Thionyl Chloride → 4-Bromothiazole-2-carbohydrazide

To a solution of 4-bromothiazole-2-carboxylic acid (2.0 g, 9.8 mmol) in methanol (10 mL) was added thionyl chloride (710 μL, 9.8 mmol) and the mixture was refluxed for 3 hours. The solvent was removed under reduced pressure, and the residue was suspended in ethanol (10 mL). To this suspension was added hydrazine hydrate (2.4 mL, 49 mmol), and the reaction was heated to reflux for 90 minutes. The solvent was removed under reduced pressure, and the residue suspended in acetonitrile, filtered, and the solids were washed with acetonitrile, diethyl ether, and dried under vacuum to afford 1.7 g (77%) of 4-bromothiazole-2-carbohydrazide as a yellow solid. M+1=222.1

1. temperaturethe mixture was refluxed for 3 hours
2. customThe solvent was removed under reduced pressure
3. temperaturethe reaction was heated
4. temperatureto reflux for 90 minutes
5. customThe solvent was removed under reduced pressure
6. filtrationfiltered
7. washthe solids were washed with acetonitrile, diethyl ether
8. customdried under vacuum

ORD record

ord-0ef677d8434c454d99fad4f728dd63e6

Source dataset

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08440665B2