Sodium borohydride → HCID 14838430, compound
Reaction equation
[BH4-].[Na+].Cl.[CH3:4][O:5][C:6]([C:8]1[CH2:9][N:10]([CH2:15][CH2:16][CH:17]2[O:22][C:21]3[CH:23]=[CH:24][CH:25]=[CH:26][C:20]=3[O:19][CH2:18]2)[CH2:11][CH2:12][C:13]=1[OH:14])=[O:7].Cl.COC(C1C(=O)CCN(CCC2OC3C=CC=CC=3OC2)C1)=O>CO>[CH3:4][O:5][C:6]([C@H:8]1[C@H:13]([OH:14])[CH2:12][CH2:11][N:10]([CH2:15][CH2:16][CH:17]2[O:22][C:21]3[CH:23]=[CH:24][CH:25]=[CH:26][C:20]=3[O:19][CH2:18]2)[CH2:9]1)=[O:7]Participants
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
At -15° and while stirring, 2.65 g (70 mmol) of sodium borohydride are added in portions over a period of one hour to a suspension of 12.45 g (35 mmol) of 1-[2-(benzo-1,4-dioxan-2-yl)ethyl]-4-hydroxy-1,2,5,6-tetrahydropyridine-3-carboxylic acid methyl ester hydrochloride or 1-[2-(benzo-1,4-dioxan-2-yl)ethyl]-4-oxopiperidine-3-carboxylic acid methyl ester hydrochloride, respectively, in 250 ml of methanol. Stirring is continued for a further 4 hours at -10° and then the reaction mixture is concentrated by evaporation in vacuo and taken up in water/ethyl acetate. The ethyl acetate extracts are washed with water, dried over sodium sulphate and concentrated by evaporation. 11.2 g (100%) of crude product are obtained which are chromatographed on 560 g of silica gel (0.040-0.063 mm) using ethyl acetate as the eluant. 5.41 g (48.2%) of trans-1-[2-(benzo-1,4-dioxan-2-yl)ethyl]-4-hydroxypiperidine-3-carboxylic acid methyl ester are obtained in the form of a pale yellow oil. The trans-1-[2-(benzo-1,4-dioxan-2-yl)ethyl]-4-hydroxypiperidine-3-carboxylic acid methyl ester fumarate produced therefrom using fumaric acid crystallises from methanol/diethyl ether in the form of the hemihydrate having a melting point of 150°-152°.
Workup
- stirringStirring
- concentrationthe reaction mixture is concentrated by evaporation in vacuo
- washThe ethyl acetate extracts are washed with water
- dry with materialdried over sodium sulphate
- concentrationconcentrated by evaporation
- custom11.2 g (100%) of crude product are obtained which
- customare chromatographed on 560 g of silica gel (0.040-0.063 mm)
Sources & evidence
- ORD record
- ord-56bf6c970be74276acb3df7dcb0d0c4b
- Source dataset
- uspto-grants-1992_05
- Patent number
- US05112855
Reaction notes
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