Acetone → 2-Bromo-1-thiophen-3-yl-butan-1-one

HRID 2266170

Reaction equation

CC[Mg+].[Br-].C[C:6]([OH:9])(C)C.[CH3:10][C:11]([CH3:13])=[O:12].[Br:14][CH:15]([CH2:23][CH3:24])[C:16]([C:18]1[CH:22]=[CH:21][S:20][CH:19]=1)=[O:17]>C1C=CC=CC=1>[Br:14][CH:15]([CH2:23][CH3:24])[C:16]([C:18]1[CH:22]=[CH:21][S:20][CH:19]=1)=[O:17].[S:20]1[CH:21]=[CH:22][C:18]([CH:16]([CH2:15][CH3:23])[C:6](=[O:9])[CH2:10][C:11](=[O:12])[CH3:13])=[CH:19]1

Participants

Conditions

Temperature: 0 °C

Procedure

EtMgBr (6.69 ml, 13 mmol, 2 M in ethyl ether) in benzene (10 ml) was cooled to zero degrees C, and tBuOH (1.28 ml, 13 mmol) was slowly added. The reaction mixture was stirred at zero degrees C for 5 minutes, then acetone (530 ul, 7 mmol) was added, followed by a solution of 2-Bromo-1-thiophen-3-yl-butan-1-one (1.3 g, 6 mmol) in 3 ml benzene via cannula. The reaction mixture was heated to reflux for 1 hour, and acetone (250 ul) was added. The reaction mixture was heated 2 hours more at reflux. The reaction was cooled, quenched with 1 N HCl (10 ml), extracted three times with diethyl ether, washed brine, and dried over magnesium sulfate. The solvent was removed in vacuo and the residue chromatographed (5% ethyl acetate/hexanes) to give 247 mg of 2-Bromo-1-thiophen-3-yl-butan-1-one starting material and 520 mg of 5-Thiophen-3-yl-heptane-2,4-dione, 44% .

Workup

temperatureThe reaction mixture was heated
temperatureto reflux for 1 hour
temperatureThe reaction mixture was heated 2 hours more
temperatureat reflux
temperatureThe reaction was cooled
customquenched with 1 N HCl (10 ml)
extractionextracted three times with diethyl ether
washwashed brine
dry with materialdried over magnesium sulfate
customThe solvent was removed in vacuo
customthe residue chromatographed (5% ethyl acetate/hexanes)

Sources & evidence

ORD record: ord-ccbfb89603834a1a90ac0f1bafeaa854
Source dataset: uspto-grants-2010_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07858632B2

Linked notes

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