反应详情

To a slurry of 2-[4'-(amino)thiophenoxy]-3-hydroxymaleic acid (0.370 g, 1.438 mmol) and freshly powdered, freshly dried K2CO3 (1.217 g, 8.806 mmol in THF (30 mL) under nitrogen was added thiophosgene (0.33 mL, 0.498 g, 4.33 mmol). The reaction mixture was stirred vigorously at room temperature for 1 hour, then at reflux for 30 minutes. Upon cooling to room temperature, the reaction mixture was filtered and the solvent evaporated off to afford crude 2-[4'-(isothiocyanato)-thiophenoxy]-3-hydroxymaleic acid as an orange oil; (This material was used directly in the next step but could be crystallized from CHCl3) MP 156°-158° C. with decomposition; 1H NMR (acetone-d6, d) 10.2 (2H, br), 7.58 (2H, d, J=8.8 Hz), 7.32 (2H, d, J=8.8 Hz), 4.99 (1H, br s), 4.79 (1H, d, J=4.8 Hz), 4.26 (1H, d, J=4.8 Hz); 13C NMR (acetone-d6, d) 172.7, 171.0, 135.7, 133.7, 130.9, 127.1, 127.0, 71.7, 55.7; IR (Nujol mull, cm-1) 3390 (br, m), 2040 (s), 1730 (s), 1695 (s); mass spectrum, m/e 299, 263, 191, 166, 108, 57 (base).

1. temperatureat reflux for 30 minutes
2. temperatureUpon cooling to room temperature
3. filtrationthe reaction mixture was filtered
4. customthe solvent evaporated off