Diisopropylethylamine → HCID 59623750, compound

To a solution of 3-(2-chloro-5-trifluoromethyl-phenylmethanesulfonylamino)-pyrazine-2-carboxylic acid methyl ester (Example 2.1) (0.5 g) in acetonitrile (5 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 2,2-dichloroethyltrifluoromethanesulfonate (0.603 g) at ambient temperature. The reaction mixture was stirred at ambient temperature for 20 hours. The reaction mixture was concentrated and the residue purified by column chromatography on silica gel (eluent: iso-hexane/ethyl acetate 4:1) to give 3-[(2-chloro-5-trifluoromethyl-phenylmethanesulfonyl)-(2,2-dichloro-ethyl)-amino]-pyrazine-2-carboxylic acid methyl ester as a white solid (0.179 g). 1H-NMR (400 MHz, CDCl3): 8.61 (d, 1H), 8.51 (d, 1H), 7.73 (s, 1H), 7.53-7.59 (m, 2H), 5.99-6.02 (m, 1H), 4.71 (s, 2H), 4.58 (d, 2H), 4.02 (s, 3H) ppm.