Thiourea → Methyl 4-acetyl-2-amino-1,3-thiazole-5-carboxylate

Participants

Reaction Steps

A solution of 4.37 g (19 mmol) methyl 2-chloro-4,4-dimethoxy-3-oxopentanoate (Intermediate 17) and 1.8 g (24 mmol) thiourea in 50 ml EtOH was heated at reflux for 3 h. Solvent was removed and the residue was dissolved in 1:1 acetone-5N HCl and the solution was heated at reflux for 4 h. Acetone was removed and the aqueous residue was neutralized with 50% NaOH and then basified with aqueous Na2CO3. Precipitated solids were filtered, washed with water and dried in vacuum. NMR: 2.4 (s, 3H), 3.7 (s, 3H), 8.0 (s, 2H).

Provenance & Evidence