Sodium Bicarbonate → Ethyl 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetate

Beteiligte Stoffe

Reaktionsschritte

Ethyl 2-methoxyimino-4-chloroacetoacetate (syn isomer) (50 g.) was added over 3 minutes with stirring at ambient temperature to a solution of thiourea (18.4 g.) and sodium acetate (19.8 g.) in a mixture of methanol (250 ml.) and water (250 ml.). After stirring for 35 minutes at 40° to 45° C., the reaction mixture was cooled with ice and adjusted to pH 6.3 with a saturated aqueous solution of sodium bicarbonate. After stirring for 30 minutes at the same temperature, precipitates were collected by filtration, washed with water (200 ml.) and then with diisopropyl ether (100 ml.), and dried to give colorless crystals of ethyl 2-methoxyimino-2-(2-amino-1,3-thiazol-4-yl)acetate (syn isomer) (37.8 g.), m.p. 161° to 162° C.

Herkunft & Nachweise