Hydrochloric Acid → 2-(2-Formamido-5-chlorothiazol-4-yl)-2-propargyloxyiminoacetic acid

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Reaction Steps

A solution of chlorine (3.2 g) in acetic acid (44 ml) was dropwise added to a solution of 2-(2-formamidothiazol-4-yl)-2-(propargyloxyimino)acetic acid (syn isomer) (10 g) in chloroform (250 ml) at 0° C., and the mixture was stirred for 30 minutes at same temperature. The resultant solution was added to a saturated aqueous solution of sodium bicarbonate and adjusted to pH 7.5 with 10% aqueous solution of sodium hydroxide. The separated aqueous layer was adjusted to pH 2.0 with conc. hydrochloric acid and extracted with ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and evaporated in vacuo. The residue was washed with diisopropyl ether and collected by filtration to give 2-(2-formamido-5-chlorothiazol-4-yl)-2-propargyloxyiminoacetic acid (syn isomer) (5.96 g), mp 161° to 162° C. (dec.).

Provenance & Evidence