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

HRID 1604084Notes

Reaction equation

HRID 1604084 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; R=0.43 (7:1 hexanes/ethyl acetate) 1H NMR (300.15 MHz) δ 1.19 (d, J=5.4 Hz, 3 H), 2.25 (5, 3 H), 3.39 (q, J=6.9 Hz, 1 H), 2.57 (AB quartet, δA =3. 33, δB =3. JAS=13.8 Hz, 4 H), 7.19-7.43 (m, 10 H); 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-a84e7bdaaaac4496afdc6b9e22f3a4a9
Source dataset
uspto-grants-1999_11
Patent number
US05990341

Reaction notes

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