反应详情

A mixture of (±)-1,1-dimethylethyl cis-4-[[(4-amino-5-chloro-2-methoxybenzoyl)oxy]-methyl]-3-hydroxy-1-piperidinecarboxylate (0.053 mol) in THF (250 ml) and a mixture of HCl and 2-propanol (25 ml) was stirred for 2 hours at room temperature, then for 10 minutes at 50° C., then cooled again to room temperature. The mixture was alkalinized with NH3. The organic layer was separated, dried (MgSO4), filtered and the solvent was evaporated. The residue was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 90/10). The pure fractions were collected and the solvent was evaporated, yielding 4.6 g (29%) (±) cis-(3-hydroxy-4-piperidinyl)methyl 4-amino-5-chloro-2-methoxybenzoate (interm. 6-a).

1. waitfor 10 minutes at 50° C.
2. temperaturecooled again to room temperature
3. customThe organic layer was separated
4. dry with materialdried (MgSO4)
5. filtrationfiltered
6. customthe solvent was evaporated
7. customThe residue was purified by column chromatography over silica gel (eluent: CH2Cl2 /(CH3OH/NH3) 90/10)
8. customThe pure fractions were collected
9. customthe solvent was evaporated