反应详情

5-bromo-1,3,4-thiadiazol-2-amine (1 g, 5.55 mmol, 1 eq) and chloroacetone (1.327 mL, 16.665 mmol, 3 eq) in water (24 mL) was stirred at reflux temperature overnight. More chloroacetone (1.106 mL, 13.887 mmol, 2.5 eq) was added, and heating was continued over the weekend. The reaction mixture was cooled to RT, poured into NaHCO3 (sat. sol., 43 mL) and extracted with DCM. The organic extracts were dried (MgSO4), filtered and concentrated to give a dark brown residue that was purified by flash chromatography (SiO2, DCM) affording the desired product (white solid, 0.613 g, 50%). HPLC-MS (10-95% B in 4 min at 0.5 mL+2 min 100% B, flow 0.7 mL/min): tR=4.81 min, [M+H]+ m/z 217.9; 1H NMR (300 MHz, CDCl3) δ 7.47 (s, 1H), 2.32 (s, 3H).

1. temperatureat reflux temperature overnight
2. temperatureheating
3. extractionextracted with DCM
4. dry with materialThe organic extracts were dried (MgSO4)
5. filtrationfiltered
6. concentrationconcentrated
7. customto give a dark brown residue that
8. customwas purified by flash chromatography (SiO2, DCM)