反应详情

温度

70 °C

A solution of potassium tertiary-butylate (1.8 g, 8 mmol) in tert.-butanol (20 ml, synthesis quality, 99%) was added to 2,6-dinitrotoluene (18.2 g, 0.1 mol, dried for 3 d in high vacuum over silica gel) and paraformaldehyde (3 g, 0.1 mol) in DMSO (50 ml, synthesis quality, additionally dried for 2 d over molecular sieve 4 Å). After the addition of the potassium tertiary-butylate solution, a color change from yellow to deep violet occurred. The solution was stirred for 5 min at room temperature and for 10 min at 70° C. (oil bath temperature). It was then left to cool to room temperature, and the mixture was neutralized with conc. HCl, and diluted with H2O (300 ml) before NaCl was added until the mixture was saturated. The aqueous phase was extracted with EtOAc (3×500 ml). The combined organic phases were washed with a saturated NaCl solution (300 ml), dried over Na2SO4, filtered and concentrated under reduced pressure. The crude product (24.3 g) was dissolved in a little EtAOc at boiling temperature, mixed with petroleum ether (henceforth referred to as PE) (100 ml) and crystallized inside a freezer. The precipitate was filtered by suction and purified by column chromatography (20.7 g crude product, 300 g SiO2, 18×6.5 cm, solvent: toluene/EtOAc 5:1, 4:1, 3:1). Mixed fractions were concentrated under reduced pressure and purified by renewed column chromatography (200 g SiO2, 20×5.3 cm, solvent: toluene/EtOAc 7:1). After concentrating the pooled pure product fractions in a rotating evaporator under reduced pressure, 2-(2,6-dinitrophenyl)ethanol (13.6 g, 64%) was obtained as a yellow solid.

1. custom50 ml, synthesis quality
2. customadditionally dried for 2 d over molecular sieve 4 Å)
3. additionAfter the addition of the potassium tertiary-butylate solution
4. waitIt was then left
5. temperatureto cool to room temperature
6. additiondiluted with H2O (300 ml) before NaCl
7. additionwas added until the mixture
8. extractionThe aqueous phase was extracted with EtOAc (3×500 ml)
9. washThe combined organic phases were washed with a saturated NaCl solution (300 ml)
10. dry with materialdried over Na2SO4
11. filtrationfiltered
12. concentrationconcentrated under reduced pressure
13. dissolutionThe crude product (24.3 g) was dissolved in a little EtAOc
14. additionmixed with petroleum ether (
15. customcrystallized inside a freezer
16. filtrationThe precipitate was filtered by suction
17. custompurified by column chromatography (20.7 g crude product, 300 g SiO2, 18×6.5 cm, solvent: toluene/EtOAc 5:1, 4:1, 3:1)
18. concentrationMixed fractions were concentrated under reduced pressure
19. custompurified
20. concentrationAfter concentrating the pooled pure product fractions
21. customin a rotating evaporator under reduced pressure