Isoamyl Nitrite → Methyl 2-hydroxyimino-2-(isothiazol-4-yl)acetate

Participants

Reaction Steps

A solution of sodium (1.01 g.) in absolute methanol (10 ml.) was dropwise added over 15 minutes with stirring and ice-cooling to a solution of methyl 2-(isothiazol-4-yl)acetate (6.30 g.) and isopentyl nitrite (10.6 g.) in absolute methanol (63 ml.). The mixture was stirred for 30 minutes at the same temperature and for 3 hours at ambient temperature. The reaction mixture was concentrated and the residue was poured into a mixture of ethyl acetate (50 ml.) and water (50 ml.). The aqueous layer was separated and the ethyl acetate layer was extracted twice with 1 N aqueous solution of sodium hydroxide (20 ml. and 10 ml.). The extracts and the aqueous layer separated above were combined, adjusted to pH 1 with 10% hydrochloric acid and extracted twice with ethyl acetate (70 ml. and 50 ml.). The extracts were washed with a 5% aqueous solution of sodium bicarbonate and a saturated aqueous solution of sodium chloride and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to give methyl 2-hydroxyimino-2-(isothiazol-4-yl)acetate (anti isomer) (4.55 g.), mp 110° to 112° C.

Provenance & Evidence