Triethylamine → 2-(2-(3-Methoxyphenyl)ethynyl)-5-methylpyridine

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-methyl-2-trimethylsilanylethynylpyridine (5.32 mmol) in 25 mL degassed N,N-dimethylformamide was added successively 3-bromoanisole (6.96 mmol), CuI (0.57 mmol), Et3N (21.2 mmol) and trans-dichlorobis(triphenylphosphine)palladium (29 mmol). The resulting mixture was warmed to 70° C., Bu4NF (5.85 mmol) was added drop-wise, and the reaction was stirred at this temperature 2 h. After cooling, 20 mL of H2O was added and the resulting solution was extracted with EtOAc (4×20 mL). The organic layer was washed with saturated NaCl (3×20 mL), dried over Na2SO4 and evaporated to dryness. Purification of the residue by column chromatography provided M-5MPEP in 52% yield as a yellow oil. HCl salts were prepared by adding 2 M HCl/Et2O to a solution of free base in EtOAc and isolated by suction filtration. 1H NMR (CDC13) δ ppm: 2.20 (s, 3H, CH3); 3.67 (s, 3H, CH3); 6.79 (ddd, 1H, J=8.5, 2.5, 1.0 Hz, CHAr); 7.01-7.02 (m, 1H, CHAr); 7.07 (dt, 1H, J=8.5, 1.0 Hz, CHAr); 7.13 (t, IH, J=8.5 Hz, CHAr); 7.29 (d, 1H, J=7.5 Hz, CHAr); 7.33 (dd, 1H, J=7.5, 2.5 Hz, CHAr); 8.32 (s, 1H, CHAr). 13C NMR (CDCh) δ ppm: 18.8 (1C, CH3); 55.6 (1C, CH3); 88.8 (1C, C═C); 88.9 (1C, C═C); 115.9 (1C, CHAr); 116.9 (1C, CHAr); 123.8 (1C, Cq); 124.6 (1C, CHAr); 127.0 (1C, CHAr); 129.6 (1C, CHAr); 133.1 (1C, Cq); 137.0 (1C, CHAr); 140.8 (1C, Cq); 150.9 (1C, CHAr); 159.6 (1C, Cq). HCl salt mp 171-172° C. Anal. C 15H13NO HC1 0.2H20) C, H, N.

Provenance & Evidence