1,4-Dibromobutane → Butyl 1-(4-bromo-butyl)-cyclopentanecarboxylate

HRID 646782Notes

Reaction equation

[Br:1][CH2:2][CH2:3][CH2:4][CH2:5]C1(C(OC(C)(C)C)=O)CC1.[CH:16]1([C:21]([O:23][CH2:24][CH2:25][CH2:26][CH3:27])=[O:22])[CH2:20][CH2:19][CH2:18][CH2:17]1.BrCCCCBr.[Li+].CC([N-]C(C)C)C>>[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][C:16]1([C:21]([O:23][CH2:24][CH2:25][CH2:26][CH3:27])=[O:22])[CH2:20][CH2:19][CH2:18][CH2:17]1

Participants

Reactant 4

HCID 80561,4-Dibromobutane

HCID 550335Butyl cyclopentanecarboxylate

HCID 2724682Lithium diisopropylamide

HCID 21932036Tert-Butyl 1-(4-bromobutyl)cyclopropanecarboxylate

Product 1

HCID 21932063Butyl 1-(4-bromo-butyl)-cyclopentanecarboxylate

Procedure

Compound 103c was prepared, likewise the procedure described for 103b, starting from butyl cyclopentanecarboxylate (Payne, G. B. et al. J. Org. Chem., 1957, 22, 1680-1682) (80.0 g, 0.42 mol), 1,4-dibromobutane (183.3 g, 0.84 mol) and LDA (2 M in THF/heptane/ethylbenzene, 250 mL, 0.50 mol) to give, after purification by fractional distillation under reduced pressure, 103c (62.8 g, 49%) as a light yellow liquid. bp: T=116-117° C. (p=0.040-0.051 Torr). 1H NMR: δ 4.07 (t, J=6.6 Hz, 2H), 3.38 (t, J=6.8 Hz, 2H), 2.16-2.10 (m, 2H), 1.83 (quintet, J=7.1 Hz, 2H), 1.65-1.59 (m, 8H), 1.50-1.31 (m, 6H), 0.94 (t, J=7.2 Hz, 3H). 13C NMR: δ 177.6, 64.1, 53.9, 38.2, 36.0 (2×), 33.3, 33.0, 30.6, 24.8 (2×), 24.6, 19.1, 13.6. HRMS calcd for C14H25BrO2 (M+): 304.1038, found: 304.1042.

Workup

customto give
customafter purification
distillationby fractional distillation under reduced pressure, 103c (62.8 g, 49%) as a light yellow liquid
customT=116-117° C. (p=0.040-0.051 Torr)

Sources & evidence

ORD record: ord-f92c44b8ce8a4668ab8e5f6d09c83dba
Source dataset: uspto-grants-2010_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07705177B2

Reaction notes

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