Hydrochloric Acid → HCID 11150543, compound

Participants

Reaction Conditions

Reaction Steps

Into a solution of 4-trifluoromethyl benzaldehyde (400.0 g, 2.3 mol) and 2,3-butanedione monoxime (212 g, 2.055 mol) in 800 mL of glacial acetic acid at 2–5° C., hydrogenchloride gas (250 g) is slowly bubbled for 1.5 hours. The mixture is stirred at the same temperature for 1 hour further. 3.75 L of t-butyl methyl ether are added while maintaining the temperature between 5–25° C. (first 400 mL addition is exothermic). The resulting suspension is stirred for 30 minutes, then cooled to 10° C. and the solids are collected by filtration. The filter cake is washed with 500 mL of t-butylmethyl ether, and dried at 55–60° C. (20 mbar) for 18 hours to afford 550 g (91% yield) of 4,5-dimethyl-2-[4-(trifluoromethyl)phenyl]-oxazole 3-oxide, hydrochloride salt: m.p. 182–184° C. (with decomposition).

Provenance & Evidence