Acetone → Pyridine, 3-(4-(isopropylamino)pyrazol-1-yl)-

HRID 2408174Notes

Reaction equation

HRID 2408174 reaction equation
[N:1]1[CH:6]=[CH:5][CH:4]=[C:3]([N:7]2[CH:11]=[C:10]([NH2:12])[CH:9]=[N:8]2)[CH:2]=1.[CH3:13][C:14]([CH3:16])=O.FC(F)(F)C(O)=O.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>C(OC(C)C)(=O)C>[CH:14]([NH:12][C:10]1[CH:9]=[N:8][N:7]([C:3]2[CH:2]=[N:1][CH:6]=[CH:5][CH:4]=2)[CH:11]=1)([CH3:16])[CH3:13]

Participants

6

Procedure

1-pyridin-3-yl-1H-pyrazol-4-ylamine (0.6 g, 3.7 mmol) was dissolved in isopropyl acetate (8.5 ml). To the mixture, acetone (0.261 g, 4.5 mmol), trifluoroacetic acid (0.855 g, 7.5 mmol) and sodium triacetoxyborohydride (0.945 g, 4.5 mmol) were added. The reaction was stirred under nitrogen at room temperature for 4.5 hours and then quenched with 10% sodium hydroxide solution until the pH reached ˜9. The layers were separated, and the aqueous phase was extracted with ethyl acetate. The organic extracts were combined, dried over sodium sulfate and concentrated to dryness. The crude material was purified by silica gel chromatography (gradient elution of 5% methanol/dichloromethane) to give the title compound as an off white solid (0.35 g, 46%): mp 105-107° C.; 1H NMR (300 MHz, CDCl3) δ 8.82 (d, J=2.2 Hz, 1H), 8.63 (dd, J=4.8, 1.5 Hz, 1H), 8.13 (d, J=1.8 Hz, 1H), 8.03 (d, J=2.7 Hz, 1H), 7.94-7.77 (m, 1H), 7.38 (dt, J=15.2, 7.6 Hz, 1H), 6.99 (t, 1H), 3.72 (m, 1H), 1.30 (t, J=10.0 Hz, 6H). ESIMS 214 m/z (M+1).

Workup

  1. customquenched with 10% sodium hydroxide solution until the pH
  2. customThe layers were separated
  3. extractionthe aqueous phase was extracted with ethyl acetate
  4. dry with materialdried over sodium sulfate
  5. concentrationconcentrated to dryness
  6. customThe crude material was purified by silica gel chromatography (gradient elution of 5% methanol/dichloromethane)

Sources & evidence

ORD record
ord-f6cacf7dad6343acb8fa0cc0429f29f6
Source dataset
uspto-grants-2014_08
Patent number
US08815271B2

Reaction notes

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