Hydrochloric Acid → HCID 22291456, compound

HRID 968126Notes

Reaction equation

HRID 968126 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]3[C:15]4[CH:17]=[C:18]([N+:21]([O-:23])=[O:22])[CH:19]=[CH:20][C:14]=4[CH2:13][CH2:12][C:11]=3[C:10]([C:24]([O:26]CC)=[O:25])=[N:9]2)=[CH:4][CH:3]=1.[OH-].[Na+].Cl>C1COCC1.C(OCC)(=O)C>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]3[C:15]4[CH:17]=[C:18]([N+:21]([O-:23])=[O:22])[CH:19]=[CH:20][C:14]=4[CH2:13][CH2:12][C:11]=3[C:10]([C:24]([OH:26])=[O:25])=[N:9]2)=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 22291771HCID 22291771, compound

Product 1

HCID 22291456HCID 22291456, compoundYield 97.1%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 8857Ethyl AcetateSolvent

Procedure

A suspension of ethyl 1-(4-bromophenyl)-8-nitro-4,5-dihydro-1H-benzo[g]indazole-3-carboxylate (4.4 g) in THF (80 mL) was treated with 1 N aq. NaOH (80 mL) and stirred vigorously overnight. The reaction mixture was diluted with ethyl acetate and acidified to pH=2 with 1 N aq. HCl. The organic layer was separated and the aqueous fraction extracted with EtOAc (3×). Combined extracts were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo to afford 4.0 g (97%) of 1-(4-bromophenyl)-8-nitro-4,5-dihydro-1H-benzo[g]indazole-3-carboxylic acid as a solid: MS(ESI+) 414 [M+H]+. 1H NMR (400 MHz, d6 DMSO) δ 8.07 (dd, 1H), 7.83 (d, 2H), 7.66 (d, 1H), 7.56 (d, 2H), 7.42 (d, 1H), 3.10 (m, 2H), 2.99 (m, 2H).

Workup

  1. customThe organic layer was separated
  2. extractionthe aqueous fraction extracted with EtOAc (3×)
  3. washCombined extracts were washed with brine
  4. dry with materialdried over Na2SO4
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-1ff0d401fa094de99a4926e791c7df2e
Source dataset
uspto-grants-2005_10
Patent number
US06956052B2

Reaction notes

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