反应详情

Trifluoromethanesulfonic anhydride (492 g, 1.74 mol, 1.1 eq) in dichloromethane (0.5 L) was added over 1.5 hours to a suspension of methyl 2-hydroxy-1-naphthoate (319 g, 1.58 mol) and pyridine (330 ml, 4.08 mol, 2.6 eq) in dichloromethane (1.7 L) maintained at an internal temperature between −70 and −50° C., under nitrogen. Once the addition was complete, the mixture was allowed to warm to ambient temperature and stirred for 16 hours, after which time all solids had dissolved. Methyl tert-butyl ether (MTBE, 2.5 L) was added, causing precipitation. The solids were removed by filtration and washed with MTBE (0.5 L). The MTBE solutions were combined and washed with 2 N HCl(aq) (0.3 L then 0.2 L), water (2×2.5 L) and brine (2 L). The organic layer was dried (MgSO4), filtered and concentrated under reduced pressure. The residue was dissolved in toluene (2.5 L) and washed with 1 N NaOH (aq) (0.5 L), water (2.5 L) and brine (1 L). The toluene solution was dried (MgSO4), filtered and concentrated under reduced pressure. Initially a slightly brown oil, the product crystallised on standing. Yield 438.5 g, 83%

1. temperaturemaintained at an internal temperature between −70 and −50° C., under nitrogen
2. additionOnce the addition
3. dissolutionafter which time all solids had dissolved
4. customprecipitation
5. customThe solids were removed by filtration
6. washwashed with MTBE (0.5 L)
7. washwashed with 2 N HCl(aq) (0.3 L
8. dry with materialThe organic layer was dried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. dissolutionThe residue was dissolved in toluene (2.5 L)
12. washwashed with 1 N NaOH (aq) (0.5 L), water (2.5 L) and brine (1 L)
13. dry with materialThe toluene solution was dried (MgSO4)
14. filtrationfiltered
15. concentrationconcentrated under reduced pressure
16. customInitially a slightly brown oil, the product crystallised