[Synthesis]
1) Synthesis of 1-chloro-6-fluoroisoquinoline
6-Fluoro-2H-isoquinolin-1-one (1.3 g, 7.97 mmol) (for preparation, see PCT/GB02/00514 and WO 02/062816) was suspended in acetonitrile (20 mL), followed by the addition of phosphorus trichloride (3.7 g, 23.9 mmol). Dioxane solution (2 mL) of 4N hydrochloric acid was added dropwise. The reaction mixture was heated overnight at 50 °C with stirring. Upon completion of the reaction, the mixture was poured into saturated sodium bicarbonate solution and extracted with ethyl acetate. The organic layers were combined and concentrated to give an orange solid product (1.1 g, 78% yield). Mass spectral analysis showed [M+H]+ = 181.8. 1H NMR (300 MHz, CDCl3) δ: 7.42 (m, 2H), 8.26 (m, 3H).
21A) Synthesis of 1-chloro-6-fluoroisoquinoline
An acetonitrile (20 mL) solution of 6-fluoro-2H-isoquinolin-1-one (PCT/GB02/00514; WO 02/062816) (1.3 g, 7.97 mmol) and phosphorous triclosan (3.7 g, 23.9 mmol) was heated with a dioxane solution of 4N hydrochloric acid (2 mL) at 50 °C overnight. Upon completion of the reaction, the reaction mixture was diluted with sodium bicarbonate solution and extracted with ethyl acetate. The organic layer was concentrated to give an orange solid product (1.1 g, 78% yield). Mass spectral analysis showed [M+H]+ = 181.8. 1H NMR (400 MHz, CDCl3) δ: 7.42 (m, 2H), 8.26 (m, 3H). |