Triethylamine → 3-(Dibenzylamino)butan-2-one

HRID 1082003Notes

Reaction equation

HRID 1082003 reaction equation
[CH2:1](N(CC)CC)C.[CH2:8]([N:15]([CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[C@H:16]([C:18]([OH:20])=O)[CH3:17])[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.C(=O)=O.C(Cl)(Cl)(Cl)Cl.CC(C)(C)C(Cl)=O.C[Mg]Cl>O1CCCC1>[CH3:1][C:18]([CH:16]([N:15]([CH2:8][C:9]1[CH:10]=[CH:11][CH:12]=[CH:13][CH:14]=1)[CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[CH3:17])=[O:20]

Participants

7

Reactant 5

HCID 8471TriethylamineHCID 62493Pivaloyl chlorideHCID 11818061HCID 11818061, compoundHCID 86602444Carbontetrachloride dry-iceHCID 178418332HCID 178418332, compound

Product 1

HCID 124402103-(Dibenzylamino)butan-2-oneYield 65%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Triethylamine (8.85 mmol, 1.24 mL) was added under an argon atmosphere to a stirred solution of N,N-dibenzylalanine (8.85 mmol, 2.38 g) in tetrahydrofuran (THF) (53.0 mL) at -30° C. (dry ice/CCl4 bath). Trimethyl acetyl chloride (8.85 mmol, 1.42 mL) was then added dropwise via syringe and the turbid solution was allowed to stir at -30° C. for 30 minutes before dropwise addition of a solution of methylmagnesium chloride in THF (3.0M, 1.07 eq., 9.5 mmol, 3.23 mL) over 10 minutes. The solution was stirred for 45 minutes and then quenched with saturated solution of NH4Cl (5.0 mL). The solution was extracted with Et2O, the organic extracts washed with brine, dried over MgSO4, and filtered. The solvent was evaporated in vacuo and the residue was subjected to flash column chromatography on silica gel with 8:1 hexanes/ethyl acetate to isolate a pure product in 65% yield. Colorless oil; Rf =0.43 (7:1 hexanes/ethyl acetate) 1H NMR (300.15 MHz) δ1.19 (d, J=5.4 Hz, 3H), 2.25 (5, 3H), 3.39 (q, J=6.9 Hz, 1H), 2.57 (AB quartet, δA =3.33, δB =3. JAS=13.8 Hz, 4H), 7.19-7.43 (m, 10H); 13C NMR (75.5 MHz 7.1, 27.7, 54.6, 62.9, 27.2, 128.5, 128.8, 139.3, 210.8; IR (Neat) 1710 cm-1 ; MS (low resolution) m/e 268 M+H 22%), 224 (MeCHNBn2, 100%); HRMS for C18H22NO: 268-1709 (calc'd 268-1676); Anal: calc'd for C18H21NO: C 80.68, H 7.92, N 5.24; Found: C 80.79, H 7.95, N 5.17.

Workup

  1. customquenched with saturated solution of NH4Cl (5.0 mL)
  2. extractionThe solution was extracted with Et2O
  3. washthe organic extracts washed with brine
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. customThe solvent was evaporated in vacuo
  7. customto isolate a pure product in 65% yield

Sources & evidence

ORD record
ord-376305338e8745ae8b021c0a8f51d6b1
Source dataset
uspto-grants-1996_12
Patent number
US05587514

Reaction notes

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