Triethylamine → 2-Methylsulfanyl-5-(2-methylphenyl)ethynylpyrimidine-4-carboxylic acid methyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 1-ethynyl-2-methylbenzene (0.53 g, 4.6 mmol), 5-bromo-2-methylsulfanylpyrimidine-4-carboxylic acid methyl ester (11.0 g, 3.8 mmol), triethylamine (2.5 ml), triphenylphosphine (0.125 g, 0.48 mmol), copper (I) iodide (0.025 g, 0.13 mmol), bistriphenyphosphinepalladium (II) dichloride (0.10 g, 0.14 mmol) and dimethylformamide (1 ml) was stirred in a heavy-walled Smith process vial and irradiated with microwaves to maintain 100° C. for 20 min. The cooled mixture was diluted with dichloromethane (20 ml) and washed with 5% hydrochloric acid (20 ml), water (20 ml), saturated aqueous sodium hydrogencarbonate solution (20 ml) and water (20 ml) then dried (MgSO4) and evaporated in vacuo. The residual oil was purified by flash column chromatography over silica using a 1:4 mixture of hexane and dichloromethane as eluant. Appropriate fractions were combined and the solvents removed in vacuo to give 2-methylsulfanyl-5-(2-methylphenyl)ethynylpyrimidine-4-carboxylic acid methyl ester (0.9 g) as an orange oil. 250 MHz 1H-NMR (CDCl3) δ (ppm): 2.45 (s, 3H) (ArCH3), 2.55 (s, 3H) (—SCH3), 3.95 (s, 3H)(CO2CH3), 7.05-7.25 (m, 3H) (3×ArH), 7.45 (m, 1H) (ArH), 8.7 (s, 1H) (ArH); m/z (M+H)+. 299, HPLC purity 96%, HPLC retention time 4.15 min.

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