Ethyl trifluoromethanesulphonate → HCID 59623724, Verbindung

To a solution of 3-(2-chloro-5-trifluoromethyl-phenylmethanesulfonylamino)-pyrazine-2-carboxylic acid methyl ester (Example 2.1) (1.5 g) in acetonitrile (20 ml) was added N,N-diisopropylethylamine (“Hunig's base”) (0.71 ml) at ambient temperature. The mixture was stirred for 5 minutes at ambient temperature before dropwise addition of a solution of ethyltrifluoromethanesulfonate (0.71 ml) in acetonitrile (5 ml) at ambient to temperature. The reaction mixture was stirred at ambient temperature for 4 hours. The reaction mixture was concentrated and the residue purified by column chromatography on silica gel (eluent: dichloromethane) to give 3-[(2-chloro-5-trifluoromethyl-phenyl-methanesulfonyl)-ethyl-amino]-pyrazine-2-carboxylic acid methyl ester as a beige solid (0.968 g). 1H-NMR (400 MHz, CDCl3): 8.57 (d, 1H), 8.52 (d, 1H), 7.77 (m, 1H), 7.50-7.56 (m, 2H), 4.64 (m, 2H), 4.01 (q, 2H), 4.00 (s, 3H), 1.23 (t, 3H) ppm.