Acetonitrile → N,N-Bis[2-((phenoxycarbonyl)oxy)ethyl]-N,N-dimethylammonium Methylsulfate

Beteiligte Stoffe

Reaktionsschritte

To a 500 ml three-necked round-bottomed flask equipped with an internal thermometer, reflux condenser, mechanical stirrer, addition funnel, and argon inlet are added N-methyldiethanolamine (20.00 g, 0.168 mol), toluene (200 ml), and triethylamine (37.36 g, 0.369 mol). The mixture is treated with a solution of phenylchloroformate (52.56 g, 0.336 mol) dissolved in 50 ml of toluene so as to maintain the reaction temperature at 35°-45° C. After addition is complete, the mixture is heated at 45° C. for an additional 1.5 h. The cooled mixture is washed with saturated sodium bicarbonate solution (2×200 ml) and water (200 ml). The organic phase is dried over MgSO4, filtered, and concentrated first by rotary evaporation at 50° C. (water aspirator vacuum) and then at 80° C. (0.02 mmHg) in a Kugelrohr oven to give 3 as a light yellow oil, 55.65 g (92%) that crystallizes on standing. Preparation of N,N-Bis[2-((phenoxycarbonyl)oxy)ethyl]-N,N-dimethylammonium Methylsulfate (4). To a 1000 ml three-necked round-bottomed flask fitted with a reflux condenser, magnetic stirrer, internal thermometer, addition funnel, and argon inlet are added N,N-bis[2-((phenoxycarbonyl)oxy)ethyl]-N-methylamine (100.00 g, 0.278 mol), acetonitrile (270 ml), and dimethylsulfate (35.93 g, 0.278 mol) over 10 min. After addition is complete, the mixture is heated to reflux for 2 h. The cooled mixture is treated with ether (500 ml). The product precipitates from the mixture after approximately 15 min to give 4 as a white powder, 126.26 g (93%): mp 85°-87° C.

Herkunft & Nachweise