反应详情

温度

5 °C

To a solution of 2-ethoxymethylenemalonic acid diethyl ester (59.0 g, 273 mmol) in EtOH (300 mL) was added 2-methyl-isothiourea (41.5 g, 150 mmol) in an ice-H2O bath. An EtOHic solution of EtONa (2M, 300 mL) was added dropwise maintaining the reaction temperature under 5° C. The mixture was warmed to RT and stirred for 3 h. After standing overnight, the solvent was removed under reduced pressureand the residue was dissolved in H2O (800 mL) at 0° C. The solution was acidified to pH 3 with conc. HCl and the precipitate collected by filtration and air-dried to yield 4-hydroxy-2-methylsulfanyl-pyrimidine-5-carboxylic acid ethyl ester as a white solid (50.8 g, 87.6% yield). 1H NMR (400 MHz, DMSO-d6): δ 8.48 (s, 1H), 4.20 (q, J=9.6 Hz, 2H), 2.51 (s, 3H), 1.23 (t, J=9.6 Hz, 3H).

1. temperatureThe mixture was warmed to RT
2. waitAfter standing overnight
3. customthe solvent was removed
4. dissolutionwas dissolved in H2O (800 mL) at 0° C
5. filtrationthe precipitate collected by filtration
6. customair-dried