1-Bromo-4-chlorobutane → Ethyl 1-(4-chlorobutyl)-1-cyclobutanecarboxylate

HRID 968996Notes

Reaction equation

HRID 968996 reaction equation
[Li+].CC([N-]C(C)C)C.[CH:9]1([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH2:12][CH2:11][CH2:10]1.Br[CH2:19][CH2:20][CH2:21][CH2:22][Cl:23]>>[Cl:23][CH2:22][CH2:21][CH2:20][CH2:19][C:9]1([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH2:12][CH2:11][CH2:10]1

Participants

4

Reactant 3

HCID 813641-Bromo-4-chlorobutaneHCID 84700Ethyl cyclobutanecarboxylateHCID 2724682Lithium diisopropylamide

Product 1

HCID 21932003Ethyl 1-(4-chlorobutyl)-1-cyclobutanecarboxylate

Conditions

Temperature
0 °C

Procedure

Compound 104b was prepared, likewise the procedure described for 104c, starting from LDA (prepared from BuLi (2.5M in hexanes, 52.8 mL, 132 mmol) and iPr2NH (18.52 mL, 132 mmol, distilled from NaOH)), ethyl 1-cyclobutanecarboxylate (Török, B. et al. J. Chem. Soc. Perkin Trans. 1, 1993, 7, 801-804) (14.05 g, 110 mmol) (the resulting mixture was allowed to warm to 0° C. and cooled again to −60° C.) and 1-bromo-4-chlorobutane (19.1 mL, 165 mmol) to give, after purification by fractional distillation under reduced pressure, 104b (20.53 g, 86%) as a thin, colorless oil. bp: T=64-71° C. (p=0.001 Torr). 1H NMR: δ 4.13 (q, J=7.1 Hz, 2H), 3.51 (t, J=6.8 Hz, 2H), 2.50-2.32 (m, 2H), 1.96-1.70 (m, 8H), 1.40-1.20 (m, 2H), 1.26 (t, J=7.2 Hz, 3H). 13C NMR: δ 176.6, 60.3, 47.6, 44.8, 37.3, 32.8, 30.1 (2×), 22.4, 15.8, 14.4.

Workup

  1. customto give
  2. customafter purification
  3. distillationby fractional distillation under reduced pressure, 104b (20.53 g, 86%) as a thin, colorless oil
  4. customT=64-71° C. (p=0.001 Torr)

Sources & evidence

ORD record
ord-66bc6618d1304ce09721ea708ee5b158
Source dataset
uspto-grants-2007_12
Patent number
US07304093B2

Reaction notes

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