Hydrochloric Acid → HCID 178494318, compound

Temperature

2.5 °C

A solution of bromine (0.405 ml) in dichloromethane (8 ml) at 0-5° C. was added dropwise to a mixture of 3-methoxypyrazole (775 mg) and sodium carbonate (1.67 mg) in dichloromethane (16 ml) under argon over a period of 10 minutes. The resulting suspension was stirred at 0-5° C. for 30 minutes. Aqueous sodium thiosulfate (2.37 ml, 0.1N) at 0-5° C. was added to the stirred suspension and the resulting mixture was stirred at 0-5° C. for 1 hour. The reaction mixture was allowed to warm to room temperature and quenched with water. The phases were separated. The aqueous phase was extracted with dichloromethane. The combined organic phases were washed with water, dried over magnesium sulfate and concentrated to afford a brown oil. Hydrogen chloride (4N in dioxane) (1.975 ml) was added to this brown oil. The mixture was diluted in dioxane and triturated. The resulting precipitate was collected by filtration, washed with dioxane and diethyl ether and dried to a constant weight to afford 4-bromo-3-methoxy-1H-pyrazole, hydrochloride salt (1 g) as a solid, which was used without further purification. NMR Spectrum: (DMSOd6) 3.82 (s, 3H), 7.78 (s, 1H), 7.99 (bs, 2H)

1. stirringthe resulting mixture was stirred at 0-5° C. for 1 hour
2. temperatureto warm to room temperature
3. customquenched with water
4. customThe phases were separated
5. extractionThe aqueous phase was extracted with dichloromethane
6. washThe combined organic phases were washed with water
7. dry with materialdried over magnesium sulfate
8. concentrationconcentrated
9. customto afford a brown oil
10. customtriturated
11. filtrationThe resulting precipitate was collected by filtration
12. washwashed with dioxane and diethyl ether
13. customdried to a constant weight

ORD record

ord-356d1ebe93574314bffd632010710b23

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08017611B2