Hydrochloric Acid → Ethyl 2-amino-5-(2-pyridinecarbonyl)-4-thiazolecarboxylate

Participants

Reaction Steps

To a solution of thiourea (4.5 g) and sodium acetate (5 g) in a mixture of tetrahydrofuran (50 ml) and water (15 ml) was added ethyl 3-chloro-4-(2-pyridyl)-2,4-dioxo-butyrate hydrochloride (5.6 g). After the mixture was stirred at 45° C. to 50° C. for 2 hours, water (50 ml) was added thereto. The resulting mixture was acidified to pH 1.0 with 10% hydrochloric acid. The precipitate was collected by filtration. The precipitate was added to a mixture of water and ethyl acetate, and adjusted to pH 6.0 with 10% potassium carbonate. The separated ethyl acetate layer was washed with brine, dried over magnesium sulfate, and evaporated in vacuo. The residue was recrystallized from a mixture of ethyl acetate and tetrahydrofuran to give ethyl 2-amino-5-(2-pyridinecarbonyl)-4-thiazolecarboxylate (1.1 g).

Provenance & Evidence