1,5-Dibromopentane → Butyl 1-(5-bromo-pentyl)-cyclopentanecarboxylate

HRID 661128Notes

Reaction equation

[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][C:6]1(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.BrCCCCCBr.[Li+].CC([N-]C(C)C)C>>[Br:1][CH2:2][CH2:3][CH2:4][CH2:5][CH2:6][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 81001,5-Dibromopentane

HCID 550335Butyl cyclopentanecarboxylate

HCID 2724682Lithium diisopropylamide

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

Product 1

HCID 21932025Butyl 1-(5-bromo-pentyl)-cyclopentanecarboxylate

Procedure

Compound 103f was prepared, likewise the procedure described for 103b, starting from butyl cyclopentanecarboxylate (40.2 g, 0.236 mol), 1,5-dibromopentane (64 mL, 0.45 mol) and LDA (2 M in THF/heptane/ethylbenzene, 200 mL, 0.40 mol) to give, after purification by fractional distillation under reduced pressure, 3f (49.1 g, 93% pure by GC, 61%) as a bright yellow liquid. bp: T=123° C. (p=0.001 Torr). 1H NMR: δ 4.06 (t, J=6.6 Hz, 2H), 3.38 (t, J=6.9 Hz, 2H), 2.15-2.07 (m, 2H), 1.89-1.79 (quintet, J=7.1 Hz, 2H), 1.69-1.56 (m, 8H), 1.49-1.32 (m, 6H), 1.28-1.17 (m, 2H), 0.94 (t, J=7.4 Hz, 3H). 13C NMR: δ 177.7, 64.0, 54.0, 39.0, 36.0 (2×), 33.6, 32.5, 30.7, 28.5, 25.1, 24.8 (2×), 19.1, 13.6. HRMS calcd for C15H27BrO2 (MH+): 318.1195. found: 318.1192.

Workup

customto give
customafter purification
distillationby fractional distillation under reduced pressure, 3f (49.1 g, 93% pure by GC, 61%) as a bright yellow liquid
customT=123° C. (p=0.001 Torr)

Sources & evidence

ORD record: ord-288889b73744400fa2ac96db91acc005
Source dataset: uspto-grants-2011_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08084498B2

Reaction notes

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