Sodium Methoxide → 2-t-Butoxycarbonylmethoxyimino-2-(3-chloro-4-hydroxyphenyl)acetic acid

Participants

Reaction Steps

A mixture of 2-(3-chloro-4-hydroxyphenyl)glyoxylic acid (2.0 g.), O-t-butoxycarbonylmethylhydroxylamine (1.62 g.) and methanol (20 ml.) was adjusted to pH 5 to 6 by adding an 1N methanol solution of sodium methoxide and stirred for 3 hours at ambient temperature. The reaction mixture was concentrated to dryness under reduced pressure and the residue was dissolved in an 1N aqueous solution of sodium hydroxide to adjust to pH 7.0. The aqueous solution was washed with ether, adjusted to pH 2.0 with 10% hydrochloric acid under ice-cooling and extracted with ether. The extract was washed with water and dried over magnesium sulfate. The solution was concentrated to dryness under reduced pressure to give crystals of 2-t-butoxycarbonylmethoxyimino-2-(3-chloro-4-hydroxyphenyl)acetic acid (syn isomer) (2.6 g.), mp 116° to 118° C. (dec.).

Provenance & Evidence