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

HRID 1988966Notes

Reaction equation

HRID 1988966 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-8103d2cd49824dacb19721afe16d0d80
Source dataset
uspto-grants-2010_01
Patent number
US07642278B2

Reaction notes

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