反应详情

温度

100 °C

4-Amino-phenol (2.54 g, 22.8 mmol, 1.1 equiv) is added in one portion to a suspension of NaH (60% free-flowing powder moistened with oil, 1.25 g, 31.2 mmol, 1.5 equiv) in dioxane abs. (30 mL), under an argon atmosphere. When hydrogen evolution subsides, 4-nitro-pyridine N-oxide (3 g, 20.8 mmol) is added in one portion. The resulting dark mixture is heated to 100° C. (oil bath temperature) for 22 h and then allowed to cool to rt. Me3SiCN (3.5 mL, 27.0 mmol, 1.3 equiv) is added. After 5 min, the reaction mixture is cooled with a 10° C. water bath and N,N-dimethylcarbamoyl chloride (2.5 mL, 27.0 mmol, 1.3 equiv) Is added dropwise. The reaction mixture is allowed to warm to rt. When the reaction becomes exothermic, the water bath (10° C.) is applied for a few minutes. The reaction mixture is allowed to warm to rt, stirred for 1 h, quenched by addition of MeOH (30 mL), and concentrated in vacuo. After addition of CH2Cl2 to the residue, the resulting suspension is filtered through a glass sintered funnel (washing with copious amount of the same solvent). The filtrate is concentrated in vacuo and the residue is purified by silica gel (200 g) column chromatography (CH2Cl2/Et2O, 90/10) to afford the title compound as a brownish solid: ES-MS: 211.9 [M+H]+; single peak at tR=4.86 min (System 2); Rf=0.44 (CH2Cl2/Et2O, 80/20).

1. temperatureto cool to rt
2. temperaturethe reaction mixture is cooled with a 10° C. water bath
3. temperatureto warm to rt
4. temperatureto warm to rt
5. customquenched by addition of MeOH (30 mL)
6. concentrationconcentrated in vacuo
7. additionAfter addition of CH2Cl2 to the residue
8. filtrationthe resulting suspension is filtered through a glass sintered funnel (
9. washwashing with copious amount of the same solvent)
10. concentrationThe filtrate is concentrated in vacuo
11. customthe residue is purified by silica gel (200 g) column chromatography (CH2Cl2/Et2O, 90/10)