Hydrochloric Acid → 5-Iodo-1H-indazole

Temperatur

-5 °C

5-Aminoindazole (64.73 g, 486.13 mmol) was suspended in 600 mL water and ca. 600 mL ice, and conc. HCl (200 mL, 5759 mmol) was added. The mixture was cooled in an ice-salt bath to ca. −5° C. To this mixture was added, dropwise, a solution of sodium nitrite (37.34 g, 541.2 mmol) in 200 mL water (took about 1 hr). The internal temperature was kept below ca. +2° C. The resulting brown solution was stirred for a further 15 min at −5° C., then a solution of potassium iodide (97 g, 584.34 mmol) in 250 mL water was slowly added dropwise (took about 30 min). After complete addition, the reaction was heated to 90° C. for 1.5 hr. After allowing to cool, the solution was filtered to give a fine black solid and the filtrate was allowed to sit overnight in the refrigerator. The next day the filtrate was filtered again and the two solids were combined and dried to give 5-iodoindazole (126.63 g, 106%).

1. additionTo this mixture was added
2. customwas kept below ca. +2° C
3. additionAfter complete addition
4. temperaturethe reaction was heated to 90° C. for 1.5 hr
5. temperatureto cool
6. filtrationthe solution was filtered
7. customto give a fine black solid
8. waitto sit overnight in the refrigerator
9. filtrationThe next day the filtrate was filtered again
10. customdried

ORD-Eintrag

ord-0ab7c5e97e554acca99fbf1b7ba5979d

Quelldatensatz

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08198456B2