Iodoethane → 1-Ethyl-3-methyl-5-nitro-1H-indazole

HRID 1094395Notes

Reaction equation

HRID 1094395 reaction equation
[CH3:1][C:2]1[C:10]2[C:5](=[CH:6][CH:7]=[C:8]([N+:11]([O-:13])=[O:12])[CH:9]=2)[NH:4][N:3]=1.[H-].[Na+].[CH2:16](I)[CH3:17]>CN(C=O)C>[CH2:16]([N:4]1[C:5]2[C:10](=[CH:9][C:8]([N+:11]([O-:13])=[O:12])=[CH:7][CH:6]=2)[C:2]([CH3:1])=[N:3]1)[CH3:17]

Participants

5

Reactant 3

HCID 6340IodoethaneHCID 24758Sodium hydrideHCID 178434304HCID 178434304, compound

Product 1

HCID 580075741-Ethyl-3-methyl-5-nitro-1H-indazoleYield 67%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 3-methyl-5-nitro-1H-indazole (1.50 g, 8.44 mmol, commercially available) in dry DMF (30 mL) under Argon was added NaH (0.43 g, 17.79 mmol) portionwise at 0° C. After 30 min, ethyl iodide (1.98 g, 1.03 mL, 12.7 mmol) was added and the mixture stirred at ambient temperature for 1 h then quenched by the addition of H2O (2 mL), concentrated and redissolved in EtOAc (30 mL) then washed with H2O (3×15 mL). The combined aqueous layers were extracted with EtOAc (3×15 mL) and the combined organic layers dried over Na2SO4, filtered and concentrated. Purification by chromatography (SiO2, heptane:ethyl acetate=95:5 to 50:50) afforded the title compound (1.17 g, 67%) as a yellow solid. MS m/e: 206.0 [M+H]−.

Workup

  1. customthen quenched by the addition of H2O (2 mL)
  2. concentrationconcentrated
  3. dissolutionredissolved in EtOAc (30 mL)
  4. washthen washed with H2O (3×15 mL)
  5. extractionThe combined aqueous layers were extracted with EtOAc (3×15 mL)
  6. dry with materialthe combined organic layers dried over Na2SO4
  7. filtrationfiltered
  8. concentrationconcentrated
  9. customPurification by chromatography (SiO2, heptane:ethyl acetate=95:5 to 50:50)

Sources & evidence

ORD record
ord-3a836214a6074c0ba10cd355a338f6a1
Source dataset
uspto-grants-2012_03
Patent number
US08133909B2

Reaction notes

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