反应详情

温度

55 °C

The crude mixture of ethyl 4-[hydroxy(1,3-thiazol-2-yl)methyl]cyclohexanecarboxylate (34 g) was diluted with DMF (220 mL) and NBS (23 g, 129 mmol) was added. The resulting mixture was heated to 55° C. and stirred until the starting materials were consumed, at which point the heating mantle was removed. Water (220 mL) containing sodium sulfite (10 g) was added followed by EtOAc. The layers were separated, the organics washed a second time with water, then dried with MgSO4, filtered and concentrated in vacuo. The crude residue was absorbed on silica and purified by flash chromatography to afford racemic ethyl trans-4-[(5-bromo-1,3-thiazol-2-yl)(hydroxy)methyl]cyclohexanecarboxylate as a white solid and racemic ethyl cis-4-[(5-bromo-1,3-thiazol-2-yl)(hydroxy)methyl]cyclohexanecarboxylate as a yellow oil. Characterization data for the trans isomer: MS ESI calc'd. for C13H19BrNO3S [M+H]+ 348, 350. found 348, 350. 1H NMR (600 MHz, CDCl3) δ 7.53 (d, J=4.3, 1H), 4.66 (d, J=5.0, 1H), 4.06 (q, J=7.1, 2H), 2.20-2.16 (m, 1H), 1.97 (d, J=13.3, 2H), 1.80-1.72 (m, 2H), 1.68 (d, J=12.6, 1H), 1.43-1.31 (m, 2H), 1.25-1.13 (m, 5H).

1. additionwas added
2. customwere consumed, at which point the heating mantle
3. customwas removed
4. additionWater (220 mL) containing sodium sulfite (10 g)
5. additionwas added
6. customThe layers were separated
7. washthe organics washed a second time with water
8. dry with materialdried with MgSO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. customThe crude residue was absorbed on silica
12. custompurified by flash chromatography