Cesium carbonate → 2-Chloro-3-methylpyrazolo[1,5-A]pyridine

HRID 530021Notes

Reaction equation

HRID 530021 reaction equation
[Cl:1][C:2]1[C:10](I)=[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][N:4]2[N:3]=1.[CH3:12]B(O)O.C(=O)([O-])[O-].[Cs+].[Cs+].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>O1CCCC1.C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[Cl:1][C:2]1[C:10]([CH3:12])=[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][N:4]2[N:3]=1

Participants

7

Reactant 4

HCID 10796Cesium carbonateHCID 11776TriphenylphosphineHCID 139377Methylboronic AcidHCID 717433402-Chloro-3-iodopyrazolo[1,5-A]pyridine

Product 1

HCID 717433412-Chloro-3-methylpyrazolo[1,5-A]pyridine

Reagents, catalysts & solvents 2

HCID 167845palladium(II) acetateCatalystHCID 8028TetrahydrofuranSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of the title compound from Example 1 Step A (0.30 g, 1.077 mmol), palladium acetate (0.024 g, 0.108 mmol), methyl boronic acid (0.129 g, 2.155 mmol), cesium carbonate (1.053 g, 3.23 mol) and triphenylphosphine (0.057 g, 0.215 mmol) in tetrahydrofuran (5.39 mL) was heated in a sealed tube at 100° C. for 18 hours. The reaction was then cooled to room temperature, filtered and concentrated under reduced pressure. Purification by column chromatography on silica gel (0-15% ethyl acetate in hexanes) provided the title compound: LCMS m/z 166.94 [M+H]+, 168.89 [M+2+H]+; 1H NMR (500 MHz, CDCl3) 8.30 (d, J=6.9 Hz, 1 H), 7.35 (d, J=8.9 Hz, 1 H), 7.10 (dd, J=7.7, 7.7 Hz, 1 H), 6.70 (dd, J=6.6, 6.6 Hz, 1 H), 2.30 (d, J=1.2 Hz, 3 H).

Workup

  1. temperatureThe reaction was then cooled to room temperature
  2. filtrationfiltered
  3. concentrationconcentrated under reduced pressure
  4. customPurification by column chromatography on silica gel (0-15% ethyl acetate in hexanes)

Sources & evidence

ORD record
ord-f7821b28923248378453b26027e50055
Source dataset
uspto-grants-2016_05
Patent number
US09351973B2

Reaction notes

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