反应详情

温度

120 °C

A solution of 2-cyanothiazole (1.55 g, 14.2 mmol) in MeOH (12 mL) is treated with N-acetylcysteine (234 mg, 1.42 mmol), ammonium acetate (1.5 g, 18.5 mmol) and heated in a microwave at 120° C. for 15 min. The mixture is then treated with 2-dimethylaminomethylene-3-oxo-butyric acid ethyl ester (3.2 g, 17.0 mmol) and KOt-Bu (2.2 g, 20 mmol), and heated in a microwave at 120° C. for an additional 15 min. The mixture is then treated with a solution of KOH (1.2 g, 20 mmol) in H2O (5 mL) and heated at reflux for 1 h. The mixture is neutralized with concentrated aqueous HCl. The precipitate is collected by filtration and dried to afford 4-methyl-2-thiazol-2-yl-pyrimidine-5-carboxylic acid (1.95 g, 62%). MS: 222 (M+H); 1H NMR (300 MHz, DMSO-d6): δ 13.77 (s. OH, 1H), 9.18 (s, 1H), 8.13 (d, 1H), 8.07 (d, 1H), 2.81 (s, 3H).

1. temperatureheated in a microwave at 120° C. for an additional 15 min
2. temperatureheated
3. temperatureat reflux for 1 h
4. filtrationThe precipitate is collected by filtration
5. customdried