Isopropyl Acetate → 4-(4,5-Dihydro-1,3-oxazol-2-yl)phenol

Participants

Reaction Steps

A 22 liter, three-necked flask was charged with 634 g (3.5 moles) of the β-hydroxyamide of part (a) and 5.2 liters of isopropyl acetate. The flask was cooled externally in a bath with tap water (10°-15° C.) and 390 ml (5.25 moles) of thionyl chloride was added to the stirred suspension over 45 minutes. A mild exotherm was apparent, but the temperature was maintained between 25° and 30° C. After stirring 2 hr at ambient temperature, the suspension was filtered and the cake washed with isopropyl acetate. After air drying for two hours, the solid was transferred to a 22 liter flask and dissolved in 1.4 liters of water. The solution was treated with saturated sodium bicarbonate solution until slightly basic. A heavy white precipitate formed during the addition. The suspension was filtered and the resulting white solid was washed with cold water and dried overnight in vacuo at 65° C. A total of 522 g (91.5%) of the 4,5-dihydro-2-(4-hydroxyphenyl)oxazole, m.p. 209°-211° C., was obtained.

Provenance & Evidence