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tekst:
5 g of .... were cut into small pieces and extracted by reflux with 0.4 g of sodium hydroxide in 25 ml of methanol for 1 to 2 hrs. The methanol extract was then filtered to remove particulate materials. After addition of 1 g of filter aid to the methanol extract, which contained 465 to 485 mg of ...., the methanol was removed under reduced pressure. The residue was then mixed with 5.5 ml of 1.0 N sodium hydroxide solution at 35.degree. C. for 10 min. and the pH adjusted to about 11.5 to 11.9 with 50% acetic acid in water. This aqueous extract was then filtered and the precipitate washed with 5.5 ml of 0.01 N sodium hydroxide solution. The combined aqueous filtrate was stirred with 0.5 g of sodium acetate for 10 minutes and filtered again. The filtrate was then extracted twice with 5 ml of toluene and the pH of the aqueous filtrate was then adjusted to pH 9.1, with 50% acetic acid in water. The mixture was allowed to remain for a period of 6-10 hrs at room temperature for complete precipitation and was then filtered. This precipitate was washed with water and dried at room temperature. This final precipitate contained 400-426 mg of ...., which represented a recovery of 86-88% based upon the amount of p. in the initial methanol extract. The purity of .... following this procedure was 84% to 86% by weight.
tekst:
5 g of .... were cut into small pieces and extracted by reflux with 0.4 g of sodium hydroxide in 25 ml of methanol for 1 to 2 hrs. The methanol extract was then filtered to remove particulate materials. After addition of 1 g of filter aid to the methanol extract, which contained 465 to 485 mg of ...., the methanol was removed under reduced pressure. The residue was then mixed with 5.5 ml of 1.0 N sodium hydroxide solution at 35.degree. C. for 10 min. and the pH adjusted to about 11.5 to 11.9 with 50% acetic acid in water. This aqueous extract was then filtered and the precipitate washed with 5.5 ml of 0.01 N sodium hydroxide solution. The combined aqueous filtrate was stirred with 0.5 g of sodium acetate for 10 minutes and filtered again. The filtrate was then extracted twice with 5 ml of toluene and the pH of the aqueous filtrate was then adjusted to pH 9.1, with 50% acetic acid in water. The mixture was allowed to remain for a period of 6-10 hrs at room temperature for complete precipitation and was then filtered. This precipitate was washed with water and dried at room temperature. This final precipitate contained 400-426 mg of ...., which represented a recovery of 86-88% based upon the amount of p. in the initial methanol extract. The purity of .... following this procedure was 84% to 86% by weight.
