Hydrochloric Acid → 3-Methoxy-1,2-oxazole-5-carboxylic acid

To a solution of methyl 3-hydroxyisoxazole-5-carboxylate (958 mg, 6.69 mmol) in DMF (10 ml) was added potassium carbonate (935 mg, 6.76 mmol) at −5° C. Then dimethyl sulfate (644 μL, 6.76 mmol) was added slowly. The reaction mixture was allowed to warm to room temperature and was stirred over night. Then 2N NaOH (5.02 mL, 10.0 mmol) was added and the mixture was stirred for 4 h. After slow addition of 2N HCl (6.69 mL, 13.4 mmol), the mixture was extracted three times with diethyl ether. The combined organic extracts were washed with brine and evaporated. The remaining yellow oil was co-evaporated four times with toluene to give a solid that was dried for 4 h at 40° C. under high vacuum. The title compound as obtained as light brown solid (576 mg, 60%).

1. stirringthe mixture was stirred for 4 h
2. extractionthe mixture was extracted three times with diethyl ether
3. washThe combined organic extracts were washed with brine
4. customevaporated
5. customto give a solid
6. customthat was dried for 4 h at 40° C. under high vacuum

ORD record

ord-26c9e150e1dc4f2bbf2cd61dc4cadf04

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08912221B2