2,6-Lutidine → HCID 70674568, compound

Participants

Reaction Conditions

Reaction Steps

A solution of (S)-3-cyclopentyl-2-(1-oxo-4-trifluoromethyl-1,3-dihydro-isoindol-2-yl)-propionic acid (prepared as in Example 1, 160 mg, 0.47 mmol) in methylene chloride (10 mL) and N,N-dimethylformamide (1 drop) cooled to 0° C. was treated with a solution of oxalyl chloride in methylene chloride (2.0 M, 281 μL, 0.56 mmol) and stirred at 0° C. for 15 min. After this time, the reaction mixture was warmed to room temperature and then stirred for another 30 min. After this time, the reaction mixture was then concentrated in vacuo to ˜1 mL volume and an additional amount of methylene chloride (3 mL) was added. One half of this solution of prepared acid chloride (2 mL, 0.23 mmol) was added dropwise to a separate reaction flask containing a mixture of pyrazin-2-ylamine (33 mg, 0.35 mmol) and 2,6-lutidine (52 μL, 0.47 mmol) in methylene chloride (5 mL) cooled to 0° C. The resulting reaction mixture was then allowed to warm to room temperature and stirred for 16 h. After such time, the reaction mixture was quenched with a saturated aqueous sodium bicarbonate solution (10 mL) and then extracted with methylene chloride (3×10 mL). The organic layers were then washed with a 1N aqueous hydrochloric acid solution (10 mL), dried over magnesium sulfate, filtered to remove the drying agent, and the filtrate concentrated in vacuo. The crude material was purified via automated flash chromatography (12 g silica gel column, 25-75% ethyl acetate/hexanes and then a 4 g silica gel column, 40-60% ethyl acetate/hexanes) to afford (S)-3-cyclopentyl-2-(1-oxo-4-trifluoromethyl-1,3-dihydro-isoindol-2-yl)-N-pyrazin-2-yl-propionamide (39 mg, 40%) as a white foam: [α]28D=−65.0° (c=0.10, methylene chloride); HR-ES(+) m/e calcd for C21H21N4O2F3 [M+H]+ 419.1690, observed 416.1688; 1H NMR (300 MHz, DMSO-d6) δ ppm 11.32 (s, 1H), 9.26 (s, 1H), 8.34-8.49 (m, 2H), 8.02 (t, J=8.45 Hz, 2H), 7.67-7.84 (m, 1H), 5.23 (dd, J=4.98, 10.41 Hz, 1H), 5.06 (d, J=18.41 Hz, 1H), 4.67-4.85 (m, 1H), 1.02-2.21 (m, 11H).

Provenance & Evidence