Hydrochloric Acid → 5-chloro-1H-indazole-3-carbaldehyde

HRID 1830011Notes

Reaction equation

HRID 1830011 reaction equation
[N:1]([O-])=O.[Na+].Cl.[Al].[Cl:7][C:8]1[CH:9]=[C:10]2[C:14](=[CH:15][CH:16]=1)[NH:13]C=C2.[O:17]1[CH2:22][CH2:21]OCC1>>[Cl:7][C:8]1[CH:9]=[C:10]2[C:14](=[CH:15][CH:16]=1)[NH:13][N:1]=[C:21]2[CH:22]=[O:17]

Participants

6

Reactant 5

HCID 313Hydrochloric AcidHCID 312751,4-DioxaneHCID 871105-ChloroindoleHCID 5359268AluminumHCID 23668193Sodium Nitrite

Product 1

HCID 1785200295-chloro-1H-indazole-3-carbaldehyde

Procedure

A 0.25 M aqueous solution of NaNO2 (1.0 equivalent) was brought to a pH of 2.5 by the addition of dilute HCl. Dioxane was added to the solution (10% by volume). The flask was protected from light with aluminum foil and 5-chloroindole (1.0 equivalent) was added slowly. The solution was stirred vigorously for 2 hours. The solution was then extracted with three portions of ethyl acetate. The organic layers were combined, washed with water, dried over MgSO4, filtered, and concentrated. The product was purified by flash chromatography (ethyl acetate:hexane, 1:1, v/v) yielding 5-chloro-1H-indazole-3-carbaldehyde as a purple solid. LC/MS (m/z) 181.3 (MH+), Rt 2.7 minutes.

Workup

  1. additionwas added slowly
  2. extractionThe solution was then extracted with three portions of ethyl acetate
  3. washwashed with water
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customThe product was purified by flash chromatography (ethyl acetate

Sources & evidence

ORD record
ord-a95e48bbb06541e3a4dd770efa5aed0b
Source dataset
uspto-grants-2006_06
Patent number
US07064215B2

Reaction notes

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