Trimethylsilylacetylene → 2-Chloro-3-fluoro-4-methyl-5-((trimethylsilyl)ethynyl)pyridine

HRID 1502467Notes

Reaction equation

[Cl:1][C:2]1[C:7]([F:8])=[C:6]([CH3:9])[C:5](I)=[CH:4][N:3]=1.[C:11]([Si:13]([CH3:16])([CH3:15])[CH3:14])#[CH:12].C(N(CC)C(C)C)(C)C>O1CCOCC1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[Cl:1][C:2]1[C:7]([F:8])=[C:6]([CH3:9])[C:5]([C:12]#[C:11][Si:13]([CH3:16])([CH3:15])[CH3:14])=[CH:4][N:3]=1

Participants

Conditions

Temperature: 60 °C

Procedure

A mixture of 2-chloro-3-fluoro-5-iodo-4-methyl-pyridine (2960 mg, 10.9 mmol), ethynyltrimethylsilane (1.89 mL, 13.1 mmol), N,N-diisopropylethylamine (3.80 mL, 21.8 mmol), dichlorobis(triphenylphosphine)palladium(II) (390 mg, 0.545 mmol), and cuprous iodide (104 mg, 0.55 mmol) in dioxane (40 mL) was heated at 60° C. for 2 hours. The reaction mixture was filtered through a short plug of silica, rinsed with 50 mL of ethyl acetate/heptane (1:1), and the filtrate was evaporated in vacuo to provide an orange oil that was purified by flash chromatography (12 g, Silica, 0-20% ethyl acetate in heptane). Desired fractions were combined and evaporated in vacuo to afford the title compound as a pale yellow oil, (2.35 mg, 89%). 1H NMR (400 MHz, CDCl3) δ 8.21 (s, 1H), 2.40 (d, J=1.9 Hz, 3H), 0.28 (s, 11H).

Workup

filtrationThe reaction mixture was filtered through a short plug of silica
washrinsed with 50 mL of ethyl acetate/heptane (1:1)
customthe filtrate was evaporated in vacuo
customto provide an orange oil that
customwas purified by flash chromatography (12 g, Silica, 0-20% ethyl acetate in heptane)
customevaporated in vacuo

Sources & evidence

ORD record: ord-7fec707bba1242838467ca9c03540fe4
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09206175B2

Reaction notes

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