Ethylene Glycol → Benzyl oximino-acetoacetate ethylene ketal

Participants

Reaction Steps

In a two liter flask fitted with a Dean Stark water separator and a condenser were placed in 186.5 g. (0.85 mole) of benzyl oximino-acetoacetate [1.1], 62 g. (1 mole) of ethylene glycol, 800 ml. of benzene (reagent grade) and 2 g. (10.5 mmole) of p-toluenesulfonic acid monohydrate. The reaction mixture was boiled at reflux until 15 ml. of water was removed (3 hours). The benzene solution was washed once with saturated sodium bicarbonate solution and once with brine. After drying over anhydrous sodium sulfate, the benzene solution was evaporated, leaving 212 g. (94% yield) of benzyl oximino-acetoacetate ethylene ketal [2.1] as a light yellow oil! Its NMR spectrum was consistent with the assigned structure. Generally, the product was used as such in subsequent reactions but one of the isomers can be crystallized2 from toluene-petroleum either (b.p. 30°-60° C.); m.p. 52° C.

Provenance & Evidence