Hydrogen Bromide → Butanoic acid, 4-bromo-2-(methoxyimino)-3-oxo-, ethyl ester

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Reaction Steps

N.M.R. spectrum (CDCl3, δ): ppm: 4.33 (4H, q, J=8 Hz); 4.08 (3H, s); 3.95 (3H, s); 2.40 (3H, s); 1.63 (3H, s); 1.33 (6H, t, J=8 Hz). p (3) Bromine (100 g.) was dropwise added over 40 minutes under reflux to a solution of ethyl 2-methoxyiminoacetoacetate (a mixture of syn and anti isomers) (100 g.) in a mixture of carbon tetrachloride (300 ml.) and acetic acid (300 ml.). The mixture was stirred at 70° to 80° C. until the evolution of hydrogen bromide ceased. The reaction mixture was washed twice with water (300 ml.), a sodium bicarbonate aqueous solution and a saturated sodium chloride aqueous solution and dried over magnesium sulfate. The solution was treated with activated charcoal (2 g.) and concentrated under reduced pressure to give ethyl 2-methoxyimino-4-bromoacetoacetate (a mixture of syn and anti isomers) (120.8 g.).

Provenance & Evidence