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

HRID 873255Notes

Reaction equation

HRID 873255 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

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-877f8da0c755470c9cde86e5ae1da1f2
Source dataset
uspto-grants-2015_03
Patent number
US08975300B2

Reaction notes

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