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

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).

1. additionwas added dropwise to the reaction vessel
2. additioncontaining the stirring suspension over a 12 minute period
3. customwas quenched with 10% aqueous hydrochloric acid (140 ml)
4. stirringThe biphasic mixture was stirred vigorously for 16 hours
5. customThe layers were separated
6. dry with materialthe organic phase was dried (MgSO4)
7. concentrationconcentrated to 6 ml volume
8. washElution with dichloromethane

ORD record

ord-e7e03f26cc194b6c9c23ab959c1622a1

Source dataset

uspto-grants-2004_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06835749B2