反应详情

4.48 g (19.2 mmol, 80%) Methanesulfonic acid 2,2-difluoro-cyclopropylmethyl ester are added to 5.93 g (19.2 mmol, 90%) 4-(4-hydroxy-phenyl)-piperidine-1-carboxylic acid tert-butyl ester and 5.36 g (38.5 mmol) K2CO3 in 60 mL DMF. Stirring is continued for 12 h at 50° C. under inert gas atmosphere. After that time, brine (50 mL) is added and the mixture is extracted with EtOAc (3×50 mL). The organic layer is separated, washed with brine, dried over sodium sulphate and the solvent is removed by evaporation. The residue is purified by column chromatography (silica gel; gradient PE:EtOAc 20:1→10:1). The residue is taken up in 20 mL DCM and 100 mL 4N HCl in EtOAc are added dropwise at 0° C. The mixture is stirred for 12 h at rt. After that time, the solvent is removed in vacuo to yield the desired product.

1. extractionthe mixture is extracted with EtOAc (3×50 mL)
2. customThe organic layer is separated
3. washwashed with brine
4. dry with materialdried over sodium sulphate
5. customthe solvent is removed by evaporation
6. customThe residue is purified by column chromatography (silica gel; gradient PE:EtOAc 20:1→10:1)
7. addition100 mL 4N HCl in EtOAc are added dropwise at 0° C
8. stirringThe mixture is stirred for 12 h at rt
9. customAfter that time, the solvent is removed in vacuo