Hydrochloric Acid → 2-(2-Cyclohexen-1-yl)oxyimino-2-(2-aminothiazol-4-yl)acetic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of N-(2-cyclohexen-1-yl)oxyphthalimide (17.6 g) and hydrazine hydrate (7.2 g) in ethanol (180 ml) was stirred for 1.5 hours at 60° C. After the addition of water (100 ml) and conc.hydrochloric acid (20 ml) to the reaction mixture, the resulting mixture was filtered and the filtrate was evaporated. The remaining mixture was filtered to give the filtrate containing (2-cyclohexen-1-yl)oxyamine hydrochloride (Filtrate A). To a suspension of 2-(2-formamidothiazol-4-yl)glyoxylic acid (10.0 g) in water (50 ml) was added a solution of sodium hydroxide (4.4 g) in water (50 ml). The resulting mixture was stirred for 2.5 hours at room temperature and the mixture containing 2-(2-aminothiazol-4-yl)glyoxylic acid was adjusted to pH 7.0 with 10% hydrochloric acid and then thereto was added the above obtained Filtrate A. The mixture was stirred for 2 hours at room temperature. The reaction mixture was adjusted to pH 7.5 with 4N aqueous solution of sodium hydroxide and then evaporated. The residue was washed with ethyl acetate and then adjusted to pH 2.0 with 10% hydrochloric acid. The precipitates were collected by filtration, washed with water, dried over phosphorus pentoxide to give 2-(2-cyclohexen-1-yl)oxyimino-2-(2-aminothiazol-4-yl)acetic acid (syn isomer)(2.0 g).

Provenance & Evidence