反应详情

The solution of 2-[2-(dimethylamino)-ethoxy]ethanol (6.65 g, 50 mmol, 2.5 equiv.) and 4-dimethylaminopyridine (11 mg) in toluene (20 ml) is cooled to −20° C. Separate solutions of fumaryl chloride (2.3 ml, 20 mmol, 1.0 equiv.) and 1,1,3,3-tetramethylguanidine (5.0 ml, 40 mmol, 2.0 equiv.) in toluene (each 25 ml) are added dropwise simultaneously via syringe pump over 80 min. A dark suspension is formed. After complete addition, the cooling bath is removed and stirring continued at 23° C. for 40 min. Active charcoal (1.0 g) is added and the mixture is filtered over a short pad of basic Al2O3, which is further rinsed with toluene/EtOAc (360 ml). The solution is concentrated and dried in vacuo (0.05 mbar) to yield the product as a yellow oil (2.79 g, 40%).

1. customA dark suspension is formed
2. additionAfter complete addition
3. customthe cooling bath is removed
4. additionActive charcoal (1.0 g) is added
5. filtrationthe mixture is filtered over a short pad of basic Al2O3, which
6. washis further rinsed with toluene/EtOAc (360 ml)
7. concentrationThe solution is concentrated
8. customdried in vacuo (0.05 mbar)