1. Ephedrine can be extracted from Ephedra. Cut the stems and branches of Ephedra into 2-4 cm lengths, add 7 times the amount of water, soak and boil 5 times with 0.15MPA hot press for a total of 16 hours to obtain an aqueous solution containing total alkaloids of Ephedra. After the decoction is alkalized to pH 12 with sodium hydroxide, extract it with 2 times the amount of toluene at 60-70°C. Add 2% oxalic acid solution to the toluene extract to make the pH of the toluene layer 7, transfer the total alkaloids in the toluene extract to the oxalic acid solution, separate the toluene layer, and obtain a dilute oxalate solution of total alkaloids of Ephedra. Concentrate the dilute oxalic acid solution containing alkaloids at 70°C under reduced pressure and cool to 30°C. The solubility of ephedrine oxalate in water is relatively low, and the mother liquor contains pseudoephedrine oxalate.
2. Add 8-10 times water and 1.5% activated carbon, boil, filter, and add calcium chloride solution to the filtrate under stirring until no precipitation or turbidity occurs to obtain ephedrine hydrochloride solution. Then add sodium sulfide solution to pH 7.5-8, and precipitate impurities such as calcium oxalate and iron sulfide. After filtering, take the supernatant and add hydrochloric acid to adjust the pH to 6-6.5, filter, reduce the pressure and concentrate the solution, cool to 30°C, crystallize, centrifuge, and dry to obtain the finished product.
3. Alkalize the mother liquor containing pseudoephedrine oxalate with sodium hydroxide to separate pseudoephedrine, and then acylate, transfer, hydrolyze, and neutralize to obtain ephedrine oxalate crystals, and then treat as above to obtain ephedrine hydrochloride.
Is this method okay?
