Citric Acid → 2-propargyloxy-4-(N-t-butyloxycarbonyl-4-piperidinyloxy)benzoic acid
Reaction equation
[CH2:1]([O:4][C:5]1[CH:14]=[C:13]([O:15][CH:16]2[CH2:21][CH2:20][N:19]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:18][CH2:17]2)[CH:12]=[CH:11][C:6]=1[C:7]([O:9]C)=[O:8])[C:2]#[CH:3].[OH-].[Na+].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>CO>[CH2:1]([O:4][C:5]1[CH:14]=[C:13]([O:15][CH:16]2[CH2:21][CH2:20][N:19]([C:22]([O:24][C:25]([CH3:28])([CH3:27])[CH3:26])=[O:23])[CH2:18][CH2:17]2)[CH:12]=[CH:11][C:6]=1[C:7]([OH:9])=[O:8])[C:2]#[CH:3]Participants
5
Conditions
- Temperature
- 50 °C
Procedure
Methyl 2-propargyloxy-4-(N-t-butyloxycarbonyl-4-piperidinyloxy)benzoate (467 mg, 1.2 mmol) from Step 1 above was dissolved in methanol (10 mL) and to the stirred solution was added 1N NaOH (2.4 mL). The reaction was stirred for 4 h at 50° C. The cooled reaction was acidified with 5% aqueous citric acid (25 mL). The methanol was removed under reduced pressure and the remaining aqueous was extracted with methylene chloride (4×50 mL). The combined organic extracts were washed with water and brine, dried over magnesium sulfate and filtered. The solvent was removed under reduced pressure to give 2-propargyloxy-4-(N-t-butyloxycarbonyl-4-piperidinyloxy)benzoic acid.
Workup
- customThe cooled reaction
- customThe methanol was removed under reduced pressure
- extractionthe remaining aqueous was extracted with methylene chloride (4×50 mL)
- washThe combined organic extracts were washed with water and brine
- dry with materialdried over magnesium sulfate
- filtrationfiltered
- customThe solvent was removed under reduced pressure
Sources & evidence
- ORD record
- ord-d371bace8baf473896f3663296136c64
- Source dataset
- uspto-grants-1997_09
- Patent number
- US05665719
Reaction notes
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