反应详情

Sodium bis(trimethylsilyl)amide (5 ml) was added to a solution of 1,3-dihydro-2H-imidazol-2-one (0.84 g) in DMF (50 ml), stirred under a N2 flow and cooled in an ice-bath. The reaction mixture was stirred for 30 minutes. Intermediate 1 (2.69 g) was added portionwise and the resulting reaction mixture was stirred for 16 hours at RT, then for 2 hours at 50° C. The reaction mixture was stirred in methyl isobutyl ketone/water (200 ml/50 ml). The solvent was evaporated and methyl isobutyl ketone (100 ml) was added and azeotroped on the rotary evaporator. The mixture was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 97/3). The desired fractions were collected and the solvent was evaporated. The white solid was stirred in diisopropyl ether, filtered off, washed with DIPE and dried, yielding 0.4 g (12.6%) of 1-[2-[3-(cyclopentyloxy)-4-methoxyphenyl]-2-oxo-ethyl]-1,3-dihydro-2H-imidazol-2-one (interm. 2; mp. 201.1° C.).

1. temperaturecooled in an ice-bath
2. stirringThe reaction mixture was stirred for 30 minutes
3. customthe resulting reaction mixture
4. stirringwas stirred for 16 hours at RT
5. customThe solvent was evaporated
6. additionmethyl isobutyl ketone (100 ml) was added
7. customazeotroped on the rotary evaporator
8. customThe mixture was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 97/3)
9. customThe desired fractions were collected
10. customthe solvent was evaporated
11. stirringThe white solid was stirred in diisopropyl ether
12. filtrationfiltered off
13. washwashed with DIPE
14. customdried