Triethylamine → 4-(3-Methoxy-prop-1-ynyl)-3-methyl-benzofuran-2-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To the product of Example 20, Step 1, 3-methyl-4-trifluoromethanesulfonyloxy-benzofuran-2-carboxylic acid ethyl ester (860 mg, 2.4 mmol, 1 eq), in 7 mL of DMF under nitrogen was added 98 mg of PdCl2(PPh3)2 (0.14 mmol, 0.06 eq), 0.42 mL of 3-methoxy-propyne (5.0 mmol, 2.1 eq) and 1.36 mL of triethylamine (9.7 mmol, 4.0 eq). The reaction mixture was heated to 90° C. for 18 h. After work up and column chromatography (4% ethyl acetate/hexane), 4-(3-methoxy-prop-1-ynyl)-3-methyl-benzofuran-2-carboxylic acid ethyl ester was obtained in 53% yield (343 mg). 1H NMR (400 MHz, CDCl3) δ ppm 1.4 (t, J=7.2 Hz, 3 H) 2.8 (t, 3 H) 3.5 (s, 3 H) 4.4 (s, 2 H) 4.5 (q, J=7.2 Hz, 2 H) 7.4 (m, 2 H) 7.5 (dd, J=7.7, 1.6 Hz, 1 H)

Herkunft & Nachweise