反应详情

温度

100 °C

2.00 g (8.80 mmol) of contaminated 4-(2,3-dihydroimidazo[2,1-b]thiazol-5-yl)benzonitrile is placed in 60 mL of 50% acetic acid solution at 0° C. and slowly combined with 30 mL of concentrated sulfuric acid with stirring and cooling in the ice bath. The reaction mixture is heated to 100° C. for 17 hours and then poured into 500 mL of ice water. The precipitated product formed is filtered off. The mother liquor is combined with sodium chloride and extracted with 300 mL of ethyl acetate, washed with saturated sodium chloride solution, dried with magnesium sulfate, and the solvent is distilled off. The residue remaining is combined with the above precipitate. Yield: 1.25 g (40% over 2 steps); Rf value: 0.55 (silica gel; ethyl acetate/ethanol=9:1); C12H10N2O2S (246.29); mass spectrum: (M+H)+=247

1. customThe precipitated product formed
2. filtrationis filtered off
3. extractionextracted with 300 mL of ethyl acetate
4. washwashed with saturated sodium chloride solution
5. dry with materialdried with magnesium sulfate
6. distillationthe solvent is distilled off