Diethyl (ethoxymethylene)malonate → HCID 22252500, compound

Temperature

120 °C

A mixture of 5-amino-3-methylisoxazole (5.26 g) and diethyl ethoxymethylenemalonate (10.9 ml) was heated at 120° C. for 3 hrs. The mixture was cooled to room temperature. The precipitated solid was collected, washed with n-hexane and dried under high vacuum. A portion of this solid (11.37 g) was dissolved in phosphoryl chloride (55 ml), heated at reflux for 11 hrs, and then cooled to room temperature. The mixture was concentrated under reduced pressure and the residue was purified with the column chromatography(ethyl acetate: n-hexane=1:9) to give ethyl 3-methylisoxazolo[5,4-b]pyridine-5-carboxylate as a white solid. Zinc powder (2.75 g) was added to a solution of a portion of the solid (2.43 g) in acetic acid (24 ml), the was stirred at 80° C. for 1.5 hrs, and then filtered. The filtrate was concentrated under reduced pressure. The residue was dissolved in a mixture of 5N NaOH (10 ml) and ethanol (10 ml), the solution was refluxed for 1.5 hrs, cooled to room temperature, and acidified with concentrated HCl. The precipitated solid was collected by the filtration, washed with water, and dried under high vacuum.

1. temperatureThe mixture was cooled to room temperature
2. customThe precipitated solid was collected
3. washwashed with n-hexane
4. customdried under high vacuum
5. dissolutionA portion of this solid (11.37 g) was dissolved in phosphoryl chloride (55 ml)
6. temperatureheated
7. temperatureat reflux for 11 hrs
8. temperaturecooled to room temperature
9. concentrationThe mixture was concentrated under reduced pressure
10. customthe residue was purified with the column chromatography(ethyl acetate: n-hexane=1:9)

ORD record

ord-7763fd0a8b4f409bb8c1b4af31778f03

Source dataset

uspto-grants-2006_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06992086B2