反応 #60132

反応方程式

methanol

methyl 2-phenylthioprop-2-enoate

methanol

tert-butoxide

1-(2,4-dichlorophenyl)-2-imidazol-2-ylethan-1-one

methyl 2-phenylthioprop-2-enoate

→

methyl 5-(2,4-dichlorophenyl)-4-imidazol-2-yl-5-oxo-2-phenylthiopentanoate

収率 71.0%

溶媒

dichloromethane

dichloromethane

tert-butanol

反応条件

後処理

1. 1
   その他at room temperature
2. 2
   その他The reaction, which
3. 3
   その他(ca. 16 h)
4. 4
   その他to consume all of the starting 1-(2,4-dichlorophenyl)-2-imidazol-2-ylethan-1-one
5. 5
   その他The reaction was quenched by the addition of sat. aq. NH4Cl (˜100 ml)
6. 6
   その他The mixture was transferred to a separatory funnel
7. 7
   workup.ADDITIONdiluted with ethyl acetate (300 ml)
8. 8
   その他The aqueous layer was removed
9. 9
   洗浄the organic layer was washed with sat. aq. NH4Cl (3×100 ml), brine (100 ml)
10. 10
    乾燥dried with Na2SO4
11. 11
    ろ過After filtration and evaporation
12. 12
    その他the residue was purified by flash chromatography over silica gel
13. 13
    洗浄The column was eluted
14. 14
    その他to remove the non-polar methyl 2-phenylthioprop-2-enoate
15. 15
    洗浄The product was eluted with 3% methanol in dichloromethane
16. 16
    その他After drying overnight in vacuo

実験手順

A solution (1 M) of tert-butoxide in tert-butanol (54.9 ml) was added to a stirred solution of 1-(2,4-dichlorophenyl)-2-imidazol-2-ylethan-1-one (0.11 M) and methyl 2-phenylthioprop-2-enoate (0.14 M) dissolved in dichloromethane (300 ml) and methanol (200 ml) at room temperature. The reaction, which developed a dark color, was typically stirred overnight (ca. 16 h) under argon. The reaction was monitored by TLC using 5% methanol in dichloromethane as the solvent system. Additional methyl 2-phenylthioprop-2-enoate was added as needed to consume all of the starting 1-(2,4-dichlorophenyl)-2-imidazol-2-ylethan-1-one. The reaction was quenched by the addition of sat. aq. NH4Cl (˜100 ml). The mixture was transferred to a separatory funnel and diluted with ethyl acetate (300 ml). The aqueous layer was removed and the organic layer was washed with sat. aq. NH4Cl (3×100 ml), brine (100 ml), and dried with Na2SO4. After filtration and evaporation, the residue was purified by flash chromatography over silica gel. The column was eluted starting with 100% dichloromethane to remove the non-polar methyl 2-phenylthioprop-2-enoate. The product was eluted with 3% methanol in dichloromethane. After drying overnight in vacuo, methyl 5-(2,4-dichlorophenyl)-4-imidazol-2-yl-5-oxo-2-phenylthiopentanoate as a deep red glass was obtained in 71% yield. A further 10% yield of product could be obtained by resubmitting side product contaminated fractions to a second purification by flash chromatography.

出典