Sodium Chloride → 1,4-Dioxa-8-azaspiro(4.5)decane

Participants

Reaction Steps

To a 30 L reactor equipped with a mechanic stirrer, an addition funnel and a septum was charged sodium hydroxide (NaOH, 1.4 kg, 35 mol, 2.0 equiv) and water (7 L) and the resulting solution was treated with 1,4-dioxa-8-azaspiro[4.5]decane hydrochloride (3.13 kg, 17.43 mol) at ambient temperature. The resulting mixture was then stirred at ambient temperature for 30 minutes before being saturated with solid sodium chloride (1.3 kg) and extracted with 2-methyl-tetrahydrofuran (3×7 L). The combined organic phase was dried with anhydrous sodium sulfate (Na2SO4, 1.3 kg) and concentrated under reduced pressure (70 mmHg) at 50° C. after removal of the drying reagent, sodium sulfate (Na2SO4), by filtration. The yellow oil thus obtained was distilled under reduced pressure (80 mmHg, by 115 to 120° C.) to afford 1,4-dioxa-8-azaspiro[4.5]decane (2.34 kg, 2.496 kg theoretical, 93.8%) as a clear oil, which was used directly in the subsequent coupling reaction.

Provenance & Evidence