Cl[C:2]1[CH:3]=[C:4]([CH:9]=[CH:10][N:11]=1)[C:5]([O:7][CH3:8])=[O:6].[C:12]([C:16]1[S:20][C:19](B2OC(C)(C)C(C)(C)O2)=[CH:18][CH:17]=1)([CH3:15])([CH3:14])[CH3:13].C([O-])([O-])=O.[K+].[K+].C(Cl)Cl>CO.Cl[Pd]Cl.O>[C:12]([C:16]1[S:20][C:19]([C:2]2[CH:3]=[C:4]([CH:9]=[CH:10][N:11]=2)[C:5]([O:7][CH3:8])=[O:6])=[CH:18][CH:17]=1)([CH3:15])([CH3:14])[CH3:13]
Methyl 2-chloroisonicotinate (175 mg, 1.02 mmol), 2-(5-tert-butylthiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (300 mg, 1.13 mmol), K2CO3 (85 mg, 0.61 mmol) and PdCl2 (dppf) (37.3 mg, 0.05 mmol) was stirred in methanol (2 mL) and heated in a single node microwave reactor to 100° C. for 30 min. DCM (50 mL) and water (50 mL) were added, shaken and the phases separated. The aqueous phase was extracted with DCM (50 mL). The combined organic phases were dried with a phase separator and evaporated in vacuo. The residue was purified by automated flash chromatography on a Biotage® KP-SIL 50 g column. A gradient from 5% EtOAc in heptane over 2 CV followed by 5% to 20% of EtOAc in heptane over 9 CV was used as mobile phase. The product was collected using the wavelength 295 nm. The product fractions were collected and evaporated in vacuo yielding methyl 2-(5-tert-butylthiophen-2-yl)isonicotinate (213 mg, 76%). 1H NMR (600 MHz, cdcl3) δ 1.41 (s, 9H), 3.96 (s, 3H), 6.85 (d, 1H), 7.50 (s, 1H), 7.61 (d, 1H), 8.13 (s, 1H), 8.64 (d, 1H). MS m/z 276 (M+H)+
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