Hydrochloric Acid → Benzyl 3-(hydroxymethyl)piperazine-1-carboxylate
Reaction equation
CC(C)([O-])C.[K+].O.[C:8]1([CH2:14][O:15][C:16]([N:18]2[CH2:23][CH2:22][N:21]3C(=O)[O:25][CH2:26][CH:20]3[CH2:19]2)=[O:17])[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.Cl.[OH-].[Na+]>>[C:8]1([CH2:14][O:15][C:16]([N:18]2[CH2:23][CH2:22][NH:21][CH:20]([CH2:26][OH:25])[CH2:19]2)=[O:17])[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1Participants
Procedure
To a flame dried flask under an inert atmosphere containing potassium tert-butoxide (12.18 g, 108.58 mmol) and water (900 mg, 50.00 mmol) at 0° C. is added (+/-)-tetrahydro-3-oxo-3 H-oxazolo(3,4-a)pyrazin-7(1 H)-carboxylic acid phenylmethylester (Step 3, 10.00 g, 36.19 mmol). The reaction is warmed to ambient temperature, stirred for 2 hours, cooled to 0° C., acidified to pH=2 with conc. HCl, adjusted to pH=9 with 1N NaOH, and extracted with methylene chloride (2×100 mL). The organic extracts are combined, dried over Na2SO4, concentrated in vacuo, and chromatographed on silica gel (230-400 mesh, 250 mL), eluting with chloroform/methanol (95/5). The appropriate fractions are combined (Rf =0.13, TLC, chloroform/methanol, 90/10) and concentrated in vacuo to give the title compound, NMR (CDCl3) 7.34-7.25, 5.09, 3.95, 3.55-3.53, 3.41, 3.34, 2.92, 2.72-2.70.
Workup
- customTo a flame dried flask under an inert atmosphere
- temperaturecooled to 0° C.
- extractionextracted with methylene chloride (2×100 mL)
- dry with materialdried over Na2SO4
- concentrationconcentrated in vacuo
- customchromatographed on silica gel (230-400 mesh, 250 mL)
- washeluting with chloroform/methanol (95/5)
- concentrationconcentrated in vacuo
Sources & evidence
- ORD record
- ord-542de622fae843b5a7dbb02f31ec36c4
- Source dataset
- uspto-grants-1999_07
- Patent number
- US05922707
Reaction notes
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