Water → methyl 1-(1-benzyloxycarbonylpiperidin-4-yl)-1H-indole-6-carboxylate
Reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][C:11]=1[CH2:12][CH:13](OC)OC)[C:5]([O:7][CH3:8])=[O:6].O=[C:19]1[CH2:24][CH2:23][N:22]([C:25]([O:27][CH2:28][C:29]2[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=2)=[O:26])[CH2:21][CH2:20]1.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].O>C(O)(=O)C>[CH2:28]([O:27][C:25]([N:22]1[CH2:23][CH2:24][CH:19]([N:1]2[C:2]3[C:11](=[CH:10][CH:9]=[C:4]([C:5]([O:7][CH3:8])=[O:6])[CH:3]=3)[CH:12]=[CH:13]2)[CH2:20][CH2:21]1)=[O:26])[C:29]1[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=1Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 1
Procedure
44.3 g of methyl 3-amino-4-(2,2-dimethoxyethyl)benzoate synthesized according to the publication (Tetrahedron Letters, Vol. 37, No. 34, pp. 6045-6048) and 64.9 g of benzyl 4-oxo-1-piperidinecarboxylate were dissolved in 485 ml of acetic acid, followed by stirring at room temperature. Approximately 20 minutes later, 58.9 g of sodium triacetoxyborohydride was added to the reaction solution. Then, the reaction solution was further stirred for 2 hours. Thereafter, 485 ml of water was added to the reaction solution, and the obtained mixture was heated to a temperature between 100° C. and 115° C. Approximately 3 hours later, the reaction solution was cooled, and then concentrated under a reduced pressure. Thereafter, water and ethyl acetate were added thereto, so as to separate an organic layer. The obtained organic layer was washed with a saturated sodium bicarbonate aqueous solution and a saturated sodium chloride solution, and dried over anhydrous magnesium sulfate. After removing the drying agent by filtration, the organic layer was concentrated under a reduced pressure, and the residue was then purified by NH silica gel column chromatography (hexane/ethyl acetate). The obtained solid was suspended in a mixed solvent consisting of hexane and t-butylmethyl ether, followed by filtration, so as to obtain 64.6 g of the subject compound.
Workup
- stirringThen, the reaction solution was further stirred for 2 hours
- temperaturethe obtained mixture was heated to a temperature between 100° C. and 115° C
- temperatureApproximately 3 hours later, the reaction solution was cooled
- concentrationconcentrated under a reduced pressure
- additionThereafter, water and ethyl acetate were added
- customso as to separate an organic layer
- washThe obtained organic layer was washed with a saturated sodium bicarbonate aqueous solution
- dry with materiala saturated sodium chloride solution, and dried over anhydrous magnesium sulfate
- customAfter removing the drying agent
- filtrationby filtration
- concentrationthe organic layer was concentrated under a reduced pressure
- customthe residue was then purified by NH silica gel column chromatography (hexane/ethyl acetate)
- filtrationfollowed by filtration
Sources & evidence
- ORD record
- ord-a969e02125f649b4ab785d38244d7c3e
- Source dataset
- uspto-grants-2009_05
- Patent number
- US07538123B2
Reaction notes
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