反应详情

温度

-40 °C

Preparation 1: 5-Bromomethyl-6,7-dichloro-2,3-dimethoxyquinoxaline (a) A solution of 2,4,5-trichloronitrobenzene (103 g, 0.46 mol) and t-butyl chloroacetate (79 mL, 0.55 mol) in dry tetrahydrofuran (400 mL) was added dropwise over 30 minutes to a solution of potassium t-butoxide (128 g, 1.14 mol) in dry tetrahydrofuran (800 mL) with stirring, under nitrogen keeping the temperature at -40° C. After the addition was complete, the resulting dark blue solution was stirred for a further 30 minutes. The mixture was poured into 0.5M hydrochloric acid (2 L) and the product was extracted into ethyl acetate (2.5 L and 1 L). The combined organic solutions were dried (MgSO4) and evaporated onto silica gel (70-200μ, 200 g). The silica gel was applied to the top of a silica gel chromatography column (800 g), and the product was eluted using a hexane/ethyl acetate gradient. Product-containing fractions were combined and evaporated to give a yellow solid, which was triturated with hexane to give t-butyl (2-nitro-3,5,6-trichlorophenyl)acetate (91.8 g, 59%) as a white solid. Found C, 42.32; H, 3.50; N, 4.03. C12H12Cl3 NO4 requires C, 42.32; H, 3.55, N, 4.11%.

1. customPreparation 1
2. additionAfter the addition
3. stirringthe resulting dark blue solution was stirred for a further 30 minutes
4. extractionthe product was extracted into ethyl acetate (2.5 L and 1 L)
5. dry with materialThe combined organic solutions were dried (MgSO4)
6. customevaporated onto silica gel (70-200μ, 200 g)
7. washthe product was eluted
8. customevaporated
9. customto give a yellow solid, which
10. customwas triturated with hexane