Diisopropylethylamine → HCID 66639821, compound

Participants

Reaction Steps

To a solution of 3-methoxycarbonylmethanesulfonylamino-pyrazine-2-carboxylic acid methyl ester (Example 9.1) (1.212 g) in acetonitrile (12 ml) was added N,N-diisopropylethylamine (“Hunig's base”) (0.8 ml) at ambient temperature. The mixture was stirred at ambient temperature for 5 minutes before dropwise addition of a solution of 2,2-difluoroethyltrifluoromethanesulfonate (0.978 g) in acetonitrile (5 ml) at ambient temperature. The reaction mixture was stirred at ambient temperature for 20 hours. The reaction mixture was concentrated and the residue partitioned between ethyl acetate (30 ml) and aqueous sulfuric acid (2M) (30 ml). The phases were separated and the organic layer was concentrated. The residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane 1:2) to give 3-[(2,2-difluoro-ethyl)-methoxycarbonyl-methanesulfonyl-amino]-pyrazine-2-carboxylic acid methyl ester (0.819 g). 1H-NMR (400 MHz, CDCl3): 8.70 (d, 1H), 8.65 (d, 1H), 6.06-6.29 (m, 1H), 4.32-4.38 (m, 2H), 4.18 (s, 2H), 4.02 (s, 3H), 3.78 (s, 3H) ppm.

Provenance & Evidence