[Synthesis]
The general procedure for the synthesis of 4-(2,4-dioxothiazolidin-5-ylmethyl)phenoxyacetic acid from the compound (CAS:172648-06-5) is as follows:
1. a methanol (0.65 L) solution of [4-[[2,4-dioxo-1,3-thiazolidin-5-yl]methyl]phenoxy]ethyl acetate (110 g, 0.36 mol) was mixed with a water (0.65 L) solution of Na2CO3 (200 g, 1.88 mol) at 0 °C and the reaction was stirred for 5 hours.
2. After completion of the reaction, methanol was removed by distillation under reduced pressure at 25~30 °C.
3. Water was added to the residue and acidified with hydrochloric acid.
4. The precipitated solid was filtered to afford the target product 4-(2,4-dioxothiazolin-5-ylmethyl)phenoxyacetic acid (80 g, 80% yield).
Product characterization: melting point 181-183 °C. 1H NMR (DMSO-d6) δ: 12.40 (bs, 1H, D2O exchangeable), 8.60 (bs, 1H, D2O exchangeable), 7.16 (d, J = 8.40 Hz, 2H), 6.50 (d, J = 8.40 Hz, 2H), 4.87 (dd, J = 9.14,4.20 Hz, 1H), 4.65 (s, 2H), 3.32 (dd, J = 14.12,4.20 Hz, 1H), 3.05 (dd, J = 14.12,9.14 Hz, 1H). |