p-Toluenesulfonic acid → 7-Bromo-6-iodo-1,2-benzothiazole

A mixture of 3-bromo-2-tert-butylsulfanyl-4-iodo-benzaldehyde oxime (1.0 g, 2.4 mmol) and p-toluenesulfonic acid (0.19 g, 1 mmol) in n-butanol (50 mL) were heated to reflux for 16 h. The reaction mixture was cooled and concentrated. Water (40 mL) was added to the residue, followed by saturated sodium bicarbonate solution. The mixture was extracted with dichloromethane (3×40 mL). The combined organic fractions were washed with water, dried over anhydrous sodium sulfate, filtered, and concentrated. Purification of the residue by column chromatography (5% ethyl acetate:hexanes) afforded 0.23 g (28%) of the title compound as a solid. 1H NMR (300 MHz, CDCl3): δ 7.36 (d, J=7.8 Hz, 1H), 7.69 (d, J=7.8 Hz, 1H), 8.99 (s, 1H).

1. temperaturewere heated
2. temperatureto reflux for 16 h
3. temperatureThe reaction mixture was cooled
4. concentrationconcentrated
5. additionWater (40 mL) was added to the residue
6. extractionThe mixture was extracted with dichloromethane (3×40 mL)
7. washThe combined organic fractions were washed with water
8. dry with materialdried over anhydrous sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated
11. customPurification of the residue by column chromatography (5% ethyl acetate:hexanes)

ORD record

ord-92433c0a477f4f4d866ac3d2f72a824f

Source dataset

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08378104B2