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 min 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 h at −78° C. and triethylamine (20 mL) was slowly added at −78° C. The reaction mixture was stirred 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 (3×100 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 silica gel (eluent: hexane-ethyl acetate 8/2) gave the title compound as white needles (3.2 g, 82%). 1H NMR (300.13 MHz, CDCl3) (ppm) 2.42 (s, 6H) 7.73 (s, 2H) 10.50 (s, 2H).

1. additionwas added dropwise
2. stirringThe solution was stirred for 1 h at −78° C.
3. stirringThe reaction mixture was stirred 10 minutes at −78° C.
4. temperatureslowly warmed up to room temperature
5. extractionthe aqueous layer extracted with DCM (3×100 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 silica gel (eluent: hexane-ethyl acetate 8/2)

ORD record

ord-3c85b609a15f41bf9af7fe81c1ae6100

Source dataset

uspto-grants-2011_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07935960B2