Formic Acid → Methylephedrine

Beteiligte Stoffe

Reaktionsschritte

Ephedrine hydrochloride (30.3 g, 0.15 mol) was dissolved in warm water (60 ml) there was, then added thereto a 40% sodium hydroxide aqueous solution (15 ml, 0.15 mol) and 85% formic acid (21.7 g, 0.4 mol) and the mixtures refluxed under heating, and to this solution was added dropwise a 35% formalin solution (15 g, 0.18 mol) over 20 minutes. Thereafter, refluxing under heating was continued for 3 hours and the reaction solution was concentrated to 1/2 of its original volume and then added thereto was a 40% sodium hydroxide aqueous solution to adjust the pH to about 11. The resultant precipitated crystals were filtered out and recrystallized from methanol. Yield: 23 g (84%); m.p.: 86.5°-87.5° C. [α]D20 =-29.5° (C=4.54, MeOH).

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