Isobutyraldehyde → HCID 68677340, compound

Temperature

-30 °C

A flame-dried flask was charged with THF (3.0 mL) and 423 mg of 2,2,6,6-tetramethylpiperidine. The solution was cooled to −30° C. and 1.0 mL of a 2.5 M solution of n-butyllithium in hexanes was added dropwise. The mixture was warmed to 0° C. for 20 min. and then cooled to −78° C. A solution of 226 mg of 6-tert-butyl-8-chloro-2H-[1,2,4]triazolo[4,3-a]pyrazin-3-one in THF (2.0 mL) was added dropwise and the resulting solution was stirred for one h prior to the addition of 129 mg of isobutyraldehyde. The mixture was warmed to 0° C. and the reaction was quenched by the addition of sat. ammonium chloride solution followed by adjusting the pH of the solution to 3.0 with 2N HCl. The mixture was extracted with EtOAc and the organic layer was washed with sat. sodium chloride solution, dried over sodium sulfate, filtered, and concentrated. The residue was purified by silica gel chromatography to provide 6-tert-butyl-8-chloro-5-(1-hydroxy-3-methyl-butyl)-2H-[1,2,4]triazolo[4,3-a]pyrazin-3-one as a white solid. MS (M+H+)=313.4.

1. temperatureThe mixture was warmed to 0° C. for 20 min.
2. temperaturecooled to −78° C
3. temperatureThe mixture was warmed to 0° C.
4. customthe reaction was quenched by the addition of sat. ammonium chloride solution
5. extractionThe mixture was extracted with EtOAc
6. washthe organic layer was washed with sat. sodium chloride solution
7. dry with materialdried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified by silica gel chromatography

ORD record

ord-af82ddc8eb5b439792f630d0b61eb976

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07709473B2