Dimethyl Sulfoxide → 4,5-Dimethylbenzene-1,2-dicarbaldehyde

Temperature

-78 °C

To a solution of oxalyl chloride 2M in dichloromethane (DCM) (26.5 ml, 53.0 mmol, 2.2 molar equivalents) cooled to −78° C. was added dropwise a solution of dimethylsulfoxide (DMSO) (7.5 ml, 105.8 mmol, 4.4 molar equivalents) in DCM (10 ml). The solution was stirred at −78° C. for 5 minutes and 4,5-dimethylbenzene-1,2-dimethanol (4.0 g, 24.1 mmol, 1.0 molar equivalent) dissolved in a mixture of DCM-DMSO (2 ml-4 ml) was added dropwise. The solution was stirred for 1 hour at −78° C. and triethylamine (20 ml) was slowly added at −78° C. The reaction mixture was stirred for 10 minutes at −78° C. and slowly warmed up to room temperature. Ice-cold water (100 ml) was added to the reaction mixture and the aqueous layer extracted with DCM (3 times 100 ml). The organic fractions were combined, dried over magnesium sulfate, filtered and concentrated in vacuum to give a brown oil. Purification by column chromatography on silicagel (eluent: hexane-ethyl acetate 8:2) gave the title compound as white needles (3.2 g, 82%). 1H NMR (300.13 MHz, CDCl3) δ(ppm) 2.42 (s, 6H) 7.73 (s, 2H) 10.50 (s, 2H).

1. additionwas added dropwise
2. stirringThe solution was stirred for 1 hour at −78° C.
3. stirringThe reaction mixture was stirred for 10 minutes at −78° C.
4. temperatureslowly warmed up to room temperature
5. extractionthe aqueous layer extracted with DCM (3 times 100 ml)
6. dry with materialdried over magnesium sulfate
7. filtrationfiltered
8. concentrationconcentrated in vacuum
9. customto give a brown oil
10. customPurification by column chromatography on silicagel (eluent: hexane-ethyl acetate 8:2)

ORD record

ord-cb7cc9638a2a480799a6715ce4aa081e

Source dataset

uspto-grants-2010_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07842942B2