9-Fluorenylmethyl chloroformate → 4-Piperidinecarboxylic acid
Reaction equation
C([N:18]1[CH2:23][CH2:22][C:21](C)([C:24]([OH:26])=[O:25])[CH2:20][CH2:19]1)(OCC1C2C(=CC=CC=2)C2C1=CC=CC=2)=O.C(Cl)(OCC1C2C(=CC=CC=2)C2C1=CC=CC=2)=O>>[NH:18]1[CH2:23][CH2:22][CH:21]([C:24]([OH:26])=[O:25])[CH2:20][CH2:19]1Participants
Procedure
Preparation of N-FMOC-4-methyl-4-piperidinecarboxylic acid was prepared as described in Step D of Preparation 2 utilizing the product of Step B as starting material, except as follows. After stirring the reaction mixture overnight in the presence of FMOCCl the mixture was concentrated in vacuo to remove dioxane. The aqueous phase was diluted with water and extracted with ether. The desired product was extracted into the ether phase (salt is soluble in ether). The combined ether and aqueous phase were acidified and extracted with ether. The combined ethereal phases were washed with brine, dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by flash chromatography over silica gel eluting with 5%MeOH/CH2Cl2 to give the desired product. 1H-NMR (CDCl3, 400 Mhz):1.22 (s, 3H); 1.40 (bm, 2H); 2.02 (bs, 2H); 3.05 (bs,2H); 3.75 and 3.85 (bs, 1H); 4.21 (t, 1H); 4.41 (d, 2H) 7.29 (t, 2H); 7.38 (t, 2H); 7.55 (d, 2H); 7.75 (d, 2H).
Workup
- customwas prepared
- concentrationwas concentrated in vacuo
- customto remove dioxane
- additionThe aqueous phase was diluted with water
- extractionextracted with ether
- extractionThe desired product was extracted into the ether phase (salt is soluble in ether)
- extractionextracted with ether
- washThe combined ethereal phases were washed with brine
- dry with materialdried over MgSO4
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe residue was purified by flash chromatography over silica gel eluting with 5%MeOH/CH2Cl2
Sources & evidence
- ORD record
- ord-91bd5f26f2c142be927052f4a493d3ea
- Source dataset
- uspto-grants-2000_02
- Patent number
- US06020347
Reaction notes
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