1step/89% 2,5-dimethoxybenzaldehyde from p-dimethoxybenzene

vistaril · Fri Sep 23, 2005 9:28 am

Synlett 2004, 9, 1575

Summary:

10 mmol p-dimethoxybenzene, 3 g (100 mmol) paraformaldehyde, 0.25 mg (0.0025 mmol) H2SO4 and 4.54 g (20 mmol) DDQ were stirred in 10 mL MeCN for 5 h at 80 °C. The reaction mixtures were then cooled and the precipitate containing the DDHQ product was filtered and washed twice with EtOAc. The filtrate containing the aryl aldehyde products was purified by flash chromatography.

89% yield, 99% pure.

The 2,3-dichloro-5,6-dicyanohydroquinone (DDHQ) formed in the reaction can be recovered and re-oxidized to DDQ with nitric acid.

biobrew · Fri Sep 23, 2005 10:16 am

anime · Sat Oct 01, 2005 10:23 pm

DDQ is veery expensive. This synth was back at the hive.