p-Toluenesulfonic acid monohydrate → HCID 53886128, compound

Participants

Reaction Steps

The dihydro-4-[(3,5-di-tert-butyl-4-hydroxyphenyl)hydroxymethyl]-2-ethyl-2H-1,2-oxazin-3(4H)-one (15 g, 41 mmol) obtained according to Step B was added to 100 ml of benzene and 0.4 g of p-toluenesulfonic acid monohydrate and refluxed for 13 hours. The mixture was concentrated to a solid, taken up in 150 ml of methylene chloride, washed with dilute sodium bicarbonate solution, dried over anhydrous magnesium sulfate and concentrated to a brown solid (14.1 g) which was recrystallized from acetone to yield 6.4 g of crystalline dihydro-4-(3,5-di-tert-butyl-4-hydroxybenzylidene)-2-ethyl-2H-1,2-oxazin-3(4H)-one having a melting point of 166°-167° C.

Provenance & Evidence