Hydrochloric Acid → 2-Chloro-1,3-thiazole-4-carboxylic acid

Temperature

0 °C

To a solution of 2.84 g (19.7 mmol) of 2-aminothiazole-4-carboxylic acid in 30 ml of 1,4-dioxane was added 50 ml of concentrated hydrochloric acid, followed by cooling to 0° C., and 10 ml of an aqueous solution of 2.04 g (29.6 mmol) of sodium nitrite was added charged dropwise thereto at 0° C. to 5° C. The reaction liquid was stirred at 0° C. for 2 hours, and then 2.93 g (29.6 mmol) of copper chloride was charged in separate portions thereto. The reaction liquid was returned to room temperature, followed by stirring for 8 hours. To the reaction liquid were added water and ethyl acetate, followed by extraction with ethyl acetate four times. The organic layer was washed with saturated brine, and then dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure to prepare 1.77 g (yield 55%) of a target compound.

1. additioncharged dropwise
2. customat 0° C. to 5° C
3. customThe reaction liquid
4. customThe reaction liquid
5. customwas returned to room temperature
6. stirringby stirring for 8 hours
7. customTo the reaction liquid
8. extractionfollowed by extraction with ethyl acetate four times
9. washThe organic layer was washed with saturated brine
10. dry with materialdried over anhydrous magnesium sulfate
11. customThe solvent was evaporated under reduced pressure

ORD record

ord-e2ff88eb760a41e29dc6f9fa5d883660

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09237745B2