m, 1H), 4.42-4.32 (m, 2H), 3.54 (t, J=9.0, 1H), 3.24 (dd, J=6.4, 8.8, 1H); and (R or S) 5-((4-iodo-1H-pyrazol-1-yl)methyl)oxazolidin-2-one (late eluting enantiomer), MS ESI calcd. for C7H9IN3O2 [M+H]+ 294. found 294. 1H NMR (500 MHz, DMSO-d6) δ 7.90 (s, 1H), 7.56 (s, 1H), 7.54 (s, 1H), 4.94-4.77 (m, 1H), 4.42-4.32 (m, 2H), 3.54 (t, J=9.0, 1H), 3.24 (dd, J=6.4, 8.8, 1H).
