Benzene, 1-bromo-3,5-dimethyl- → HCID 15458520, compound

HRID 1602346Notes

Reaction equation

Br[C:2]1[CH:3]=[C:4]([CH3:9])[CH:5]=[C:6]([CH3:8])[CH:7]=1.C([Li])CCC.[Cl:15][CH2:16][CH2:17][CH2:18][C:19](N(OC)C)=[O:20]>O1CCCC1>[CH3:9][C:4]1[CH:3]=[C:2]([C:19]([CH2:18][CH2:17][CH2:16][Cl:15])=[O:20])[CH:7]=[C:6]([CH3:8])[CH:5]=1

Participants

Conditions

Temperature: -78 °C

Procedure

A solution of 10.2 mL (13.9 g; 72 mmol) 5-bromo-m-xylene in 200 mL of anhydrous tetrahydrofuran was stirred under nitrogen at -78° C. as 35.8 mL (84 mmol) of 2.5 M n-butyllithium in tetrahydrofuran was added dropwise. After 15 minutes at -78° C., a solution of 10.0 g (60 mmol) of 4-chloro-N-methoxy-N-methylbutyramide in 30 mL of anhydrous tetrahydrofuran was added dropwise over 25-30 minutes. The resulting solution was maintained at -78° C. for 45 minutes and then warmed briefly to room temperature. The reaction was quenched by addition of 40 mL of 2 N hydrochloric acid and then partitioned between ethyl acetate and water. The organic phase was washed with saturated aqueous sodium bicarbonate solution and then saturated aqueous sodium chloride solution. The organic solution was dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography of the residue afforded 8.91 g (70%) of an oil, which had satisfactory purity by 1H NMR (CDCl3).

Workup

additionwas added dropwise
temperaturewarmed briefly to room temperature
customThe reaction was quenched by addition of 40 mL of 2 N hydrochloric acid
custompartitioned between ethyl acetate and water
washThe organic phase was washed with saturated aqueous sodium bicarbonate solution
dry with materialThe organic solution was dried over sodium sulfate
filtrationfiltered
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-13311a8095b44f09b87c044741951e60
Source dataset: uspto-grants-1999_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05981550

Reaction notes

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