Formaldehyde → Benzaldehyde, 2-hydroxy-5-methyl-

Participants

Reaction Steps

p-Cresol (100 g) in dry THF (100 ml) was added over 30 minutes dropwise to a mechanically stirred, freshly prepared solution of ethyl magnesium bromide [magnesium (25.0 g) and bromoethane (75 ml)] in THF (500 ml) under nitrogen at a rate which maintained a slow reflux. After a further 30 mins toluene (1.21) was added, followed by 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidone (125 ml), and paraformaldehyde (70 g). The mixture was then heated at reflux for 16 h. The mixture was concentrated by distillation and aqueous hydrochloric acid (2M, 600 ml) then added. Water (600 ml) was added and the mixture filtered through "hyflo", dried and concentrated in vacuo to give a brown oil. The oil was steam distilled and the product extracted from the distillate with ether (1 liter). The organic extract was dried and concentrated in vacuo to give a pale yellow slurry which was triturated with ether at -10° C. to give the title compound as colourless needles, (131.4 g).

Provenance & Evidence