Water → 2-(4-Chlorophenyl)-5-cyclopropyl-6-nitro-2H-indazole-3-carboxylic acid

HRID 63528Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]([C:17]#N)=[C:15]3[C:10]([CH:11]=[C:12]([N+:22]([O-:24])=[O:23])[C:13]([CH:19]4[CH2:21][CH2:20]4)=[CH:14]3)=[N:9]2)=[CH:4][CH:3]=1.[OH2:25].[OH-:26].[Na+]>CCO>[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:16]([C:17]([OH:26])=[O:25])=[C:15]3[C:10]([CH:11]=[C:12]([N+:22]([O-:24])=[O:23])[C:13]([CH:19]4[CH2:21][CH2:20]4)=[CH:14]3)=[N:9]2)=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 90 °C

Procedure

To a stirred solution of (v) (20 g, 0.06 mol) in EtOH:water (400 ml, 1:1 v/v) was added NaOH (59.0 g, 0.02 mol) and the reaction mixture heated at 90° C. for 15 h. The reaction was then cooled to RT and the volatiles were removed in vacuo. The residual aqueous solution was acidified to pH 2 with aq. 2N HCl solution whereupon a solid precipitated from solution. The solid was separated by filtration and dissolved in EtOAc (300 mL), dried (Na2SO4) and concentrated in vacuo to give (vi) (7.5 g, with purity 75% by HPLC analysis). The material was used unpurified in subsequent steps.

Workup

temperatureThe reaction was then cooled to RT
customthe volatiles were removed in vacuo
customprecipitated from solution
customThe solid was separated by filtration
dissolutiondissolved in EtOAc (300 mL)
dry with materialdried (Na2SO4)
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-616b5a9e4eff4e59a5082410877cdea5
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09447080B2

Reaction notes

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