反应详情

The yellow oil obtained from Example 4 above was dissolved in 700 ml of methanol, and 100 ml. of 5 sodium hydroxide was added. The mixture was stirred for 2 hours at ambient temperature, and then the solvent was removed under vacuum. The residue was dissolved in 500 ml. of water and was washed with two 500 ml portions of diethyl ether. The water layer was acidified to pH 2 with cold methanesulfonic acid, was diluted to about 3 liters, and was washed again with two 1 liter portions of diethyl ether. The aqueous layer was separated, degassed under vacuum, and made basic by addition of sodium bicarbonate. A precipitate developed, and was collected by filtration and washed with water. The solids were vacuum dried at 70° C. to obtain 13 g. of impure product, which was dissolved in 500 ml. of hot acetone, filtered and evaporated down to approximately 100 ml. volume. The solution was cooled and scratched to obtain 11.3 g of product.

1. customthe solvent was removed under vacuum
2. dissolutionThe residue was dissolved in 500 ml
3. washof water and was washed with two 500 ml portions of diethyl ether
4. additionwas diluted to about 3 liters
5. washwas washed again with two 1 liter portions of diethyl ether
6. customThe aqueous layer was separated
7. customdegassed under vacuum
8. additionmade basic by addition of sodium bicarbonate
9. filtrationwas collected by filtration
10. washwashed with water
11. customdried at 70° C.
12. customto obtain 13 g
13. dissolutionof impure product, which was dissolved in 500 ml
14. filtrationof hot acetone, filtered
15. customevaporated down to approximately 100 ml
16. temperatureThe solution was cooled