反应详情

To a nitrogen flushed 5 L 3 neck round bottom flask equipped with a mechanical stirrer, a dropping funnel, and a nitrogen inlet was charged with 697.3 g (1.68 mol) of the crude product of Step A and 2 L of methanol. 500 mL of 5.0N (1.5 eq) aqueous sodium hydroxide was added over a 20 minute period via an addition funnel. The reaction mixture was stirred at room temperature for an additional 1 hr at which point TLC analysis (CH2Cl2 -MeOH-NH4OH 90:10:1) indicated that the starting material had been consumed. The reaction mixture neutralized with 420 mL of 6N HCl, and the bulk of the organic solvent was removed in vacuo. The residue was dissolved in ether and extracted with a combination of aqueous NaOH and NaHCO3. The aqueous layer was extracted with ether and the combined organic layer was washed with aqueous NaHCO3. The aqueous layer was acidified with HCl and extracted with ether. The ether solution was dried with magnesium sulfate, filtered, and concentrated to afford 708.9 g (theoretical 625 g) of the title compound as a viscous orange oil. NMR indicated that it was ca. 85% product by weight (15% ether) thus providing a corrected yield of 602.6 g (96.4% yield)

1. customTo a nitrogen flushed 5 L 3 neck round bottom flask
2. customequipped with a mechanical stirrer, a dropping funnel, and a nitrogen inlet
3. customhad been consumed
4. customthe bulk of the organic solvent was removed in vacuo
5. dissolutionThe residue was dissolved in ether
6. extractionextracted with a combination of aqueous NaOH and NaHCO3
7. extractionThe aqueous layer was extracted with ether
8. washthe combined organic layer was washed with aqueous NaHCO3
9. extractionextracted with ether
10. dry with materialThe ether solution was dried with magnesium sulfate
11. filtrationfiltered
12. concentrationconcentrated