Sulfuric Acid → 3-Cyclopropyl-5-iodoisothiazole

Temperature

0 °C

To a water (1.4 mL) and ice (5.0 cc) suspension was added 3-cyclopropylisothiazol-5-amine (500 mg, 3.57 mmol) followed by concentrated sulfuric acid (1.4 mL). A solution of sodium nitrite (258 mg, 3.74 mmol) in water (5.0 mL) was added dropwise at 0° C., and the mixture was stirred at 0° C. for 1 hour. Next, a solution of potassium iodide (622 mg, 3.74 mmol) in water (3.5 mL) was added dropwise at 0° C., and the mixture was heated at 80° C. for 1 hour. Ethyl acetate at 0° C. was added and the mixture was neutralized with potassium carbonate. The organic layer was separated, dried over magnesium sulfate, concentrated under reduced pressure, and purified by silica gel chromatography (Flash 60 column) eluting with hexane/EtOAc (19:1) to give the title compound as green oil (356.5 mg, 40%). 1H NMR (500 MHz, CDCl3) δ ppm 0.92-0.98 (m, 2H), 0.98-1.04 (m, 2H), 2.13-2.20 (m, 1H), 7.06 (s, 1H).

1. temperaturethe mixture was heated at 80° C. for 1 hour
2. customThe organic layer was separated
3. dry with materialdried over magnesium sulfate
4. concentrationconcentrated under reduced pressure
5. custompurified by silica gel chromatography (Flash 60 column)
6. washeluting with hexane/EtOAc (19:1)

ORD record

ord-67cfe5c992aa4fc5b08ecfec0c6834bb

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09056873B2