Triphenylphosphine → 5-Cyclopropyl-2-(5-methylpyridin-2-yl)-6-nitro-2H-indazole

HRID 2202566Notes

Reaction equation

[CH:1]1([C:4]2[C:5]([N+:15]([O-:17])=[O:16])=[CH:6][C:7]([N+:12]([O-])=O)=[C:8]([CH:11]=2)[CH:9]=O)[CH2:3][CH2:2]1.[CH3:18][C:19]1[CH:20]=[CH:21][C:22]([NH2:25])=[N:23][CH:24]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>CCO.C(Cl)Cl>[CH:1]1([C:4]2[C:5]([N+:15]([O-:17])=[O:16])=[CH:6][C:7]3[C:8](=[CH:9][N:25]([C:22]4[CH:21]=[CH:20][C:19]([CH3:18])=[CH:24][N:23]=4)[N:12]=3)[CH:11]=2)[CH2:3][CH2:2]1

Participants

Conditions

Temperature: 100 °C

Procedure

To a stirred solution of (iv) (50 mg, 0.212 mmol) in EtOH (750 mL) was added 5-methylpyridin-2-amine (25 mg, 0.23 mmol) and the resultant solution stirred at RT for 2d, after which time a solid precipitated from solution. Triphenylphosphine (167 mg, 0.64 mmol) was added in a single portion and the reaction then heated at 100° C. in a sealed tube for 4 h. Upon cooling to RT, the reaction mixture was diluted with DCM (2 mL) and the organics were washed with aq. 30% hydrogen peroxide solution (2 mL). The organics were separated and filtered through a plug of MgSO4 and then purified by automated column chromatography (Biotage SP4, Grace 4 g silica cartridge) eluting with EtOAc:n-heptane (gradient elution, 0% equil. (2 CV), 0% (1 CV), 0 to 100% (35 CV), 100% (5 CV)) to give (v) (27 mg, 43%). ESI-MS: calculated [M+H]+ 295.1, observed [M+H]+ 295.2.

Workup

customafter which time a solid precipitated from solution
customthe reaction
temperatureUpon cooling to RT
washthe organics were washed with aq. 30% hydrogen peroxide solution (2 mL)
customThe organics were separated
filtrationfiltered through a plug of MgSO4
custompurified by automated column chromatography (Biotage SP4, Grace 4 g silica cartridge)
washeluting with EtOAc

Sources & evidence

ORD record: ord-47c472e565954f8d8bce1bcaf2f483b4
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09365554B2

Reaction notes

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