反应详情

温度

100 °C

To a suspension of tert-butyl 4-aminobenzoate (1.93 g, 10 mmol) and 2-bromothiazole (1.2 g, 7.3 mmol) in isopropanol (60 mL) was added 4 N HCl solution in 1,4-dioxane (0.5 mL, 2 mmol). The mixture was refluxed at 100° C. for 50 h, and then allowed to cool to room temperature. The mixture was concentrated to one third of the initial volume. The resulting precipitate was isolated by filtration to yield the first crop of the title compound as a brown solid (915 mg). The mother liquor was dried in vacuo. The obtained residue was dissolved in ethyl acetate (50 mL), washed with water (2×15 mL), dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was triturated with isopropanol (8 mL) to yield the second crop of the title compound (341 mg) (total 1.25 g, 78% yield). HPLC/MS (Method D): retention time=0.57 min, [M+H]+=221.3.

1. temperatureto cool to room temperature
2. concentrationThe mixture was concentrated to one third of the initial volume
3. customThe resulting precipitate was isolated by filtration