Studies on tertiary amine oxides. LXXIV. Reactions of aromatic N-oxides with 2-phenyl-2-thiazolin-4-one in the presence of acetic anhydride.

Abstract

Quinoline 1-oxides (1a-e) readily react with 2-phenyl-2-thiazolin-4-one (2) in acetic anhydride at room temperature to afford the corresponding 5-(2-quinolyl) thiazolones (3a-e) in good yields. The reaction of 4-chloroquinoline 1-oxide (1f) gives 4-acetoxy-5-(4-chloro-2-quinolyl)-2-phenylthiazole (4). Hydrolyses of 1a-e with 48% hydrobromic acid under reflux give 2-quinolinemethanethiols as the hydrobromides (6a-e). Similar results were obtained from the reaction of isoquinoline 2-oxide (7), but pyridine 1-oxide was unreactive.