1,5-Benzothiazepin-4(5H)-one, 7-fluoro-2,3-dihydro- synthesis

Yield:313369-11-8 24%

Reaction Conditions:

with sulfuric acid in acetic acid;

Steps:

4.C Step C

Step C 6-fluoro-2,3-dihydro-4H-1-benzothiopyran-4-one (100 mg, 0.54 mmol) was dissolved in acetic acid (0.5 mL, 1.1 eq), sodium azide (71.2 mg, 1.1 mmol) was added and mixture was heated to 50° C. Sulfuric acid (0.13 mL, 4.3 eq) was added slowly and stirred at 50° C. for 1.5 hours. Ice chips (150 mg) were added and a green solid precipitated, this was filtered, washed with water and dried to give 7-fluoro-2,3-dihydro-1,5-benzothiazepin-4(5H)-one (80 mg, 24%). ¹H NMR (CDCl₃, 300 MHz): δ 7.77 (s-broad, 1H), 7.69 (t, 1H, J=7.3 Hz), 6.94-6.82 (m, 2H), 3.42 (t, 2H, J=7 Hz), 2.63 (t, 2H, J=6.7 Hz) ppm.

References:

US2004/220178,2004,A1