Dichloromethane → 4-cyano-5-ethyl-1-methyl-3-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrrole-2-carboxylic acid ethyl ester

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Reaction Steps

Add 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (0.87 mL, 6.0 mmol) to 4-cyano-5-ethyl-3-iodo-1-methyl-1H-pyrrole-2-carboxylic acid ethyl ester (1.0 g, 3.0 mmol, prepared in prepared in Preparation 38), [1,1′-bis(diphenylphosphino)ferrocene]dichloro-palladium(II) complex with methylene chloride (1:1) (0.122 g, 0.15 mmol), and triethylamine (1.25 mL, 9.0 mmol) in acetonitrile and heat to reflux. After 3 hours, cool and pour into water. Extract with ethyl acetate. Wash the combined organics with water and brine, dry over magnesium sulfate, filter and concentrate under reduced pressure. Purify the residue by flash chromatography (silica gel), eluting with ethyl acetate:hexanes to provide the title compound. 1H NMR (400 MHz, CDCl3) δ 4.33 (q, 2H), 3.84 (s, 3H), 2.80 (q, 2H), 1.40 (s, 12H), 1.46 (t, 3H), 1.22 (t, 3H).

Provenance & Evidence