Benzene → Ethyl 6-cyclopropyl-1-{[4-(methyloxy)phenyl]methyl}-1H-pyrazolo[3,4-b]pyridine-4-carboxylate

HRID 476037Notes

Reaction equation

HRID 476037 reaction equation
[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]([CH2:9][N:10]2[C:14]([NH2:15])=[CH:13][CH:12]=[N:11]2)=[CH:5][CH:4]=1.[CH:16]1([C:19](=O)[CH2:20][C:21](=O)[C:22]([O:24][CH2:25][CH3:26])=[O:23])[CH2:18][CH2:17]1.C1C=CC=CC=1>CC(O)=O>[CH:16]1([C:19]2[CH:20]=[C:21]([C:22]([O:24][CH2:25][CH3:26])=[O:23])[C:13]3[CH:12]=[N:11][N:10]([CH2:9][C:6]4[CH:5]=[CH:4][C:3]([O:2][CH3:1])=[CH:8][CH:7]=4)[C:14]=3[N:15]=2)[CH2:17][CH2:18]1

Participants

5

Conditions

Temperature
63 °C

Procedure

A mixture of 1-{[4-(methyloxy)phenyl]methyl}-1H-pyrazol-5-amine (3 g, 14.76 mmol), ethyl 4-cyclopropyl-2,4-dioxobutanoate (2.72 g, 14.76 mmol) and benzene (50 mL) were heated at 63° C. for 16 h. The solvent was removed under reduced pressure. The crude residue was purified via silica gel chromatography (eluent: 0 to 25% EtOAc:Hex) to afford 2.56 g of the desired cyclized product and 1.71 g of the uncyclized adduct. The uncyclized adduct was dissolved in 25 mL of AcOH and heated to reflux for 16 hours. The solvent was removed under reduced pressure and the residue purified via silica gel chromatography (eluent: 0 to 25% EtOAc:Hex) to afford an additional 1.15 g of the desired cyclized product (combined yield=71%). LCMS E-S (M+H)=352.3. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.07-1.13 (m, 4H) 1.38 (t, J=7.07 Hz, 3H) 2.39 (s, 1H) 3.67 (s, 3H) 4.41 (q, J=7.07 Hz, 2H) 5.51 (s, 2H) 6.84 (d, J=8.84 Hz, 2H) 7.21 (d, J=8.59 Hz, 2H) 7.64 (s, 1H) 8.23 (s, 1H).

Workup

  1. customThe solvent was removed under reduced pressure
  2. customThe crude residue was purified via silica gel chromatography (eluent: 0 to 25% EtOAc:Hex)
  3. customto afford 2.56 g of the
  4. temperatureheated
  5. temperatureto reflux for 16 hours
  6. customThe solvent was removed under reduced pressure
  7. customthe residue purified via silica gel chromatography (eluent: 0 to 25% EtOAc:Hex)
  8. customto afford an additional 1.15 g of the desired cyclized product (combined yield=71%)

Sources & evidence

ORD record
ord-713cd5c3e0594749bf8f50e8b71e09a0
Source dataset
uspto-grants-2014_01
Patent number
US08637509B2

Reaction notes

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