Ethanol → 2-Hydroxy-7-oxa-4-azaspiro[3.5]nonan-4-ium chloride

온도

250 °C

To a 1 L 3-neck round bottom flask, fitted with a thermocouple, nitrogen inlet and a 250 ml addition funnel, was charged morpholine (91.5 g, 91.5 ml, 1.05 mole, 1.0 eq.) and 100 ml of ethanol. The solution was stirred rapidly while adding epichlorohydrin (100 g, 84.5 ml, 1.08 mole, 1.03 eq.) from the addition funnel over about 30 minutes. The temperature was monitored and when the pot temperature reached 27° C., the reaction was cooled with an ice water bath. The clear solution was stirred for 18 hours. The reaction was assayed by GC (dilute 5 drops of reaction mixture into 1 ml of ethanol and inject onto a 15 m DB-5 capillary GC column with the following run parameters, Injector 250° C., detector 250° C., initial oven temperature 28° C. warming to 250° C. at 10° C. per minute.) The reaction was complete with less than 3% morpholine remaining. The reaction was concentrated on the rotoevaporated at 50° C. with full house vacuum until no more distillate could be condensed. The resulting oil was stored at room temperature for 24-48 hours or until a significant mass of crystals was observed (seeded will speed up the process). The slurry was diluted with 250 ml of acetone and filtered. The solids were dried in the vacuum oven at 60° C. for 18-24 hours. This provided 84 g of crystalline product. The mother liquors could be concentrated and the crystallization process repeated in increase recovery. 1H NMR (400 MHz, DMSO-d6) δ 6.55 (d, 1H), 4.64 (m, 1H), 4.53 (m, 2H), 4.18 (m, 2H), 3.74 (m, 4H), 3.60 (m, 2H), 3.48 (m, 2H). 13C NMR (100 MHz, DMSO-d6) δ 70.9, 61.39, 61.04, 60.25, 58.54, 57.80.