Bromide ion → 1-[4-(4-Chlorophenyl)-cyclohexyl]pent-4-en-1-one

HRID 579597Notes

Reaction equation

CON(C)[C:4]([CH:6]1[CH2:11][CH2:10][CH:9]([C:12]2[CH:17]=[CH:16][C:15]([Cl:18])=[CH:14][CH:13]=2)[CH2:8][CH2:7]1)=[O:5].[Br-].O.Cl>O1CCCC1>[Cl:18][C:15]1[CH:16]=[CH:17][C:12]([CH:9]2[CH2:10][CH2:11][CH:6]([C:4](=[O:5])[CH2:8][CH2:7][CH:6]=[CH2:4])[CH2:7][CH2:8]2)=[CH:13][CH:14]=1

Participants

Conditions

Temperature: 0 °C

Procedure

While under a nitrogen atmosphere, a solution of 4-(4-chlorophenyl)-cyclohexanecarboxylic acid, methoxy-methyl amide (1.8 g, 6.39 mmol), in tetrahydrofuran (10 mL) was cooled to 0° C. and treated with 4-butenylmagnesiun bromide (0.5 M in THF, 31.95 mL, 15.98 mmol) dropwise. After stirring for 1 hour at 0° C. the reaction mixture was warmed to room temperature overnight, poured into water, acidified to pH 3-4 with 1 N hydrochloric acid and extracted with ethyl acetate (3×). The combined organic phase was washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. Purification by flash column chromatography (silica gel, 0-20% ethyl acetate in heptane) gave 1-[4-(4-chlorophenyl)-cyclohexyl]pent-4-en-1-one as a colorless oil (1.62 g, 92%); 1H NMR (CDCl3, 300 MHz) δ 7.26 (m, 2H), 7.12 (d, J=8 Hz, 2H), 5.81 (m, 1H), 5.02 (m, 2H), 2.58 (t, J=7 Hz, 2H), 2.44 (m, 2H), 2.34 (m, 2H), 1.99 (m, 4H) and 1.47 (m, 4H).

Workup

temperaturewas warmed to room temperature overnight
extractionextracted with ethyl acetate (3×)
washThe combined organic phase was washed with saturated aqueous sodium chloride
dry with materialdried over anhydrous magnesium sulfate
filtrationfiltered
concentrationconcentrated in vacuo
customPurification by flash column chromatography (silica gel, 0-20% ethyl acetate in heptane)

Sources & evidence

ORD record: ord-9ef420bd88bc4484b7eb23babe53ceb8
Source dataset: uspto-grants-2015_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09040703B2

Reaction notes

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