Potassium Carbonate → 3-(3,5-Difluorophenyl)-2-ethylpyrazolo[1,5-a]pyridine

HRID 408802Notes

Reaction equation

[CH2:1]([C:3]1[C:11](I)=[C:6]2[CH:7]=[CH:8][CH:9]=[CH:10][N:5]2[N:4]=1)[CH3:2].[F:13][C:14]1[CH:15]=[C:16](B(O)O)[CH:17]=[C:18]([F:20])[CH:19]=1.C(=O)([O-])[O-].[K+].[K+]>O1CCOCC1.O.C(OCC)(=O)C>[F:13][C:14]1[CH:15]=[C:16]([C:11]2[C:3]([CH2:1][CH3:2])=[N:4][N:5]3[CH:10]=[CH:9][CH:8]=[CH:7][C:6]=23)[CH:17]=[C:18]([F:20])[CH:19]=1

Participants

Conditions

Temperature: 100 °C

Procedure

2-Ethyl-3-iodopyrazolo[1,5-a]pyridine (0.5 g, 2.0 mmol) and (3,5-difluorophenyl)boronic acid (0.35 g, 2.2 mmol) [Aldrich 471925] were stirred in dioxane (12 mL). A solution of potassium carbonate (0.29 g, 2.1 mmol) in water (2.8 mL) was added. Tetrakis-(triphenylphosphine)palladium(0) (0.13 g, 0.1 mmol) was added and the mixture was heated at 100° C. for 16 h. After cooling, the mixture was diluted with ethyl acetate and washed with water and brine. The extracts were dried over magnesium sulfate, filtered, concentrated and purified on silica gel with ethyl acetate in hexanes (0-10%) to give the desired compound (0.41 g, 80%). LCMS for C15H13F2N2 (M+H)+: m/z=259.2. 1H NMR (300 MHz, DMSO-d6): δ 8.67 (m, 1H), 7.64 (m, 1H), 7.25 (m, 1H), 7.18 (m, 3H), 6.90 (m, 1H), 2.89 (m, 2H), 1.22 (m, 3H).

Workup

temperatureAfter cooling
washwashed with water and brine
dry with materialThe extracts were dried over magnesium sulfate
filtrationfiltered
concentrationconcentrated
custompurified on silica gel with ethyl acetate in hexanes (0-10%)

Sources & evidence

ORD record: ord-50cdc95021744e579493276c99fbd4b0
Source dataset: uspto-grants-2014_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08759359B2

Reaction notes

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