Triphenylphosphine → Ammonium Hydroxide

HRID 1793447Notes

Reaction equation

HRID 1793447 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:11]2[NH:16][CH:15]([CH2:17][NH:18][CH2:19][CH2:20]O)[CH2:14][CH2:13][CH2:12]2)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OCC)=O)=NC(OCC)=O>C1COCC1>[NH4+:16].[OH-:2].[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:11]2[N:16]3[CH2:20][CH2:19][NH:18][CH2:17][CH:15]3[CH2:14][CH2:13][CH2:12]2)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10]

Participants

6

Reactant 3

HCID 11776TriphenylphosphineHCID 220568ethyl N-ethoxycarbonyliminocarbamateHCID 22021951HCID 22021951, compound

Product 2

HCID 14923Ammonium HydroxideHCID 22021984HCID 22021984, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To the solution of 3.4 g (11.6 mmoles, 1 eq) of 2-{[6-(3,4-dimethoxy-phenyl)-piperidin-2-ylmethyl]-amino}-ethanol and 0.20 g (17.5 mmoles, 1.5 eq) of triphenyl phosphine in 120 mL of THF, is added 1.9 mL (12.7 mmoles, 1.1 eq) of diethyl azodicarboxylate, and the reaction is stirred at room temperature overnight. At that time there is no starting material shown on TLC. After removal of the solvent, the residue is taken in ethyl acetate and extracted with 1 N HCl solution. The acidic aqueous is basified with 1N NaOH to pH 10, and extracted with dichloromethane 3 times. The organic extracts are washed with brine, dried over Na2SO4 and concentrated to give oil product, which is purified by flash chromatography on silica gel eluted with 50:10:1 DCM: MeOH: NH4OH, to afford 6-(3,4-dimethoxy-phenyl)-octahydropyrido[1,2-a]pyrazine as a brownish stick solid (0.85 g, 27%). Analysis: 1H NMR (300 MHz, CDCl3): 6.80 (3H, m), 3.87 (3H, s), 3.84 (3H, s), 3.29 (1H, s), 2.92˜2.68 (4H, m), 2.60 (2H, m), 2.13 (1H, m), 1.82˜1.05 (8H, m). MS (LC-MS): Calculated for C16H18N2O4 302.33, found 303.39 (M+1).

Workup

  1. customAfter removal of the solvent
  2. extractionextracted with 1 N HCl solution
  3. extractionextracted with dichloromethane 3 times
  4. washThe organic extracts are washed with brine
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated
  7. customto give oil product, which
  8. customis purified by flash chromatography on silica gel
  9. washeluted with 50:10:1 DCM

Sources & evidence

ORD record
ord-854a1310fbdb40e5bb98d77d007479bf
Source dataset
uspto-grants-2006_07
Patent number
US07081458B2

Reaction notes

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