(Pyridin-4-yl)boronic acid → 4-(1,3-Diethyl-5-methyl-1H-pyrazol-4-yl)pyridine

HRID 1245587Notes

Reaction equation

[CH2:1]([N:3]1[C:7]([CH3:8])=[C:6](I)[C:5]([CH2:10][CH3:11])=[N:4]1)[CH3:2].[N:12]1[CH:17]=[CH:16][C:15](B(O)O)=[CH:14][CH:13]=1.CC(C)([O-])C.[K+]>O1CCOCC1.O.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH2:1]([N:3]1[C:7]([CH3:8])=[C:6]([C:15]2[CH:16]=[CH:17][N:12]=[CH:13][CH:14]=2)[C:5]([CH2:10][CH3:11])=[N:4]1)[CH3:2]

Participants

Conditions

Temperature: 100 °C

Procedure

A mixture of 17.05 g (64.6 mmol) of 1,3-diethyl-4-iodo-5-methylpyrazole (from Step D) and 11.9 g (105.4 mmol) of pyridine 4-boronic acid in 300 mL of dioxane was treated with a solution of 44 g (392 mmol) of potassium tert-butoxide in 100 mL of water. The resulting mixture was treated with 3.75 g (3.2 mmol) of tetrakis(triphenylphosphine)palladium(0), put under an argon atmosphere and heated at 100° C. for 18 h. The mixture was cooled and partitioned between 1 L of ether and 500 mL of water. The organic layer was separated, dried over MgSO4 and concentrated. Flash chromtography on a Biotage 75S afforded of the title compound. 1H-NMR (500 MHz) δ 1.19 (t, J=7.5, 3H), 1.48 (t, J=7.5, 3H), 2.27 (s, 3H), 2.67 (q, J=7.5, 2H), 4.09 (q, J=7.5, 2H), 7.18 (dd, J=2.0, 4.5, 2H), 8.60 (dd, J=2.0, 4.5, 2H).

Workup

temperatureThe mixture was cooled
custompartitioned between 1 L of ether and 500 mL of water
customThe organic layer was separated
dry with materialdried over MgSO4
concentrationconcentrated

Sources & evidence

ORD record: ord-e00eabd55ed2499b9567c411eb08de03
Source dataset: uspto-grants-2006_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07125887B2

Reaction notes

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