Water → 3-(2-Pyrazinyloxy)-benzaldehyde dimethyl acetal

HRID 1740440Notes

Reaction equation

[CH3:1][O:2][CH:3]([O:11][CH3:12])[C:4]1[CH:9]=[CH:8][CH:7]=[C:6]([OH:10])[CH:5]=1.CC(C)([O-])C.[K+].Cl[C:20]1[CH:25]=[N:24][CH:23]=[CH:22][N:21]=1.O>CN(C)C=O>[CH3:1][O:2][CH:3]([O:11][CH3:12])[C:4]1[CH:9]=[CH:8][CH:7]=[C:6]([O:10][C:20]2[CH:25]=[N:24][CH:23]=[CH:22][N:21]=2)[CH:5]=1

Participants

Conditions

Temperature: 60 °C

Procedure

A solution of 168 mg of 3-hydroxybenzaldehyde dimethyl acetal in 10 ml of anyhydrous dimethylformamide was stirred under nitrogen and 220 mg of potassium tert-butoxide were added. The mixture was heated at 60° C. for 1 hour, then cooled to room temperature and 115 mg of 2-chloropyrazine were added in portions. The mixture was then heated at 160° C. for 18 hours. After cooling 15 ml of water were added and the product was extracted with 50 ml of ethyl acetate. The extract was washed with 25 ml of 1M sodium hydroxide solution and 25 ml of brine and then dried over anhydrous magnesium sulphate. After filtration and evaporation of the filtrate the residual yellow oil was purified by column chromatography on silica gel using ethyl acetate/hexane (1:1) for the elution to give 3-(2-pyrazinyloxy)-benzaldehyde dimethyl acetal as a yellow oil.

Workup

temperaturecooled to room temperature
temperatureThe mixture was then heated at 160° C. for 18 hours
additionwere added
extractionthe product was extracted with 50 ml of ethyl acetate
washThe extract was washed with 25 ml of 1M sodium hydroxide solution and 25 ml of brine
dry with materialdried over anhydrous magnesium sulphate
filtrationAfter filtration and evaporation of the filtrate the residual yellow oil
customwas purified by column chromatography on silica gel
washfor the elution

Sources & evidence

ORD record: ord-7533f8b0bc114c87a50d212b5b25431f
Source dataset: uspto-grants-1999_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05969139

Reaction notes

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