反应详情

To a solution of compound B (˜311 mmol) in MeOH (1.2 L) was added a solution of LiOH (14.9 g, 622 mmol) in water (120 mL). The reaction mixture was stirred at ambient temperature for 3 h. Solvents were evaporated to 75% of the initial volume followed by dilution with water (400 mL). The solution was extracted with EtOAc (2×300 mL). The organic layer was washed with brine (200 mL), dried over MgSO4 and evaporated in vacuo. The residue was dissolved in ether (300 mL) and treated with 2 N HCl/ether (200 mL). Formed precipitate was filtrated, washed with ether and dried in vacuo to provide the hydrochloric salt of compound C (67.8 g, 89%) as a white solid. LC-MS [M+H] 209.0 (C11H16N2O2+H, calc: 209.3). Compound C was used directly in the next reaction without purification as a DMF solution.

1. customSolvents were evaporated to 75% of the initial volume
2. extractionThe solution was extracted with EtOAc (2×300 mL)
3. washThe organic layer was washed with brine (200 mL)
4. dry with materialdried over MgSO4
5. customevaporated in vacuo
6. dissolutionThe residue was dissolved in ether (300 mL)
7. additiontreated with 2 N HCl/ether (200 mL)
8. customFormed precipitate
9. filtrationwas filtrated
10. washwashed with ether
11. customdried in vacuo