Tert-Butyl nitrite → Methyl 1-acetylindazole-3-carboxylate

Methyl (2-acetamidophenyl)acetate (24.3 g, 0.12 mol) and acetic anhydride (24.3 ml, 0.26 mmol) were dissolved in acetic acid (60 ml). To the resulting solution, tert-butyl nitrite (90% purity, 18.6 ml, 0.14 mol) was added dropwise over 20 minutes under stirring at 90° C. After completion of the dropwise addition, the reaction mixture was stirred at 90° C. for further 1 hour. The reaction mixture was cooled to room temperature and then, poured in water (500 ml), followed by stirring for 1 hour. The crystals thus precipitated were collected by filtration under reduced pressure and dissolved in chloroform. The chloroform solution was washed with a saturated aqueous solution of sodium bicarbonate and saturated brine, dried over anhydrous sodium sulfate, and distilled under reduced pressure to remove the solvent, whereby methyl 1-acetylindazole-3-carboxylate (22.3 g, 85%) was obtained as a yellow solid.

1. additionAfter completion of the dropwise addition
2. stirringthe reaction mixture was stirred at 90° C. for further 1 hour
3. temperatureThe reaction mixture was cooled to room temperature
4. stirringby stirring for 1 hour
5. customThe crystals thus precipitated
6. filtrationwere collected by filtration under reduced pressure
7. dissolutiondissolved in chloroform
8. washThe chloroform solution was washed with a saturated aqueous solution of sodium bicarbonate and saturated brine
9. dry with materialdried over anhydrous sodium sulfate
10. distillationdistilled under reduced pressure
11. customto remove the solvent

ORDレコード

ord-28e170d0f4f6477c9d6a720f108ac4db

出典データセット

uspto-grants-2007_01

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07157487B2