反应详情

温度

60 °C

To the suspension of 2,4-dibromo-1,3-thiazole-5-carboxamide (0.110 g, 0.385 mmol) in dry Toluene (8.0 mL, 75 mmol) was added DMFDMA (0.204 mL, 1.54 mmol). The mixture was stirred at 60° C. under N2 atmosphere for 3 hours. The solvent was removed and to the intermediate was added acetic acid (2.0 mL, 35 mmol), followed by hydrazine (0.0604 mL, 1.92 mmol). The mixture was heated to 120° C. for 30 min. The mixture was cooled to room temperature, solvent was removed and the residual acetic acid was azeotroped with toluene (2×5 mL) to give an oily material, which was basified with saturated aqueous NaHCO3 to pH˜8 and extracted with EtOAc (3×30 mL). The EtOAc layer was washed with water, brine, dried over Na2SO4, filtered, and evaporated to give a crude product. Chromatography on a silica column using EtOAc/hexane (0/100 to 50/50) gave a solid product (0.073 g, 61%). LCMS: (FA) ES+ 311 and ES− 309.111 NMR (400 MHz, d4-Methanol) 8.53 (s, 1H).

1. customThe solvent was removed and to the intermediate
2. temperatureThe mixture was heated to 120° C. for 30 min
3. temperatureThe mixture was cooled to room temperature
4. customsolvent was removed
5. customthe residual acetic acid was azeotroped with toluene (2×5 mL)
6. customto give an oily material, which
7. extractionextracted with EtOAc (3×30 mL)
8. washThe EtOAc layer was washed with water, brine
9. dry with materialdried over Na2SO4
10. filtrationfiltered
11. customevaporated
12. customto give a crude product