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

HRID 646786

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

Reactant 3

HCID 813641-Bromo-4-chlorobutane

HCID 84700Ethyl cyclobutanecarboxylate

HCID 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

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

Sources & evidence

ORD record: ord-c51ab133cae841cab65c35e212b069cf
Source dataset: uspto-grants-2010_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07705177B2

Linked notes

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