Phenylhydrazine → 1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-5-amine

HRID 63248

Reaction equation

[C:1]1([NH:7][NH2:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.O=[C:10]([C:14]1[S:15][CH:16]=[CH:17][CH:18]=1)[CH2:11][C:12]#[N:13]>CO>[C:1]1([N:7]2[C:12]([NH2:13])=[CH:11][C:10]([C:14]3[S:15][CH:16]=[CH:17][CH:18]=3)=[N:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

Conditions

Temperature: 120 °C

Procedure

Phenyl hydrazine (143 mg, 1.32 mmol) and 3-oxo-3-(2-thienyl)propionitrile (200 mg, 1.32 mmol) were placed in a microwave vial and dissolved in methanol (660 μL). The vial was sealed, placed in a microwave oven and heated at 120° C. for 40 minutes. After this period, the reaction mixture was concentrated to dryness in vacuo. The residue was redissolved in ethyl acetate and the organic solution washed with water, saturated aqueous NaHCO3 and brine, respectively. The organic layer was dried over anhydrous Na2SO4 and concentrated. The crude material was purified by flash chromatography (20-50% ethyl acetate/hexanes gradient) to afford the desired intermediate, 2-phenyl-5-thiophen-2-yl-2H-pyrazol-3-ylamine (315 mg).

Workup

customThe vial was sealed
customplaced in a microwave oven
waitAfter this period
concentrationthe reaction mixture was concentrated to dryness in vacuo
dissolutionThe residue was redissolved in ethyl acetate
washthe organic solution washed with water, saturated aqueous NaHCO3 and brine
dry with materialThe organic layer was dried over anhydrous Na2SO4
concentrationconcentrated
customThe crude material was purified by flash chromatography (20-50% ethyl acetate/hexanes gradient)

Sources & evidence

ORD record: ord-26c563fc2f134b24934e647c6b2a3e34
Source dataset: uspto-grants-2016_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09447058B2

Linked notes

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