2-Fluoroethanol → 3-(2-Fluoroethoxy)-pyrid-2-ylsulfonamide

Reaction equation

[F:1][CH2:2][CH2:3][OH:4].[H-].[Na+].F[C:8]1[C:9]([S:14]([NH2:17])(=[O:16])=[O:15])=[N:10][CH:11]=[CH:12][CH:13]=1>O1CCCC1>[F:1][CH2:2][CH2:3][O:4][C:8]1[C:9]([S:14]([NH2:17])(=[O:16])=[O:15])=[N:10][CH:11]=[CH:12][CH:13]=1

Participants

Procedure

5.76 ml of 2-fluoroethanol are added dropwise, with cooling, to a suspension of 6.54 g of sodium hydride (55.6% NaH in oil) in 120 ml of tetrahydrofuran so that the temperature does not exceed 20° C. When the dropwise addition is complete, the reaction mixture is stirred at room temperature for 15 minutes and then a further solution of 10.56 g of 3-fluoro-pyrid-2-ylsulfonamide in 60 ml of tetrahydrofuran is added dropwise over a period of 10 minutes. The reaction solution is then stirred for 10 minutes at room temperature and for 2 hours at reflux before it is cooled and concentrated. For purification, the oil remaining is chromatographed on a silica gel column using ethyl acetate/hexane 4/1. Evaporation of the eluant yields a light-coloured oil which crystallises spontaneously, yielding 5.88 g of title product which melts at 122°-123° C.