Diisopropylethylamine → N-cyclopropylmethoxy-2,3,4-trifluoro-benzenesulfonamide

Participants

Reaction Steps

To a stirring suspension comprised of O-cyclopropylmethyl-hydroxylamine hydrochloride (5.40 g, 0.0437 mol) in dichloromethane (20 ml) at ambient temperature under a nitrogen atmosphere was added diisopropylethylamine (10.8 ml, 0.062 mol). A solution comprised of 2,3,4-trifluorobenzenesulfonyl chloride (Oakwood Products, Inc., 1.00 g, 4.34×10−3 mol) in dichloromethane (120 ml) was added dropwise to the reaction vessel containing the stirring suspension over a 12 minute period. The reaction mixture was stirred for another 12 minutes and was quenched with 10% aqueous hydrochloric acid (140 ml). The biphasic mixture was stirred vigorously for 16 hours. The layers were separated and the organic phase was dried (MgSO4) and concentrated to 6 ml volume. The concentrated solution was administered to a flash silica column (Biotage, 90 g of silica gel). Elution with dichloromethane afforded 0.8283 g of a white amorphous solid; 68% yield; 1H-NMR (400 MHz; CDCl3 signal offset to δ 7.03; values reported are uncorrected) δ 7.50 (m,1H), 7.10 (s,1H), 6.95 (m,1H), 3.59 (d, 2H, J═7.2 Hz), 0.80 (m, 1H), 0.31 (m, 2H), 0.02 (m, 2H); 19F-NMR (376 MHz; CDCl3) δ−122.65 (m, 1F), −129.37 (m, 1F), −156.20 (m, 1F); MS (APCl−) 280 (M−1, 100), 210 (55), 195 (45).

Provenance & Evidence