Ethyl isobutyrate → HCID 11482859, compound

HRID 873293Notes

Reaction equation

HRID 873293 reaction equation
[Li+].CC([N-]C(C)C)C.[C:9]([O:14][CH2:15][CH3:16])(=[O:13])[CH:10]([CH3:12])[CH3:11].Br[CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][Br:24].[NH4+].[Cl-]>C1COCC1.CN1C(=O)N(C)CCC1>[Br:24][CH2:23][CH2:22][CH2:21][CH2:20][CH2:19][CH2:18][C:10]([CH3:12])([CH3:11])[C:9]([O:14][CH2:15][CH3:16])=[O:13]

Participants

7

Reactant 4

HCID 7342Ethyl isobutyrateHCID 123681,6-DibromohexaneHCID 25517Ammonium ChlorideHCID 2724682Lithium diisopropylamide

Product 1

HCID 11482859HCID 11482859, compoundYield 52%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 816462(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl-Solvent

Procedure

Under N2 atmosphere, a solution of LDA (2.0 M in heptane/THF/ethylbenzene, 2.94 L, 5.9 mol) was added dropwise to a stirred solution of ethyl isobutyrate (720 g, 6.2 mol) in anhydrous THF (4.7 L) at −45° C. After 1 h, 1,6-dibromohexane (2400 g, 9.8 mol) was added dropwise, followed by the addition of DMPU (320 mL). The reaction mixture was stirred for 1 h and then allowed to warm to room temperature overnight. Saturated NH4Cl solution (3 L) was added and the mixture was extracted with ethyl acetate (3×6 L). The combined organic layers were washed with brine (4.5 L), 1 M aqueous HCl (6 L), saturated NaHCO3 solution (6 L), and brine (4.5 L). The solution was dried over anhydrous MgSO4 and concentrated in vacuo. The residue was distilled under high vacuo to furnish 205i (856 g, 52%) as a light yellowish oil. Bp 95-100° C./0.2 mmHg. 1H NMR (CDCl3): δ (ppm): 4.13 (q, J=7.1, 2 μl), 3.39 (t, J=6.9, 2 H), 1.92-1.75 (m, 2H), 1.58-1.25 (m, 8H), 1.25 (t, J=7.1, 3 H), 1.12 (s, 6H). 13C NMR (CDCl3=77.52 ppm): δ (ppm): 177.62, 60.01, 42.08, 40.50, 33.63, 32.68, 29.13, 27.93, 25.00, 24.66, 14.22. HRMS (LSIMS, nba): Calcd for C12H24BrO2 (MH+): 279.0960, found: 279.0957. GC: 76.4% pure.

Workup

  1. extractionthe mixture was extracted with ethyl acetate (3×6 L)
  2. washThe combined organic layers were washed with brine (4.5 L), 1 M aqueous HCl (6 L), saturated NaHCO3 solution (6 L), and brine (4.5 L)
  3. dry with materialThe solution was dried over anhydrous MgSO4
  4. concentrationconcentrated in vacuo
  5. distillationThe residue was distilled under high vacuo

Sources & evidence

ORD record
ord-49d6912b4e084ee9b488af83e66130f6
Source dataset
uspto-grants-2015_03
Patent number
US08975300B2

Reaction notes

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