Hydrochloric Acid → 1,2-Dihydro-5-nitro-1-(phenylmethyl)-3H-indazol-3-one

HRID 490551Notes

Reaction equation

HRID 490551 reaction equation
F[C:2]1[CH:10]=[CH:9][C:8]([N+:11]([O-:13])=[O:12])=[CH:7][C:3]=1[C:4]([OH:6])=O.CN(C(ON1N=NC2C=CC=CC1=2)=[N+](C)C)C.[B-](F)(F)(F)F.C(N(C(C)C)C(C)C)C.[CH:45]1[CH:50]=[CH:49][C:48]([CH2:51][NH:52][NH2:53])=[CH:47][CH:46]=1.Cl.Cl.Cl>CN(C=O)C>[CH2:51]([N:52]1[C:2]2[C:3](=[CH:7][C:8]([N+:11]([O-:13])=[O:12])=[CH:9][CH:10]=2)[C:4](=[O:6])[NH:53]1)[C:48]1[CH:49]=[CH:50][CH:45]=[CH:46][CH:47]=1

Participants

7

Reactant 5

HCID 313Hydrochloric AcidHCID 81531DiisopropylethylamineHCID 146540Benzylhydrazine dihydrochlorideHCID 2809972-Fluoro-5-nitrobenzoic acidHCID 2733207O-(Benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate

Product 1

HCID 3849951,2-Dihydro-5-nitro-1-(phenylmethyl)-3H-indazol-3-oneYield 35.7%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 2-fluoro-5-nitrobenzoic acid (0.5 g) in DMF (9 mL) was added TBTU (1.04 g) followed by N-ethyldiisopropylamine (2.3 mL). After 10 minutes benzylhydrazine.2HCl (0.63 g) was added. The reaction mixture was stirred at ambient temperature for 22 hours and the reaction was poured onto aqueous 1N HCl solution and extracted with EtOAc. The organic layer was washed with brine, dried over sodium sulfate, filtered and evaporated in vacuo. Purification via ISCO combiflash chromatography afforded pure desired 1-benzyl-5-nitro-1,2-dihydro-indazol-3-one (0.26 g) as a yellow solid. MS (ESI−):268.3 ([M−H]−).

Workup

  1. extractionextracted with EtOAc
  2. washThe organic layer was washed with brine
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. customevaporated in vacuo
  6. customPurification via ISCO combiflash chromatography

Sources & evidence

ORD record
ord-c29723ba24224e10a59bfe12c3fb473a
Source dataset
uspto-grants-2009_05
Patent number
US07528158B2

Reaction notes

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